OVEVRVIEW OF MARITIME FISHING SYSTEM IN BANGLADESH.
By-Md.Mazharul Islam,MBA(HRM),Southeast University
Executive Summary
Bangladesh is rich in water resources. Inland and marine waters are the main sources of fisheries production and exploitation. The area of total inland water bodies is 4.337 million ha: of which 4.047 million ha is floodplain and 0.29 million ha is Closed water bodies including coastal shrimp farms. In coastal areas, a total of 166000 km2 water area in 200 nautical miles of exclusively economic zone. There are about 260 indigenous and 12 introduced fish, and 24 prawn species that exist in the freshwater. In the marine water, a total of 480 fish and 40 shrimp species and some other economically important turtles, oysters, crabs and algae are found. In 2004-06, Bangladesh produced about 15.68 lac Mt. of fish, of which 8.00 lac Mt. was from the inland open waters, 6.68 lac. Mt. was from the Maritime waters and 1.00 lac Mt. from the coastal shrimp farms.
Fish is the principal source of animal protein in our food. Increased rates of child mortality have occurred due to deficiencies of balanced protein. However, there is an acute shortage of food in the country and expansion of livestock production is limited due to a lack of space. For this reason dependency on fish for animal protein-rich food will increase day by day. There are many possibilities for increasing the Contribution of fish to socio-economic development goals such as increasing nutrition, employment opportunities, foreign currency earnings and the establishment of different industrial organizations.
There are many obstacles to the development of the fisheries sector. These are, Conservation of fisheries resources, various natural calamities and man-made problems, lack of proper management and technically skilled manpower and lack of funds. Besides these, lack of a national fish policy is one of the important causes for not developing this sector up to the mark. To get rid of this, the National Fish Policy has been formulated.
CHAPTER ONE: INTRODUCTION OF THE STUDY
1.1. Introduction:
Bangladesh is a low laying country. It lies between the Himalayan mountains and the Bay of Bengal in the delta of the River Ganges and Brahmaputra. It commands jurisdiction over 166 000 sq. km of water area, including the 200-mile EEZ. One fifth of the population live in coastal areas. Most of them depend on marine resources for their livelihood. Fisheries plays a conspicuous role - through nutrition,
employment generation and foreign exchange earnings.
Marine fishing is largely confined within a depth of 100 meters. Nearly 130 trawlers and 52,000 mechanized and non-mechanized boats are active in fishing. Pelagic and deep-sea resources are largely untapped.
From the beginning of the world man knew the art of hunting animals and fish for providing their foods to meet their hungriness. From the ancient period men have been hunting fish to supply food for his family and himself, fishing from the sea ashore or river bank, using spears, crude hooks and lines and simple traps. When he took to the water in the first rough dugouts, his field of operations was substantially extended. As the pattern of community living developed and preservation techniques such as drying and curing became established fish became not only food for the catcher but also a staple commodity of trade. Competition and technological advances slowly brought about improvements in fishing gear and new methods of capture appropriate to the target species sought were evolved by trial and error down through the centuries. Today there is a wide range of towed fishing gear for catching fish on the seabed, just off the bottom and in mid-water suitable for all sizes of vessel working singly or in pairs. There are various types of seines used for surrounding large shoals of fish in open water or small shoals near the coast, static nets that catch fish by enmeshing them, traps for lobsters, crabs, salmon and sea trout, lines set to catch fish on baited hooks and dredges for scallops and queens.
The coastal zone of Bangladesh is diverse in function and form .Big cities like Chittagong, Khulna, Barisal and many other urban centers are located in the coastal zone. Beside agriculture; a large number of economic activities such as industry, shipping and tourism are concentrated in these areas.
The coast of Bangladesh is known as a zone of vulnerabilities as well as opportunities. It is prone to natural disasters like cyclone, storm surge and flood. The combination of natural and man-made hazards, such as erosion, high arsenic content in ground water, water logging, earthquake, water and soil salinity, various forms of pollution, risks from climate change, etc, have adversely affected lives and livelihoods in the coastal zone and slowed down the pace of social and economic developments in this region.
Because of distinctive characteristics of the coast, scope for production possibilities as well as employment opportunities vary with respect to rural, semi-urban and urban conditions. The zone has diversity of natural resources including coastal fisheries and shrimp, forest, salt and minerals. It has sites for Export Processing Zones, harbors, airports, land ports and tourism complexes and opportunity for other industries. This zone also has high potential for exploitation of both onshore and offshore natural gas. Some of these resources still remained untapped while there are opportunities for using many of them for their significant expansion potentials.
Bangladesh being a first line littoral state of Indian Ocean is having a very good source of marine resources in Bay of Bengal. Bangladesh is having an Exclusive Economic Zone of 41,000 square miles, which is 73% of the country’s land area. On the other hand, Bangladesh being a small and developing country overloaded with almost unbearable pressure of human population. In the past, people of Bangladesh were mostly dependent upon land-based proteins. But, the continuous process of industrialization and urbanization is consuming our limited land area practically everyday. Now there is no other alternative way than to harvest the vast under water protein from Bay of Bengal, which can meet up our demand.
1.2. Objective of the study :
‘This Organizational Consulting Project report’ program in any where is the way of practical learning. So, the foremost and judicial objective of the study is to handle with practical situation gathering experience and learn something that can help me in future. There are some other objectives to indicate:-
1. To know the overall Maritime Fishing Techniques of Bangladesh,
2. To find out the contribution of Marine Fisheries in Bangladesh Economy,
3. To know about Various marine fisheries resources of the Bay of Bengal,
4. To identify the problems and barriers in Marine Fisheries Sector,
5. To give some suggestions to overcome these barriers.
1.3.Methodology of the study:
Three methods have been used to obtained information, these are as follows;
(1)Practical Sources: As I am fishing mariner , I have been serving in various Sea Fishing industries for last 06 years. Here my practical knowledge was very helpful for making this internship report.
(2)Primary Source: The Primary data were collected through the following methods;
1. Field surveys,
2. Face to face interviews,
3. Telephony conversation,
4. Questionnaires etc.
(3)Secondary Source: The secondary source of these data are as follows;
1. Reference books,
2. Journals, articles, reports,
3. Magazines, newspapers,
4. Websites and internet's blogs.
1.4. Scope of the study :
As a Fishing Mariner, I got enough scope to continue my Internship reporting project. The Management Personnel, Captains and Crews/Sailors were co-operative enough. Being a marine officer (Skipper), it was not so tough for me to pick up necessary information from Marine Fisheries Department Chittagong, Ex-Cadet Association ,Mercantile Marine Dept. ctg; Marine Fisheries Academy, Chittagong.
1.5. Limitations Of The Study:
Best affords have been given to make this Report informative, analytical, and comprehensive one. Nevertheless it challenges the following factors;
1. As being a employee of higher post and responsibility I have not get enough time to prepare this report.
2. Company did not provide all necessary documentary report for its business secrecy & confidentiality.
3. Insufficient scrutiny to all departments.
4. Some employees of the company are not cooperative.
5. Lacking of sufficient recorded documents and publications.
6. For some of my personal limitation there may be short
Cuttings in the report.
CHAPTER-TWO: Maritime Fisheries Resources of Bangladesh.
2.1 Fisheries Resources in Bangladesh:
Bangladesh are rich in water resources. Inland and marine waters are the main sources of fisheries production and exploitation. The area of total inland water bodies is 4.337 million ha: of which 4.047 million ha is floodplain and 0.29 million ha is dosed water bodies including coastal shrimp farms. In coastal areas, a total of 0.166 km2 water area in 200 nautical miles of exclusively economic zone. There are about 260 indigenous and 12 introduced fish, and 24 prawn species that exist in the freshwater. In the marine water, a total of 475 fish and 36 shrimp species and some other economically important turtles, oysters, crabs and algae are found. In 1995-96, Bangladesh produced about 12.68 lac Mt. of fish, of which 5.95 lac Mt.was from the inland open waters, 3.13 lac. Mt. was from the inland closed waters and 0.77 lac Mt. from the coastal shrimp farms.Although there is great potential and scope for the fisheries sector in the economy. very little national effort has been undertaken in the recent past. In the third five-year plan, only about 1.58% the government had allocated (Tk.3500 million), whereas allocation for the agriculture sector was 24.8%. The target' for fish production was I million tonnes. In the fourth five year plan (199095), 1.78% (Tk.7500 million) was allotted for the fisheries sector. The production target was 1.2 million tonnes and the production achieved about 1.17 million tonnes. Fish is the principal source of animal protein in our food. Increased rates of child mortality have occurred due to deficiencies of balanced protein. However, there is an acute shortage of food in the country and expansion of livestock production is limited due to a lack of space. For this reason dependency on fish for animal protein-rich food will increase day by day. There are many possibilities for increasing the Contribution of fish to socio-economic development goals such as increasing nutrition, employment opportunities, foreign currency earnings and the establishment of different industrial organisations. However appropriate measures must be taken in inland waters to retain water and conservation. There are many obstacles to the development of the fisheries sector. These are, Conservation of fisheries resources, various natural calamities and man-made problems, lack of propermanagement and technically skilled manpower and lack of funds. Besides these, lack of a national fish policy is one of the important causes for not developing this sector up to the mark. To get rid of this, the National Fish Policy has been formulated.
Bangladesh is one of the resourceful countries with its wide range of marine aquatic bio-diversities. There are about 1093 marine aquatic organisms where 44.35% are finfish, 32.23% shellfish, 15.10% seaweeds and only 8.32% are other organisms including shrimps. The details in number of species and their percentages are shown in the table below:
Group of the Organisms Nos. of Species %
1 Finfish 486 44.35
2 Sharks, Rays, Skates and Dolphin 21 1.92
3 Shrimps 36 3.30
4 Lobster 6 2.01
5 Crabs 16
6 Sea Turtle 3 0.27
7 Crocodiles 3 0.27
8 Squid and Cuttle Fish 7 0.64
9 Shellfish (Univalves and bivalves) 350 32.23
10 Seaweeds 165 15.10
Total 1093 100
Chapter Three: Theoretical Framework.
World Maritime Fishing System at a glance:
3.01Beam trawl:
In this type of trawl the mouth or opening of the net is kept open by a beam which is mounted at each end on guides or skids which travel along the seabed. The trawls are adapted and made more effective by attaching tickler chains (for sand or mud) or heavy chain matting (for rough, rocky ground) depending on the type of ground being fished. These drag along the seabed in front of the net, disturbing the fish in the path of the trawl, causing them to rise from the seabed into the oncoming net. Electrified ticklers, which are less damaging to the seabed, have been developed but used only experimentally. Work is also being carried out to investigate whether square mesh panels (see below) fitted in the ‘belly’ or lower panel of the net can reduce the impact of beam trawling on communities living on or in the seabed. Modern beam trawls range in size from 4 to 12 m (weighing up to 7.5 tonnes in air) beam length, depending on the size and power of the operating vessel.
3.02 Demersal otter trawl
The demersal or bottom trawl is a large, usually cone-shaped net, which is towed across the seabed. The forward part of the net – the ‘wings’ – is kept open laterally by otter boards or doors. Fish are herded between the boards and along the spreader wires or sweeps, into the mouth of the trawl where they swim until exhausted. They then drift back through the funnel of the net, along the extension or lengthening piece and into the cod-end, where they are retained.
The selectivity of trawl fisheries may be increased by the use of devices known as separator trawls. Separator trawls exploit behavioral differences between fish species and can be used, for example, to segregate cod and plaice into the lower compartment of the net, whilst haddock are taken in the upper part. The mesh size for the two compartments can be altered according to the size of the adult fish being targeted. Insertion of square mesh panels also improves selectivity of the net because square meshes, unlike the traditional diamond shape meshes, do not close when the net is towed. Discarding of immature fish may also be reduced by increasing the basic mesh size in fishing nets. Sorting grids are compulsorily fitted in nets in some prawn and shrimp fisheries to reduce bycatch of unwanted or non-target species, including small prawns and shrimp.
Depending on the depth of water fished and the way in which the gear is constructed and rigged, trawling may be used to catch different species. Trawls can be towed by one vessel using otter boards, as in bottom-trawling, or by two vessels, each towing one warp, as in pair-trawling. Or more than one trawl can be towed simultaneously as in multi-rig trawling.
3.03 Multi-rigs:
Multi-rigs are used widely for the capture of panaeid shrimps in tropical waters and more recently for Nephrops (langoustines or Dublin Bay prawns) and deep-water prawns in temperate waters. The speed at which the net is towed is important, varying with the swimming speed of the target species from about 1.5 to 5 knots for fast swimming fish.
3.04 Dive-caught:
Free diving (using mask and snorkel) or scuba diving is a traditional method of collecting lobster, abalone, seaweed, sponges and reef dwelling fish (groupers and snappers) for example. In deeper waters helmet diving systems using air pumped from the surface are used. Species, including high value species such as geoduck (giant clam), urchins, sea cucumber, lobster and scallops are now widely harvested by divers. Hand-collection by divers is potentially one of the most species selective and least damaging fishing method, provided harvesting is carried out responsibly.
3.05 Dredging:
Dredging is used for harvesting bivalve molluscs such as oysters, clams and scallops from the seabed. A dredge is a metal framed basket with a bottom of connected iron rings or wire netting called a chain belly. The lower edge of the frame has a raking bar, with or without teeth, depending upon the species targeted. The catch is lifted off the seabed or out of the sea by the raking (or teeth) bar and passes back into the basket or bag. Depending on the size of the boat and the depth of water fished the number of dredges or ‘bags’ may vary from a single dredge towed behind the vessel to from 5 to 10 or more dredges per side. Dredges are generally attached to a towing bar and one is operated from each side of the vessel simultaneously.
3.06 Drift net:
A gill net that is allowed to drift with prevailing currents.Drift nets are not set or fixed in any way, are in fact ‘mobile’, and they are allowed to drift with the prevailing currents. Drift nets are used on the high seas for the capture of a wide range of fish including tuna, squid and shark, and off north-east England for salmon. Despite a global moratorium on large-scale drift nets (nets exceeding 2.5 kms in length), introduced in 1992, problems still exist. For example, drift net fisheries in the Mediterranean for swordfish and albacore tuna pose a particular threat to striped dolphins. An EU-wide ban on all drift nets was introduced from January 2002. The ban applies to fisheries such as tuna, shark and swordfish in all EU waters except the Baltic, and to all EU vessels on the high seas. EU fishermen are, however, considering challenging the ban if ‘pingers’ (see below) are found to be successful in deterring marine mammals from entanglement and subsequent drowning in nets.
3.07 Fish attraction devices (FADs):
Various species of fish often congregate or associate with other living creatures (e.g. tuna associate with dolphins and whale sharks ) or objects floating or suspended in the sea. This natural phenomenon has been exploited to attract fish to floating or suspended structures. Such structures can provide known locations for congregating fish, around which vessels can operate a wide range of fishing techniques including purse seines, pole and line or trolling. FADs may be used to concentrate fish in sufficiently high numbers which are then surrounded with a purse seine net. Fishermen using pole and line or trolling methods may use the boat from which they are fishing as a FAD.
3.08 Fish farming:
Aquaculture is a term used to describe the farming of marine and freshwater organisms. Mariculture only refers to the farming of marine organisms; it can be further defined as open mariculture (or semi-culture) where organisms are farmed in a natural environment, such as mussels, and closed mariculture (or intensive mariculture) where organisms are farmed in closed environments as used for some finfish such as halibut.
Currently 1 in 5 fish destined the dinner tables worldwide comes from marine or freshwater farms. Fish that are commonly grown in cages include Atlantic salmon in Europe and America; Pacific salmon in America; the yellowtail in Japan; and seabass and groupers in Greece, Malaysia and Indonesia.
In Britain, two species of fish are principally farmed: Atlantic salmon in salt- water and rainbow trout in fresh water. This is changing with the introduction of farming of new marine species such as cod, haddock and halibut. The major growth sector in UK mariculture is farmed Atlantic salmon, whose production in Scotland has nearly trebled since 1990 and is predicted to increase.
Whilst fish farming relieves pressure from exploitation of wild stocks and could be managed in a sensitive and sustainable way, the scale of most modern fish farming in the UK has led to environmental impacts that negate any overall environmental gain. MCS believes the industry has developed too rapidly and to the possible detriment of inshore marine habitats, particularly sea lochs, wild stocks of Atlantic salmon and other fisheries such as shellfisheries.
One of the biggest impacts of fish farming on the marine environment is the production of fishmeal used to feed farmed fish. The protein for this fishmeal is sourced from small pelagic fish that are not targeted for human consumption, but form the base of the food chain and are important prey for other species such as cod .
3.09 Gill or Fixed nets:
Gill nets are walls of netting which may be set at or below the surface, on the seabed, or at any depth inbetween. Gill netting is probably the oldest form of net fishing, having been in use for thousands of years. True gill nets catch fish that attempt to swim through the net, which are caught if they are of a size large enough to allow the head to pass through the meshes but not the rest of the body. The fish then becomes entangled by the gills as it attempts to back out of the net. The mesh size used depends upon the species and size range being targeted.
Tangle nets resemble gill nets but are slacker, shorter and have less flotation. This results in a looser-hung net that entangles species rather than gilling them.
Trammel nets are a wall of net divided into three layers. An inner fine-meshed net is sandwiched between two outer, larger meshed nets. The net is anchored at the base and floated by the headline, allowing it to hang vertically. The inner net is looser than the outer ones, ensuring that the fish become entangled within it.
Although static gears such as gill nets generally have less impact on the environment than mobile or towed gears they pose a particular problem for cetaceans (dolphins and porpoise). Methods to increase the ‘dolphin-friendliness’ of this fishing method include the attachment of acoustic devices or ‘pingers’ to the net to deter the animals; reducing the ‘soak time’,; i.e. the amount of time the net is left in the water;restrictions on the length of net used; and the introduction of closed areas to exclude fishermen from cetacean 'hot-spots'.
3.10 Handline:
Fishing with lines and hooks is one of the oldest fishing methods. They may be used from a stationary or moving boat. The catch is of very high quality as the fish is usually live when brought aboard.Handlining is also a highly selective fishery in terms of species and size. The method can be used while fish are spawning, as they will normally only bite after completion of spawning. Handlining is used to catch cod and other demersal species and pelagic species such as mackerel, squid and tuna . In tropical waters handlines are used to catch groupers and snappers. Because hauling is slow, mechanised (electrical or hydraulic) systems have been developed to allow more lines to be worked by a smaller crew.
3.11Jigging
Jigging is widely used to capture squid. A jig is a type of grapnel, attached to a line, which may be manually or mechanically jerked in the water to snag the fish in its body. Jig fishing usually happens at night with the aid of light attraction.
3.12Trolling:
Trolling involves towing baited hooks or lures through the water. The method is particularly suited to the capture of pelagic species of high individual value. Examples include tuna (albacore and skipjack), wahoo, dorado, barracuda and salmon.
3.13 Hand-gathering (picking) or collection:
Traditional methods of harvesting molluscs involve the use of hand tools such as tongs and rakes. Mechanical methods using hydraulic or suction dredges (see below) at high tide, or tractor harvesting at low tide, may also be used to harvest molluscs such as clams and cockles.
3.14 Harpoon:
This method is used for fish having high individual value such as swordfish and bluefin tuna. Harpooning is a completely selective fishery, since the target must be seen before striking, so the size and hence age can be determined and only mature fish taken.
3.15 Hydraulic dredges:
Hydraulic dredges either use jets of water to disturb the ground in front of a towed dredge (see above) to capture bivalves, like razorshells and cockles, or use a pump to suck bottom sediments on board ship where bivalves are screened out and the spoil discharged back to sea. Impacts associated with this type of fishing are removal of local populations of the target species, removal and disturbance of sediment with consequences for other species living there, and creation of spoil plumes and siltation.
3.16 Industrial fishing:
Most fishing methods target fish for direct human consumption. Fisheries targeting species for reduction purposes i.e. the manufacture of fish oil and meal, are referred to as industrial fisheries. Fish meal and oil is produced almost exclusively from small, pelagic species, for which there is little or no demand for direct human consumption. The methods of capture are purse-seining and trawling with small mesh nets in the range of 16-32 mm. Important industrial fisheries in South America include the Chilean jack mackerel fishery and the Peruvian fishery for anchoveta. Industrial species in the North Sea and North-East Atlantic include: sandeel, sprat, capelin, blue whiting, Norway pout and horse mackerel. Fish oil is used in a range of products including margarine and biscuits. Fish meal and oil has more widespread use, however, in the manufacture of pelleted feedstuffs for intensively farmed poultry, pigs and, not least, aquaculture.
3.17Long-lining:
Long-lining is one of the most fuel-efficient catching methods. This method is used to capture both demersal and pelagic fishes including swordfish and tuna. It involves setting out a length of line, possibly as much as 50-100 km long, to which short lengths of line, or snoods, carrying baited hooks are attached at intervals. The lines may be set vertically in the water column, or horizontally along the bottom. The size of fish and the species caught is determined by hook size and the type of bait used.
Although a selective method of catching fish, long-lining poses one of the greatest threats to seabirds. Species such as albatross, petrels, shearwaters and fulmars scavenge on baited hooks, get hooked, are dragged underwater and drowned.The problem occurs whilst the baited hooks are on or near the surface i.e. before the hook sinks. Commonly the bait used is squid, the principal prey of many seabird species. Most globally threatened species, including the majestic wandering albatross, live in the Southern Ocean. A range of practical measures have been developed to help prevent seabirds being hooked and drowned on longlines. These include bird-scaring streamers that flap and scare birds away, setting lines at night when most albatross do not feed and weighting the line so it sinks quickly, bird scaring water cannons and setting the line nearer the water surface rather than over the side of the boat,thus minimising the lenght of time the bait is visible/available. Any of these measures will contribute to reducing seabird by-catch. Ask your supplier if the longline caught fish you buy has been caught using "seabird-friendly" methods.
3.18 Pelagic trawl:
When trawling takes place in the water column or in mid-water between the seabed and the surface, it is referred to as mid-water or pelagic trawling. Pelagic trawls target fish swimming, usually in shoals, in the water column i.e. pelagic species. These include seabass, mackerel, Alaska pollack, redfish, herring and pilchards for example. Their effectiveness relies on traversing a considerable volume of water, and consequently nets are larger than bottom trawls and require a large vertical and horizontal mouth opening to provide net stability and capture large shoals of fish. The length of time the net is towed through the water is shorter than in bottom trawling in order to capture the shoals of fish the net passes through. To handle the large amounts of fish, pumps are used to transfer the catch from the cod-end to the boat.
In mid-water pair trawling the otter boards are replaced, and the mouth of the net kept open, by a pair of trawlers. This enables vast nets, often ¼ mile wide and ½ mile long, to be towed through the water column to capture the fish.
Pelagic trawling affects marine mammals as they are caught accidentally when feeding on the same fish being targeted by fishermen; being unable to surface for air they eventually drown. Capture of marine mammals in fishing nets represents a very significant welfare problem. Animals can remain conscious for some time while struggling in the net, causing suffering and injuries such as lacerations and broken teeth and bones, before dying of suffocation. In the UK a Statutory Instrument came into force in December 2004 which bans fishing for bass with pelagic pair trawls within 12 miles of the coast of England in the Western English Channel. Other bass fisheries will be able to continue in the area. The legislation is however unlikely to reduce the amount of dolphins dying in the fishery as the major effort in it is concentrated outside 12 miles. The legislation does not effect vessels pair trawling for species other than bass.
3.19 Pole and line:
Pole and line fishing (also known as bait boat fishing) is used to catch naturally schooling fish which can be attracted to the surface. It is particularly effective for tunas (skipjack and albacore). The method almost always involves the use of live bait (anchovies, sardines etc.) which is thrown over board to attract the target species near the boat (chumming). Poles and lines with barbless hooks are then used to hook the fish and bring them on board. Hydraulically operated rods or automatic angling machines may be used on larger pole and line vessels.
3.20 Pots (or creels):
Pots (or creels) are small baited traps which can be set out and retrieved by the operating vessel. They are widely used on continental shelves in all parts of the world for the capture of many species of crustaceans and fish, together with octopus and shellfish such as whelks. Potting is a highly selective method of fishing, since the catch is brought up alive, and sorting takes place immediately, allowing unwanted animals to be returned to the sea, making the method potentially sustainable. However, in Britain, fishing effort in the potting sector is high, with currently no restrictions on the number and type of pot used or the amount of shellfish taken. Pots used to be constructed from ‘withy’ or willow, but are now constructed from plastic-coated or galvanised wire with nylon netting. This makes them virtually indestructible. Modern pots or ‘parlour pots’ are also more complex and fitted with ‘pot-locks’, making escape impossible for the crab or lobster entering it. These factors combined with mechanical hauling allow fishermen to haul more pots and to leave them on the seabed for longer, thus increasing efficiency and fishing capacity.
3.21 Purse seining:
This is the general name given to the method of encircling a school of fish with a large wall of net. The net is then drawn together underneath the fish (pursed) so that they are completely surrounded. It is one of the most aggressive methods of fishing and aims to capture large, dense shoals of mobile fish such as tuna, mackerel and herring.
Purse seining for yellowfin tuna in the Eastern Tropical Pacific, specifically ‘dolphin-fishing’, where dolphins are deliberately encircled to trap the tuna swimming below them, is probably the most widely reported example of marine mammal by-catch. However, since the introduction of legislation to protect marine mammals in 1972 (Marine Mammal Protection Act) the number of yellowfin tuna taken in nets set deliberately on dolphins now only accounts for a very small proportion (3.3% in 1997) of tuna on the world market.
3.22 Seine netting:
This is a bottom fishing method and is of particular importance in the harvesting of demersal or ground fish including cod, haddock and hake and flat-fish species such as plaice and flounder. The fish are surrounded by warps (rope) laid out on the seabed with a trawl shaped net at mid-length. As the warps are hauled in, the fish are herded into the path of the net and caught. Effectiveness is increased on soft sediment by the sand or mud cloud resulting from the warps’ movement across the seabed. This method of fishing is less fuel-intensive than trawling and produces a high quality catch, as the fish are not bumped along the bottom as with trawling.
3.23 Trap (nets):
Walls or compounds of netting are set out in a particular way and anchored to the seabed so that fish, once they have entered, are prevented from leaving the trap. In some cases, e.g. salmon traps, long leader nets are arranged from the shore to intercept migrating fish and guide them into the trap. Other species taken in traps include bass, herring and tuna.
The selectivity of trap nets is determined by the mesh size used. Undersized or unwanted fish may be returned to the sea alive. However, in many tropical or subtropical fisheries where there is a large mix in species and size range, many fish are likely to become gilled as they attempt to escape from the trap. Seabirds and mammals are also prone to becoming entangled in the nets.
3.24 Use of explosives (dynamite) or poisons (sodium cyanide, bleach):
Dynamite fishing. In some countries such as the Philippines, explosives (dynamite or blast fishing) are used on coral reefs to capture fish. Blast fishing is a particularly destructive method of fishing and is prohibited in many regions. A single explosion can destroy square metres of coral in the immediate area, whilst shock waves can kill fish in a radius of 50m or more from the blast. Reefs in some parts of South East Asia have been reduced to rubble in this way.
3.25 Cyanide poisoning:
Cyanide is used by fishermen in many areas of South East Asia, the Pacific and the Indian Ocean, to stun reef fish such as grouper and Napoleon wrasse which are then exported for the live reef fish food market or aquarium trade. Although its use is prohibited the practice continues because of the demand for certain species (e.g. Napoleon wrasse) as gourmet delicacies
3.26 Trawls:
Trawling is one of the most common methods of fishing in the world. Trawling involves towing one or more trawl nets behind a boat or in between two boats, either through the water column or along the ocean’s floor. Trawl nets are usually shaped like a cone or funnel with a wide opening to catch fish or crustaceans and a narrow closed end called a cod-end. Trawls can be used in water of various depths down to around 3000m, and nets differ by their mesh size.
Demersal trawl
There are two basic types of trawls used in Commonwealth fisheries: demersal trawls and midwater trawls. Demersal trawls are used to catch fish or prawns that live on the bottom of the ocean. Trawlers targeting finfish often use one net (this is called a single trawl) or two nets (twin trawl), whereas prawn trawlers may use a twin-rig (towing two nets) or quad-rig (towing four nets). Both demersal and mid water trawls use otterboards to keep the mouth of the net open.
Midwater trawl :
There are two basic types of trawls used in Commonwealth fisheries: demersal trawls and midwater trawls. Midwater trawls fish in the water column and are used to catch a variety of pelagic fish species. Some fisheries may use paired trawls, where two boats pull one net. Midwater trawl nets may incorporate acoustic technology to tell the skipper the position of the net in the water column, the opening/spread of the net and the volume of fish entering the net. Additional instruments on the net can record the speed at which the net is traveling. Both demersal and midwater trawls use otterboards to keep the mouth of the net open.
3.27 Bottom set gillnet:
Gillnets are long rectangular panels of netting with diamond-shaped mesh that are held vertically in the water column and anchored either so that the net touches the bottom or so it is suspended above the ocean floor. Fish swim into the net and are entangled by the gills, fins and spines. The nets are kept vertical by the floats along the top and weights long the bottom.Only demersal gillnets (touching the ocean’s floor) are permitted in Australia, and are used by one Commonwealth fishery to catch school and gummy sharks.
3.28 Seines:
Seine nets are usually long flat nets like a fence that are used to encircle a school of fish, with the boat driving around the fish in a circle. Purse seine and Danish seine nets are used in Commonwealth fisheries.
Purse seine:
In a purse seine the top of the net is floated at the ocean’s surface and the bottom of the net is held under the water by lead weights. A wire that is threaded through the bottom of the net can be tightened to close the bottom of the net trapping the fish inside. The net is then pulled in toward the boat and the catch is either pumped or lifted out with small nets or the whole net is brought aboard
Danish seine :
Danish seines are similar to a small trawl net but more simply constructed with no otterboards and very long warps – the boat drags the long wire warps and the net around the fish and the action of the warps herd fish towards the central net.
3.29 Longlines :
Longlines are set horizontally either on the ocean floor (demersal longlines) or near the surface of the water (pelagic longlines). Longlines can be tens of kilometres long and carry thousands of hooks. Baited hooks are attached to the longline by short lines called snoods that hang off the mainline.
3.30 Demersal longline :
Demersal longlines are set horizontally on the ocean floor. They can be many kilometres long and carry thousands of hooks. Baited hooks are attached to the longline by short lines called snoods that hang off the mainline. Demersal longlines are anchored to the sea floor.Auto longlining is another type of longlining - it is basically demersal longlining except that some of the functions (for example baiting the hook) are automated.
3.31 Pelagic longline :
Pelagic longlines are set near the surface of the water. Longlines can be many kilometres long and carry thousands of hooks. Baited hooks are attached to the longline by short lines called snoods that hang off the mainline. Pelagic longlines are not anchored and are set to drift near the surface of the ocean with a radio beacon attached so that the vessel can track them to haul in the catch. Pelagic longlines are usually used to catch large tuna and billfish species.
3.32 Dropline:
Droplines are similar to longlines but are set vertically either down underwater cliffs or just in the water column. They have a weight at the bottom, a series of hooks attached to snoods, and a float at the top of the line. They are not usually as long as longlines and don’t have as many hooks.
3.33 Squid jig:
Squid jigging can be carried out using either mechanically powered or hand operated jigs. Overhead lights illuminate the water and attract the squid which gather in the shaded area under the boat. Squid are caught using barbless lures on fishing lines which are jigged up and down in the water. Using barbless lures means that as the lures are recovered over the end rollers, the squid fall off into the boat.
3.34 Dredges:
Towed dredges are used to collect shellfish such as scallops from the sea floor. The dredge used in the Commonwealth scallop fishery is constructed of a heavy steel frame covered with steel mesh but open on the front side which is towed and is used to dig scallops out of the sand and mud. The dredge is towed along the bottom until it is full, then lifted onto the boat and the contents tipped out.
3.35 Traps:
Fish traps are currently permitted in one Commonwealth fishery and some other fisheries are trialing the method. Traps are baited so that fish are enticed to swim into them and are set up with mazes or funnel-shaped entrances so that fish cannot escape once inside the trap
3.36 Turtle Excluder and Bycatch Reduction Device :
Bycatch Reduction Devices (BRDs) are used in trawl fisheries to allow fish that are not targeted by the fishers to escape from the net before it is hauled back into the boat. It is good news for the marine environment as it reduces the amount of bycatch that dies as a result of trawling.
3.37 Seal Excluder Devices (SEDs):
SEDs are very similar to Turtle Excluder Devices (TEDs) but they are designed for use by seals instead of turtles. They are used in the southern demersal trawl fisheries where seals are more likely to be caught.
3.38 Turtle Excluder Devices (TEDs) :
TEDs are used in northern prawn trawl fisheries as an escape hatch for turtles. If turtles cannot escape from a trawl net they cannot reach the surface to breathe and may drown. TEDs consist of a grid across the codend of the net which forces turtles and other large objects out of the net without the prawn catch escaping.
3.39 Other methods and devices :
Minor lines: Minor lines are short lines and only have a small number of hooks, maybe even just one. They include handlines and the rods and reels of the types that are usually used by recreational fishermen. Trolling is when lures or baits are dragged through the water by a slow-moving boat. Poling is another type of minor line fishing. Poles with a bait or lure attached are trolled through the water and when a fish is hooked it is flicked into the boat, rather than being reeled in.
Diving and hand collection:
Some molluscs and crustaceans are collected by picking up, prizing off or digging out by hand. Commonwealth fisheries that use diving and hand collection include trochus, pearl oysters and lobster.
3.40 Maritime Fishing Ground of Bangladesh: Bangladesh has extensive and huge water resources all over the country as small ponds, ditches, lakes, canals, small and large rivers, and estuaries covering about 4.34 million hectares. The culture fisheries include freshwater ponds of 0.15 million ha, and coastal shrimp farms of 0.14 million ha. The country has a coastal area of 2.30 million ha and a coastline of 714 km along the Bay of Bengal, which supports a large artisanal and coastal fisheries. In addition to this, the country has 166,000 km 2 EEZ in the Bay of Bengal. The fisheries sector of Bangladesh is highly diverse in recourse types and species.
Marine fishes are exploited mostly from the Four fishing grounds: Elephant Point(south patches),South of Saint Martin Island, middle ground, and Swatch of no Ground, occupying about 70,000 km area in the Bay of Bengal. Of these the most productive zone is south patches.
Elephant Point.
2100”
2000’’
1900’’
E E Z
1800’’
8900 9000 9100 9200
3.5 Maritime Fishing gear used in Bangladesh:
Fishing Gear any form of equipment, implement, tool or mechanical device used to catch, collect or harvest fish. Fishermen in many parts of Bangladesh catch fish with their hands. In rural areas, in seasonal waters or beels, during winter, people can be usually seen fishing with different traditional gears while some even do so without any gear. The principal categories of fishing gears that are traditionally used in Bangladesh can be enumerated as the following:
Wounding gears Such gears are spears that are thrust, thrown or discharged. The following are the traditional wounding gears: Ek Kata; Tekata I; Tekata II; Anchda; and Koch.
Fishing by poisoning and explosives Sporadic reports have been filed on fishing by poisoning with certain chemicals in some areas of the sundarbans. This practice, however, is not permissible by law.
Line fishing Long lines in both freshwaters and in seawater, use of Bodshi and Charee in angling rods, single lines floated in rural rice fields and beels, etc, are typical line fishing methods used in Bangladesh. In line fishing the fish is usually attracted by a natural or artificial bait.
Traps Different traps made of bamboo sticks are used widely in rural Bangladesh. These are of various shaped chambers essentially having contrivances for the fishes to enter. Escape is prevented by automatic labyrinths or retarding devices. In rural Bangladesh during rainy season when there are floods people use these traps. Different traps seen in different parts of the country are Icber Chai; Bega; Duba Fund; Darkee; Unta; Tepai; Dheal; Cheng; Chari; Chandi Bair; Bana; Polo; Raboni; Anga; and Charo.
Nets On the basis of shape and size, and size of mesh, location of setting in the water, and the way they are used, nets are classified broadly into the following categories:
Bag net- Kept vertically open by a frame and held horizontally stretched by the water current. They can be kept set in water against the water current, as for example Behundi net and Sabadh net, Nets of similar shape but smaller in size are dredged and towed with the hand.
Drag net/push net- These nets are held apart with triangular bamboo frame and pushed manually. They are used in fishing in the traditional waters of beels and floodplains, locally called Thela Jal and Moiya Jal. Trawl nets are also a type of drag net.
Seine net- This type of net has very long wings and a towing rope. The nets are of various lengths and come with or without bags for catching and are locally called Bedh Jal. If the size is too big, it is called Jagot Bedh. The size of the mesh depends upon the size of the fish to be caught.
Cast net- a common net in Bangladesh; it is round-shaped when thrown to fully open and has got weights in the form of iron balls along a string set at the outer edge of the net. It is operated manually and used mainly in the shallows of ponds, beels, estuaries and in the coast.
Lift net- The common shape is square and it is fitted with two bamboo strips arranged in cross-bars and connected at the four corners of the net. The arranged crossbars with the net is then attached with another lever for lifting the net from out of the water. The net is mostly hand-operated and portable. The net is locally called Dharma Jal. Sometimes the size could be made bigger and fixed at some strategic water areas eg Khoda Jal and Konaghar Jal.
Falling net- are of various sizes and shapes depending upon the habitat where they are used and on the type of fish to be caught. A type is mainly seen in northern Bangladesh which is a bigger version of the cast net locally called Othedh Jal. The twine used for this net is heavier and the mesh is also bigger than ordinary mesh. The weights used are heavier too. This net is used to catch fish from the deeps of rivers. About 5-10 people swim and carry the net, spread it out and help it to fall in the desired location of a water body. After setting the net, fishermen wait for hours. Then they start diving in the water to catch the fish. Sometimes they bring fish out of the net or they entangle the fishes with net and leave them there before pulling the net out. Another type of falling net, locally called Chhabi Jal, is used in shallow water; it is made with nylon net and rope. The mouth of this net is held apart with a heavy rope. The net is cone-shaped and the cone is tied with a string. When in use, the net is placed in the water and fishes are trapped inside and get entangled in the net. The other type of falling net is called Chak Jal. It looks almost like the Chhabi Jal. The mouth of this net is tied with a ring of bamboo strip. It is mainly used in rivers and beels during winter months.
Gill net- Commonly seen in rural areas and used in rivers, flood plains and rice fields, Gill net is cast in shallow or deeper waters of rivers or beels. The local name is Fansh Jal. A type of this net, commonly seen in floodplains and rice fields, is locally called Koi Jal because it is generally used to catch koi and some other similar fishes (Anabas testudineus).
Entangling net- a type of gill net used to catch fish by entangling the fish's whole body. The widely talked Current Jal is an example of this type of entangling net. The twine used is of monofilamentous material. The mesh size is variable, however, as the twine is monofilamentous when the fish approaches the net, it can get easily entangled in the net.
3.60 Fishing Craft used in Bangladesh:
Fishing Craft specialized boat, ship or other vessel used for fishing. In freshwaters, estuaries and offshore areas of the bay of bengal commonly used crafts are of various types, sizes, and designs.
Dinginauka Small boats with round bottom. The fore and the hind part of the boat are high above the water level. The stem and the bow are long and pointed. In smaller boats there are no deck but the bigger ones usually possess one. The hood is usually lacking, but when present, is located in the posterior part of the boat. The oars are long and paddle-like. The sail is not carried by most dingis but if present it is made of comparatively thin cloth and is supported by bamboo poles attached diagonally. Fishing dingis are also called Jalia dingis. The dingis are named on the basis of the fishing nets operated by them; for instance, Bhesail Dingi, Patam Dingi, Shangla Dingi, and Talal Dingi.
Chandinauka A traditional fishing boat. The ends are slightly pointed the length varies from 8-12m, beam from 1-3m, and the depth from 75-125 cm. The bottom of the boat is either flat or round. The stem is between 40 and 150 cm. A steering paddle similar to that of an ordinary oar is fixed at the rear of the boat. The hood is situated in the central part of the boat. The sail is often absent but when present is rectangular or square-shaped and placed at the front. The boat is extensively used for Hilsa fishing.
Koshanauka Anterior and posterior ends are blunt, 7-10 m in length and has a flat bottom. Its oars are made of bamboo poles; the deck is made of whole or split bamboo pieces. A hood is never provided. A triangular sail, when present, is situated in the anterior half of the boat. The boat is used for fishing in shallow waters.
Shampan Seen mainly in Chittagong and other coastal districts of Bangladesh. The posterior part is divided into two pointed parts; the bow is pointed and raised above the water. It is used mainly in ferry-crossing of rivers in coastal regions and sometimes for fishing in the estuaries or in the offshore waters of the Bay of Bengal.
Rafts used in almost all the districts of Bangladesh for fishing in shallow waters, they have various local names viz, Bhela, Bhera, Chali, Bhura, etc. Rafts are prepared mainly by fastening together trunks of banana trees. A raft can be 2-3 m in length and 1-1.5 m in width. Clasp nets (Khepla Jal) and Drag nets (Moya Jal) are operated by rafts.
There are also fishing vessels specifically designed and constructed for fishing in the sea. Until the middle of the 20th century, fishing boats were largely based on local designs. Presently, the construction of fishing boat is an international industry and differences in vessel types have more to do with the fishing methods for which they are employed rather than the port of their origin. In modern fishing boat construction, steel is the most material commonly used, although fibreglass and ferrocement are increasingly being used in making boats too. The principal considerations given to the development of fishing boat construction are higher catching power, smaller crews, and reduced operational costs. The Food and Agriculture Organisation has introduced the following classifications of fishing vessels on the basis of the gear used in Bangladesh;
Trawler Vessels with powerful engines and machinery for dragging the trawl nets. Trawlers can be of different types based on the way in which the nets are dragged.
Side trawler Through these trawlers the trawls are launched and pulled at the side of the vessels.
Stern trawler Almost all modern trawlers are of stern types where the trawls are launched and recovered over the stern.
Beam trawler In this type two beam trawls are towed from boom extending to each side and supported by a central mast.
Wet-fish trawler is characterized by the way fish are caught and stored in vessels.
Freezer trawler have freezing facilities; fishes are stored in their freezing chambers when they are at sea for a week or longer.
In Bangladesh sea-going fishing crafts are mainly owned and managed by the Bangladesh Fisheries Development Corporation (BFDC). The corporation has been engaged in fishing in the Bay of Bengal since 1972. It has about 15 medium-sized stern trawlers. The other sea going vessels are boats of different sizes. The majority of the boats are made of wood. The gears used by the fishermen are seine and set bag nets of different sizes
CHAPTER FOUR:
4.1 Findings & Analysis:
It is estimated that about 29% of total fisheries production in Bangladesh comes from seawater. Further 10-15% of total marine production is from the brackish-water region. Total production of fisheries in Bangladesh during 1997-1998 was 1.21 million m ton. Besides, the brackish-water region also supplies roughly 3.0-3.5 billion post-larvae of the Black Tiger Shrimp, Penaeus monodon, annually. Bangladesh produces roughly 50,000 to 60,000 m tons of "head on" brackish-water shrimps annually. It is estimated that 150,000 ha of coastal aquaculture produce approximately 70,000 m tons of mixed fishes, crabs, and small shrimp annually as non-target species.
Brackish-water organisms may be classified into 2 categories resident and migratory. Resident species include mullets, thread fins, saienidaes, perches, Ribbon fish, clupeids, Catfish, Bombay Duck, Camila, etc. Besides, many penaeid shrimps are also resident. Brackish-water aquaculture in Bangladesh however, has not yet developed as a total system dealing with production of finfish and shellfish for domestic consumption and for export maintaining a sound ecological balance.
Marine fisheries collection, commercial exploitation or harvesting of fishes or other products of the sea. World fishery is essentially marine, which occupies more than 97% of the total fisheries; freshwater fisheries constitute only about 2.5%. However, in Bangladesh freshwater fisheries constitute around 70% and marine fisheries including brackish-water occupy the rest. Marine fishing industries though have undergone a period of changes in the past 40 years elsewhere but are still predominantly traditional in Bangladesh. Here during the last 40 years traditional fishing boats got only an engine fixed to gain more mobility. Otherwise, marine fishing essentially remains coastal fishing in Bangladesh where a few species are targeted and which often leads to over exploitation.
Bangladesh has a territorial water of about 20 nautical km from the coast, and again the exclusive economic zone extends about 320 nautical km from the territorial waters. Therefore, the marine fisheries zone of Bangladesh is roughly above 200,000 km2, which is larger than the total area of the country. Marine fisheries can be classified into 2 categories, pelagic, and demersal. Pelagic fisheries of Bangladesh involve mostly plankton eaters, ever-swimming fishes of the upper zone of water. These include Hilsa, Mackerel, POMFRET, RIBBON FISH, Bombay Duck, Indian Salmon, Mullets, Oil Sardine, pelagic sharks, Sword Fish, Butter Fish, Pike, Bonito, Skipjack, Threadfin, Smelts, Indian Anchovy, Dorab Herring, Indian Scad, Bone Fish, etc, and a few other and related fishes which have commercial importance. Dogfish, a smaller variety of shark is also found in Bangladesh water.
Demersal fishes are those which live on the sea floor or near the bottom of seawater. Most of the demersal fishes are either carnivores or detritus feeders. Though the Bay of Bengal has about 442 species of marine fishes, only about 20 species are harvested commercially. Among the demersal fishes Jaw fish, croakers, catfishes, flatfishes, pike, sea breams, snappers, scavengers, eel, goatfish, crabeater, rabbit fish, rock fish, seabass, grouper, silver bream, ribbon fish, and demersal sharks are the most important. On the other hand, roughly 10 species of marine shrimps are included among DEMERSAL FISH, together with some crabs. Though gastropods are considered seafood elsewhere, in Bangladesh these are considered non-edible and hence are not harvested commercially.
Annually 350,000 to 400,000 m tons of marine fish and shrimp are harvested in Bangladesh. Most of the fishes are caught by ordinary fishing boats or mechanized boats and are caught by fixed and drift gill nets, set bag net and long lines.
The Bay of Bengal falls in the sub-tropical zone and no oceanic current enters into this Bay which deprives it in nutrient recycling through upwelling. However, a great volume of freshwater is added to the Bay of Bengal through the combined flow of the Ganges, the Brahmaputra and the Meghna. These rivers carry land washout and a great mass of organic and inorganic nutrients and also help in mixing fresh and marine waters to create one of the world's biggest brackish-water zones. Further, the inflow of a vast amount of freshwater into the Bay of Bengal created one of the world's biggest anadromous fisheries. Hilsa, a marine fish, spends most of its lifetime in the Bay of Bengal then migrates to the river system for spawning. The young individuals return to the sea again. Productivity of the Bay of Bengal partially depends on land washing and freshwater inflow from the landmass.
Marine shrimp fishery In Bangladesh about 1,25,000 hectares of coastal area are now under shrimp cultivation. The four fishing grounds viz South Patches, Middle Ground, Swatch of No Ground and South of South Patches between 10 and 100m depth in the exclusive economic zone (76,800 sq km) of the Bay of Bengal have high fishery potential (stock size of about 30,000-60,000 tons) for capture fisheries. There are about 19 species of shrimps in the marine environment of Bangladesh. Of these, 6 species viz Penaeus merguiensis (Banana Shrimp), P. monodon (Tiger Shrimp), P. indicus (White Shrimp), P. semisulcatus (Green Tiger Shrimp), Metapenaeus monoceros (Brown Shrimp) and M. brevicornis are of commercial importance. The aquaculture production of Penaeus species was about 34,000 m tons in 1995.
The commercial cardigan shrimp Macro brachium Rosenberger though a freshwater shrimp breeds in the estuary of the Bay of Bengal and passes its early life in the estuary. The warm tropical climate, nutrient-rich water with a salinity range from 12 to 39 ppt and oxygen range from 4.0 to 4.8 ppm are favorable for the rapid growth and development of the shrimps. Fleets of small-scale fishing crafts such as traditional boats (about 20,000) and motorized boats (about 12,700), engaged in the continental shelf (66,440 sq km) of Bangladesh, use set bag nets (behundies), trammel nets, beach seines, long lines, gill nets, etc. Shrimps along with fish are caught by these nets at a depth of 10-50 m. In the offshore waters at 10-100m depth commercial shrimping is undertaken in the four fishing grounds by a fleet of about 50 shrimp trawlers. Of the four fishing grounds, the South of South Patches (Southwest of ST MARTIN'S ISLAND) is very important for tiger shrimp.
About six hatcheries are producing fries of giant tiger shrimp for culture purposes. A large number of natural giant tiger shrimp larvae are also caught along the coasts of Cox's Bazar and Khulna with the help of thousands of fine-meshed pushnets, fixed bagnets and dragnets. In such larvae collections of giant tiger shrimp, a large number of larvae of other shrimps and fish are destroyed. Marine shrimp fishery provides a livelihood to thousands of people; the country earns about 270 million US dollars a year from the shrimp export.
Offshore trawler fishery catching fish or harvesting other products at a distance from the shore by using vessels with trawl nets. The trawl nets are used in deep sea fishing in the Bay of Bengal especially in the four fishing grounds about the Bangladesh coast. Commercial trawling with large vessels (21-41m length) commenced around 1978-79. Initially there were only four trawlers, but it increased to about 130 in 1981. By the late 1980s, 31 shrimp trawlers, 10 finfish trawlers and 8 combination trawlers were in operation. At present about 70 trawlers are engaged in offshore fishery.
About 50 species of fish and 15 species of shrimps are recorded in trawl net fisheries in the Bay of Bengal. The principal species caught in the trawl fishery are, among the shrimp, the Brown Shrimp (Metapenaeus monoceros) and Tiger Shrimp (Penaeus monodon). Major contributions to the finfish catches are silver and Black Pomfret (Pampus argenteus and Formio niger), Grunts (Pomadasys spp.), Indian Salmon (Polynemus spp.), Snapper (Lutjanus spp.), Goatfish, Croaker, Mackerel (Rastrelliger spp.), Lizardfish (Saurida spp.) and Hairtails/Ribbon fish (Trichiurus spp.).
Two types of trawl nets are used for fishing in the Bay of Bengal, the Shrimp Trawl Net and Finfish Trawl Net. The shrimp trawl catch includes Brown Shrimp, Tiger Shrimp, Indian White Shrimp and Banana Shrimp; finfish are Tigertooth Croaker, Blotched Croaker, Bombay Duck, Lizardfish, Goatfish and Hilsa shad. The finfish trawl catch includes 20 commercially important species; of these the Indian Salmon, Grouper, Grunt, Pomfret and Ribbon fish show a relatively high proportion even in shallow waters (<30m depth). At the 30-80m depth shrimps and some trash fish are also included in the finfish trawl catches. Smaller penaeid shrimps are caught in relatively high proportions at <30m. The shrimp catch was about 3,000 m tons in 1990; finfish landings were about 7,400 m tons in 1986-87. However, 50-65 percent of the small finfish caught are discarded at sea as trash fish. The standing stock sizes of the Bay of Bengal have been assessed by experts as follows:
Variety Standing stock
(in 000 m tons) Max. annual harvestable stock (in 000 m tons)
Demersal fish 200 – 250 100 – 125
Pelagic fish 160 – 200 30 – 60
Shrimp 30 – 60 2 - 6
Shark fishery collecting or harvesting of members of various orders of cartilaginous fishes belonging to the class Chondrichthyes from the sea as one of the fishery items. In Bangladesh the shark is not a target species in marine fishing; it generally comes as by-catch. Bangladeshi tribal people eat shark meat and fin. At present shark skin is processed for export. Sometimes fishermen collect the powerful jaws, which are sold as ornaments. Sharks are generally caught by gill nets, trammel nets, set bag nets, long line, as well as trawl nets. Total landing of shark could not be estimated as the fishermen generally after cutting their fins throw the carcasses into the sea.
Bangladesh earns a considerable amount of foreign exchange by exporting dried shark fins. In 1994-95, the country exported about 212 m tons of shark fin and fish maws valued about Tk 166 million. Sixteen species of sharks are available in Bangladesh waters. Some sharks enter into the estuaries of southern Bangladesh; these are popularly known as 'Kamot'
4.2 Systems:
Maritime fishing can be categorized into the three types according to the field of fishing. These are as follows;
1) Coastal fishing: Those fishing boat or craft or gears used for fishing near the coastal area along the sea beach are called coastal fishing.
2) Offshore fishing: Those fishing boats or crafts or trawlers that fish within the continental shelf and contiguous area for short period (one, two or three days) are called Offshore fishing
3) Deep sea fishing: Mainly white/finfish and shrimp trawlers are engaged in deep sea fishing. The duration of fishing voyage is from 10 days to 30 days according to their fuel, foods and loading capacity. Normally shrimp trawlers and freezing white fish trawlers fish into the deep sea for more than 20 days. These fishing vessel are engaged in fishing within EEZ of Bangladesh (up to 200 Nautical miles from Base lines).
4.3 Practices:
There are various method and systems are used for fishing in Bangladesh. It depends on many subjects including range of fishing, financial capacity, marketing criteria etc. The following methods are used in Bangladesh for Maritime fishing in the Bay of Bengal
Haaf-Net:
The haaf-net, as used in the Solway, is a framed, bag shaped net which is held against the flow of the tide until a salmon is felt to have entered it. The operator then lifts the net to enclose the fish fully. The beam of the net is typically 5m long with the side sticks about 1m. A net may be fished singly or a group of fishermen may form a row across the current; as the tide floods and the water becomes deeper the fisherman furthest from the shore leaves his position in the line and returns toward shore.
Net and Coble (Beach-Seining):
The only form of netting for salmon ordinarily permitted inside defined estuary limits is known as net and coble, a restricted form of sweep-net or beach-seine. This method may also be used outside estuary limits. A beach-seine (Fig. 33) is a small, single panel surround net consisting of a bag in the middle to hold the catch, a shoulder section at each side and a wing section at each end. The top of the net has a floated headline and the bottom is attached to a lightly weighted solerope. Each wing end is connected by short strops to a danleno stick, weighted at the bottom,
and each danleno is connected to a hauling rope.
Fixed Net:
The set bagnet, a traditionalfishing gear in the Bay of Bengal region, is still being operated by small-scale fisherfolk in Bangladesh.
Set-Nets:
Set-nets are long walls of netting which trap fish either by gilling or entanglement, depending on the size of mesh and the tightness of the netting. The netting is hung on ropes and the hanging ratio can range from a loose 0.3 for tangling fish to a tight 0.6 for gilling. Nets for demersal fish are 1.5 m - 6 m deep and between 50 and 200 m long. The netting is mostly woven from fine nylon twine, which is practically invisible underwater under most conditions. Twine thickness ranges from 0.2 to 0.9 mm. Several types of twine are available and the choice is a compromise between stiffness for ease of handling and softness for catching efficiency. Multi-monofilament twine is commonly used and this consists of 8 to 12 strands of thin monofilament, about 0.15 mm thick, lightly twisted together. Scottish vessels are not permitted to carry monofilament nets under 250 mm mesh size within six miles of the coast. Plastic floats, either ring, cylindrical or egg-shaped, are attached to the headline to keep the netting upright. Floats need to be slightly larger than the mesh opening to prevent them from tangling the netting. Ring floats are convenient as the nets can then be mounted on a solid rod for shooting without snagging. A lead-cored line is attached to the footrope to ensure bottom contact. On large mesh nets for groundfish such as angler (monkfish) and skate that are found tight on the bottom, a polypropylene headline rope without floats provides sufficient uplift. In areas where currents are strong, additional weighting may be added to the solerope. The nets may be used singly or a number joined in fleets with suitable moorings to hold them in place.
Long Lines:
In long line fishing a number of strings each consisting of a main line with baited hooks on branch lines called snoods (Fig. 26), are connected end to end and placed on or just off the seabed with an anchor and dan (marker buoy) at each end. Intermediate dans called ‘tellings’ are used to mark changes in the direction of the long line (Fig. 27). There are two classes of this gear, great lines and small lines. The main difference lies in the sizes of the components.
White Fish Trawler(Pelagic Single-boat Trawling):
Beam Trawling:
Beam trawls are used to harvest whitefish, mainly flatfish such as sole, plaice or megrim together with angler and other species found hard down on the seabed. Each net is fished from an outrigger boom, one on each side of the vessel (Figure 14), and towed from here on a single warp (a) shackled to a three chain bridle (b) attached directly to the beam (c) which holds open the mouth of the trawl. The beam, 9-12 m in length, is constructed from heavy steel tube and supported on each side by rugged steel trawlheads (d) which slide over the sea bottom. Ahead of each groundrope several tons of tickler chains (e) or chain mats (f) are used to disturb fish, causing them to rise up and be taken by the trawl following immediately behind. Towing speeds are generally higher than otter trawling, reaching 6 or 7 knots on clean ground with ticklers, whereas on rough ground stone mats are towed at around 4 knots. Beamers usually operate on the continental shelf (200 m) with warp length/water depth ratios of between 2.5:1 to 3:1. Some larger vessels use a double wire system (z) to facilitate the hauling procedure.
Components of A Modern Trawler:
Fishing Gear/Net.
Trawl doors or otter doors for fishing trawlers.
Fishing Methods for Commercially Important Species – Summary:
1.Demersal Species (Whitefish such as Cod, Haddock, Whiting, Flatfish, etc.)
1) Bottom Trawling (Single-boat)
2) Bottom Trawling (Pair)
3) Seine Netting
4) Pair Seining
5) Beam Trawling
6) Long lining
7) Set-nets
2.Pelagic Species (Herring, Mackerel, Sprat)
(1) Purse Seining
(2) Mid-water Trawling (Pair)
(3) Mid-water Trawling (Single-boat)
3.Shellfish (Nephrops, Shrimps, Scallops, Queens, Lobsters, Crabs, etc.):
1. Bottom Trawling (Single-boat)
2. Scallop Dredging
3. Potting and Creeling
4.Migrating Game Fish (Salmon, Sea trout)
1. Bag-Nets, Stake-Nets
2. Beach-Seining
3. Haaf-Nets
4.4 FIGURE & FACTS:.
MARINE FISHERY RESOURCES:
The Bangladesh coastal zone includes vast estuarine network, coastal plains, tidal flats and islands. This zone provides several natural mangrove forest ecosystem including worlds’ largest compact mangrove area of ‘Sunderban’. The sea water supports more than 400 species of demersal fish, 63 species of pelagic fish, 24 species of shrimps, 5 species of lobster, 13 species of skates and rays, 3 species of cephalopods, 13 species of carangids, 6 species of clupeids, 15 species of crabs, 1 species of green mussels, 3 species of clams, 1 species of sea cucumber and 16 species of sea weeds. The large pelagic fish are still un-exploited, these are tuna and tuna like fishes, large mackerel, sharks and rays etc.
FISHING OPERATION:
a) Number of vessels:
Fish Trawler (BFDC) : 02
Fish Trawler (Private) : 61 (7 newly installed)
Shrimp Trawler (Private) : 45
Trawlers newly approved (Private) : 28 (Fish Trawlers)
Mechanized boat (Private) : 21,830
Non-Mechanized boat (Private) : 28,707
b) Gear-wise Production
Trawler Fishing : 5%
Gill net (mechanized) : 49%
Marine set bag net (MSBN) : 19%
Estuarine set bag net (ESBN) : 10%
Long line : 4%
Trammel net : 2%
Others : 3%
Total = 100%
Fisheries contribution to GDP (at current price) 2003 3.12 per cent
Total Fish Production (2005) (in tonnes) (3) 2,215,957
Capture Fisheries Production (2005) (in tonnes) (3) 1,333,866
Marine capture fisheries production (2005) (in tonnes) (3) 552,096
Freshwater capture fisheries production (2005) (in tonnes) (3) 781,770
Marine (2004-2005)
Industrial 34,114
Artisanal 440,483
Aquaculture (in tonnes) 882,091
Total Fish Exports (Quantity) 2004 (3) 50,948
Total Fish Exports (Value in US$) 2004 (3) 388,210,000
Marine Protected Areas in Bangladesh: 9
4.5 Weather:
Tropical cyclones are usually destructive and affect Bangladesh and its adjoining areas. Tropical storms are called hurricanes in the American continent, typhoons in the Far East and cyclones in the South Asian subcontinent. In the West, hurricanes are identified with human names such as Mitchel, Andrew, Carol, Dorothy and Eve. In the South Asian region no such nomenclature is in use. The term 'cyclone' is at times applied to a mid-latitude depression but is now increasingly restricted to a tropical depression of the hurricane type, especially when it occurs in the indian ocean. A cyclone is called Tufan in Bangla, from the Chinese 'Tai-fun'.
Bangladesh is part of the humid tropics, with the himalayas on the north and the funnel-shaped coast touching the bay of bengal on the south. This peculiar geography of Bangladesh brings not only the life-giving monsoons but also catastrophic cyclones, nor'westers, tornadoes and floods. The Bay of Bengal is an ideal breeding ground for tropical cyclones. Cyclones are usually formed in the deep seas and hence their study has been very difficult. It is only with the advent of the Space age that weather satellites have provided valuable information about them. Direct studies of cyclones with aircraft reconnaissance are also being carried out by advanced countries. However, only a beginning has been made in Bangladesh towards the understanding of cyclones.
Storm surges accompanying cyclones hitting Bangladesh have been noted to be 3m to 9m high. The 1970 cyclone (12-13 November) with a cyclonic surge of 6m to 10m and a wind speed of 222 km/h occurred during high tide causing an appalling natural disaster that claimed 0.5 million human lives. The cyclone of 29 April 1991 hit Chittagong, Cox's Bazar, Barisal, Noakhali, Patuakhali, Barguna and Khulna along with a tidal bore (6.1m to 7.6m), killing 140,000 people.
Cyclones in the Bay of Bengal Because of the funnel shaped coast of the Bay of Bengal, Bangladesh very often becomes the landing ground of cyclones formed in the Bay of Bengal. The Bay cyclones also move towards the eastern coast of India, towards Myanmar and occasionally into Sri Lanka. But they cause the maximum damage when they come into Bangladesh, west bengal and Orissa of India. This is because of the low flat terrain, high density of population and poorly built houses. Most of the damage occur in the coastal regions of Khulna, Patuakhali, Barisal, Noakhali and Chittagong and the offshore islands of Bhola, Hatiya, Sandwip, Manpura, Kutubdia, Maheshkhali, Nijhum Dwip, Urir Char and other newly formed islands.
From 1981 to 1985, 174 severe cyclones (with wind speeds of more than 54 km/hr) formed in the Bay of Bengal. The month-wise occurrence is as follows: 1 in January, 1 in February, 1 in March, 9 in April, 32 in May, 6 in June, 8 in July, 4 in August, 14 in September, 31 in October, 47 in November and 20 in December. It is apparent from the above figures that severe cyclones occur mostly during pre-monsoon (April-May) and post-monsoon (September-December) periods and they are the ones which cause the most destruction.
Chronology of major cyclonic storms :
1970 (12-13 November) The most deadly and devastating cyclonic storm that caused the highest casualty in the history of Bangladesh. Chittagong was battered by hurricane winds. It also hit Barguna, Khepupara, Patuakhali, north of Char Burhanuddin, Char Tazumuddin and south of Maijdi, Haringhata and caused heavy loss of lives and damage to crops and property. Officially the death figure was put at 500,000 but it could be more. A total of 38,000 marine and 77,000 inland fishermen were affected by the cyclone. It was estimated that some 46,000 inland fishermen operating in the cyclone affected region lost their lives. More than 20,000 fishing boats were destroyed; the damage to property and crops was colossal. Over one million cattlehead were reported lost. More than 400,000 houses and 3,500 educational institutions were damaged. The maximum recorded wind speed of the 1970 cyclone was about 222 km/hr and the maximum storm surge height was about 10.6m and the cyclone occurred during high-tide.
1991 (29 April) The Great Cyclone of 1991, crossed the Bangladesh coast during the night. It originated in the Pacific about 6,000 km away and took 20 days to reach the coast of Bangladesh. It had a dimension of more than the size of Bangladesh. The central overcast cloud had a diameter exceeding 600 km. The maximum wind speed observed at Sandwip was 225 km/hr. The wind speeds recorded at different places were as follows: Chittagong 160 km/hr, Khepupara (Kalapara) 180 km/hr, Kutubdia 180 km/hr, Cox's Bazar 185 km/hr, and Bhola 178 km/hr. The maximum wind speed estimated from NOAA-11 satellite picture obtained at 13:38 hours on 29 April was about 240 km/hr. The cyclone was detected as a depression (wind speed not exceeding 62 km/hr) on the 23rd April first in the satellite picture taken at SPARRSO from NOAA-11 and GMS-4 satellites. It turned into a cyclonic storm on 25 April. The cyclone in its initial stage moved slightly northwest and then north. From 28 April it started moving in a north-easterly direction and crossed the Bangladesh coast north of Chittagong port during the night of the 29th April. The cyclone started affecting the coastal islands like Nijhum Dwip, Manpura, Bhola and Sandwip from the evening of that day. The maximum storm surge height during this cyclone was estimated to be about 5 to 8m. The loss of life and property was colossal. The loss of property was estimated at about Tk 60 billion. The death toll was estimated at 150,000; cattlehead killed 70,000.
SIDR: The most recent flooding occurred mid-November 2007. More than 70 per cent of the land area was inundated. It damaged or destroyed over 12 million houses some 27 million people were affected by Cyclone Sidr, the category 4 storm that swept through Bangladesh last week, flattening houses, damaging buildings and roads, and destroying thousands of acres of crops. More than 2,000 people were killed, according to official numbers, and the toll could eventually reach 10,000. But even as Bangladesh begins a massive cleanup operation, many are thankful that it wasn't much worse. As devastating as it was, Sidr has taken far fewer lives than 1991's Cyclone Gorky, which killed at least 138,000 people, and 1970's Bhola, which left as many as 500,000 people dead and is considered the deadliest cyclone, and one of the worst natural disasters, in human history.
4.6 Environment:
Bay of Bengal a northern extended arm of the indian ocean, is located between latitudes 5°N and 22°N and longitudes 80°E and 100°E. It is bounded in the west by the east coasts of Sri Lanka and India, on the north by the deltaic region of the Ganges-Brahmaputra-Meghna river system, and on the east by the Myanmar peninsula extended up to the Andaman-Nicobar ridges. The southern boundary of the Bay is approximately along the line drawn from Dondra Head in the south of Sri Lanka to the north tip of Sumatra. The Bay occupies an area of about 2.2 million sq km and the average depth is 2,600m with a maximum depth of 5,258m. Bangladesh is situated at the head of the Bay of Bengal.
Bottom topography characterised by a broad U-shaped basin with its south opening to the Indian Ocean. A thick uniform abyssal plain occupies almost the entire Bay of Bengal gently sloping southward at an angle of 8°-10°. In many places underwater valleys dissect this plain mass.
Continental Shelf the width of the continental shelf off the coast of Bangladesh varies considerably. It is less than 100 km off the south coast between Hiron Point and the swatch of no ground and more than 250 km off the coast of cox's bazar. sediments are fine seaward and westward with the thickest accumulation of mud near the submarine canyon, the Swatch of no Ground. The shallow part (less than 20m) of the continental shelf off the coast of chittagong and teknaf is covered by sand and the intertidal areas show well-developed sandy beaches. The shallower part of southern continental shelf off the coast of the sundarbans, patuakhali and noakhali is covered by silt and clay; and extensive muddy tidal flats are developed along the shoreline. Some of the shoals and sand ridges present on this part of the continental shelf show an elongation pattern pointed towards the Swatch of no Ground.
Swatch of no Ground also known as Ganga Trough. Swatch of no Ground has a comparatively flat floor 5 to 7 km wide and walls of about 12° inclination. At the edge of the shelf, depths in the trough are about 1,200m. The Swatch of no Ground has a seaward continuation for almost 2,000 km down the Bay of Bengal in the form of fan valleys with levees. The sandbars and ridges near the mouth of the ganges-brahmaputra delta pointing toward the Swatch of no Ground showing sediments are tunnelled through this trough into the deeper part of the Bay of Bengal. The Swatch of no Ground is feeding the Bengal Deep Sea Fan by turbidity currents.
Sunda Trench also known as Java Trench. Running parallel along the west side of the arc of the Nicobar and Andaman islands it is extended northward up to 10°N into the Bay and joins the eastern limit of the Himalayan range. It originated tectonically at the junction of the Indian and Myanmar plates.
Ninety East Ridge major feature of the Indian Ocean which runs in a north-south direction approximately along the longitude 90°E. It lies at the immediate outboard of the Sunda Trench between the Bengal Fan and the Nicobar Fan. The Ninety East Ridge has existed since early in the formation of the Bay of Bengal. The ridge represents the trace of a hot spot formed during the northward flight of India and its associated oceanic lithosphere of the Bay of Bengal.
Eighty-five Ridge a ridge along 85°E longitude. More than 5 km thick sediments have been deposited on either sides of the ridge. The main turbidity current channel of the subaerial drainage pattern lies immediately east of the buried ridge.
Bengal Deep Sea Fan the world's largest submarine fan, also known as Bengal Fan. Together with its eastern lobe, the Nicobar fan, it covers an area of 3106 sq km. It is 2,800 to 3,000 km long, 830 to 1,430 km wide and more than 16 km thick beneath the northern Bay of Bengal. Sediments are tunnelled to the fan via a delta-front trough, the Swatch of no Ground. It can be divided into three parts: upper fan, middle fan and lower fan. Rapid terrigenous sedimentation on an incipient Bengal fan began in the Eocene age (58 to 37 million years ago) as a response to the first intraplate collision and continued to the present, building the world's largest submarine fan.
Geographical characteristics Hydrological conditions surface hydrology of the Bay of Bengal is basically determined by the monsoon winds and to some extent by the hydrological characteristics of the open part of the Indian Ocean. Fresh water from the rivers largely influences the coastal northern part of the Bay. The rivers of Bangladesh discharge the vast amount of 1,222 million cubic metres of fresh water (excluding evaporation, deep percolation losses and evapotranspiration) into the Bay. The temperature, salinity and density of the water of the southern part of the Bay of Bengal is, almost the same as in the open part of the ocean. In the coastal region of the Bay and in the northeastern part of the Andaman Sea where a significant influence of river water is present, the temperature and salinity are seen to be different from the open part of the Bay. The waves and ripples entering from the southern part of the Bay provide the energy for mixing the water and consequently bring uniformity in its chemical and physical properties. Tidal action is also very great in the shallow coastal zones.
Temperature the mean annual temperature of the surface water is about 28°C. The maximum temperature is observed in May (30°C) and the minimum (25°C) in January-February. But the annual variation in temperature is not great, about 2°C in the south and 5°C in the north.
Salinity the surface salinity in the open part of the Bay oscillates from 32% to 34.5% (parts per thousand, ie grams per kilogram of sea water) and in the coastal region varies from 10% to 25%. But at the river mouths, the surface salinity decreases to 5% or even less. The coastal water is significantly diluted throughout the year, although the river water is greatly reduced during winter. Along the coast of the Ganges-Brahmaputra Delta, salinity decreases to 1% during summer and increases up to 15% to 20% in winter. Salinity gradually increases from the coast towards the open part of the Bay. The surface salinity at the mouths of some large rivers like the ganges, brahmaputra, Irrawaddy and some Indian rivers like the Krishna, Godavari, Cauvery and Mahanadi varies widely from one day to another, especially in summer. Salinity of water also changes vertically. The influence of the fresh water is experienced up to depths of 200-300m. From the surface, the salinity gradually increases downward and at about 200-300m it reaches 35% and at about 500m the salinity is more than 35.10%, but at 1,000m it decreases slightly and attains 34.95%. With further increase of depth salinity decreases and at 4,500m it is close to 34.7%.
Tides the semi-diurnal type of tides, ie two high and two low tides during the period of 24 hours and 52 minutes. The highest tide is seen where the influence of bottom relief and the configuration of the coast are prominent, ie in shallow water and in the Bay and estuary. The average height of tidal waves at the coast of Sri Lanka is 0.7m and in the deltaic coast of the Ganges it is 4.71m. In the Bay of Bengal tidal currents specially develop in the mouths of the rivers, like the Hooghly and the meghna.
Colour and water transparency the colour of the water in the open part of the Bay is dark blue which gradually changes to light blue to greenish towards the coast. Transparency is great, 40-50m in some places. In the central part of the Bay of Bengal, the anticyclone circulation is generated and in the centre of this lies the zone of convergence. This region is characterised as a rule by high transparency of water. Regions of low transparency and turbid water are available in the limited area of the pre-deltaic part of the rivers Ganges and Brahmaputra.
Sea Level due to the influence of water density and wind the seasonal changes of the sea level in the Bay are remarkable and one of the highest in the world. The range at Khidirpur is 166 cm, at Kolkata 130 cm and at Chittagong 118 cm. But towards the southwestern coast at Madras and Vishakhapatnam [Vishakhapatnam] the range is small compared to the northern and northeastern coasts of the Bay. The lowest variation of sea level at the southeastern coast of India is due to its geographical location at the edge of a comparatively deep sea.
Ocean Current surface circulation is found to be generally clockwise from January to July and counter-clockwise from August to December, in accordance with the reversible monsoon wind systems. The flow is not constant and depends on the strength and duration of the winds. The effects of a strong wind blowing for a few consecutive days are reflected in the rate of flow. Currents to the northeast generally persist longer and flow at greater speed because of the stronger southwest monsoons. An important vertical circulation in the Bay of Bengal is up-welling. In this process, sub-surface water is brought toward the surface, and conversely a downward displacement is called down-welling or sinking.
Up-welling and down-welling are seasonal, being created by monsoon winds that blow from the southwest during the summer, then reverse direction and come from the northeast during the winter. The persistence of the monsoon, especially from the southwest and the orientation of the coasts cause up-welling to occur along most of the east coast of India. That is why in the east coast of India the up-welling takes place in summer and down welling in winter, and in the eastern part of the Bay of Bengal and in the Myanmar coast, up-welling occurs in winter and the down-welling in summer. However, the duration and intensity of vertical movement of water on both sides of the Bay of Bengal is not as great as on the Somali or North and South American coasts. But it does have a profound effect on the food economy of the sea through its influence on chemical properties and biological populations.
Biological characteristics the occurrence of marine species - both plants and animals - has largely been controlled by the physico-chemical properties of ocean water. Water discharges from the surrounding river catchments carry huge influx of sediments full of nutrients to the Bay, particularly along the near shore region. This has turned the Bay into a fertile marine fishing ground of the region. The near-shore up-welling zone not only has a high yield of nutrients, but also is a high primary production area for the phytoplankton and related zooplankton zones.
Fishing the hydrological conditions of the Bay of Bengal is favourable for a variety of shrimps and fishes. Although fishes remain scattered in the Bay in some places they get concentrated and constitute important fishing grounds. Four fishing grounds have been identified so far. They are south patches, south of south patches, middle ground and Swatch of no Ground.
South patches located at 91.30ºE to 92.10ºE and 20.55ºS to 21.52ºS, having a total area of 3,662 sq km. Depth ranging from 10m to 100m, but 90% of the total area is less than 40m deep. Bottom sediment is sandy or slightly muddy sand. Nearest distance of the ground from Chittagong and Cox's Bazar is 40 km and 10 km respectively. Salinity in surface water ranges from 26% to 32% and 30% to 35% in bottom water. Water temperature varies between 20 and 28ºC.
South of south patches located at 91.30ºE to 92.20ºE and 20.15ºS 20.50ºS, having an area of 2,538 sq km. The nearest boundary of this area is 5 km from Teknaf. Depth ranges from 10m to 100m. Within this ground 75% of the area is more than 40m deep. Bottom is sandy or muddy sand. Surface salinity ranges from 18% to 34% and bottom water salinity from 28% to 38%. Water temperature ranges between 22ºC and 30ºC.
Middle ground located at 90.20ºE to 91.30ºE and 20.25ºS to 21.20ºS, having a total area of about 4,600 sq km. The nearest distance from Cox's Bazar is about 65 km. The depth of 70% of the total area is more than 40m. Bottom sediment is soft mud or muddy sand. Surface salinity ranges from 22% to 34% and bottom salinity 28% to 35%. Water temperature is between 26ºC and 28ºC.
Swatch of no Ground located at 89.35ºE to 90.10ºE and 20.55ºS to 21.55ºS, about 30 km away from Dublarchar and 40 km from Sunarchar. Total area is about 3,800 sq km, of which 70% is more than 40m deep. Overall depth of the area ranges from 10m to 100m. Bottom sediment consists of muddy sand. Surface salinity is 28% to 34%, while the bottom salinity is 30% to 35%. Water temperature falls within 24ºC to 30ºC.
All these fishing grounds are potential reserves for fish and shrimp. Most of the known commercial species of shrimps and fishes are harvested from these areas by trawlers or mechanized fishing boats. Commercially important shrimp and fish species include tiger shrimp, karuma shrimp, cat fish, Bombay duck, snapper, flounder, Indian salmon, crocker, seabream, jawfish, mullet, pomfret, ribbon fish, anchovy, hilsa, oil sardine, tuna, mackerel and skipjack. [Hossain Zamal]
Pollution marine environment of Bangladesh is directly or indirectly becoming polluted due to addition of so many polluting agents. To protect water pollution and control of mine drainage, large scale drilling and production of natural gas from the Sangu offshore gasfield, discovery of Kutubdia offshore gasfield and exploration of beach sand placer deposits from the offshore islands of Chittagong and Cox's Bazar districts must follow standard regulations both from mine safety and environmental protection point of view. Sangu gasfield is located about 50 km southwest of Chittagong City and stands at a depth of 10m water in the Bay of Bengal. Kutubdia gasfield is about 92 km southwest of chittagong port.
The coastal environment of Bangladesh is contaminated by oil tanker traffic, harbour operations and effluents discharged from petroleum processing. sewage disposal by the karnafuli and pasur rivers into the Bay of Bengal contains higher concentration of Biochemical Oxygen Demand (BOD) and foecal coliform. Moreover, the coastal environment of Bangladesh has also been affected by industrial effluents, agricultural residues, some other human activities like deforestation and irrational expansion of coastal shrimp farming, etc resulting in ecological degradation. Overfishing and dumping of discarded fishes in these areas are becoming a threat to the resourcefulness of the fishing grounds. Only proper management of the existing grounds and finding of new fishing grounds can ensure the continuous harvest of fisheries resources
4.7Fisheries education, research & Training :
Education With the increase of population and depletion of fisheries resources due to loss of fish growing land to agriculture, siltation, etc it became necessary to develop an institutional set-up for fisheries education and research. In order to meet the demand for fisheries education and to translate the vast potential of fisheries in Bangladesh into real wealth, the Faculty of Fisheries was established as one of the six faculties of the BANGLADESH AGRICULTURAL UNIVERSITY, Mymensingh in 1967. The faculty of fisheries with its four constituent departments, a fish farm, and a field laboratory, is responsible for training, education and research in various aspects of fisheries. The rationale for setting up the faculty was to produce high quality fisheries graduates equipped with modern knowledge in different fields of fisheries science and to develop the country's fisheries sector through research and dissemination of technology. The Faculty of Fisheries confers the Bachelor's degree, BSc Fisheries (Honours) and has four departments-Fisheries Biology and Genetics, Aquaculture, Fisheries Management, and Fisheries Technology. These departments offer a wide range of courses covering all aspects of fisheries, both basic and applied.
In all the major state run general universities of the country, such as
a. The UNIVERSITY OF DHAKA,
b. UNIVERSITY OF RAJSHAHI,
c. UNIVERSITY OF CHITTAGONG,
d. Shar e-Bangla Agrictural Uiversity,
e. Hazi Danesh Science & Technology University,
f. Patuakhali Science and Technology University,
g. Jamalpur Krishi College and
h. Dhaka Krisi College,
there are zoology departments where a major thrust area is fisheries. Recently, the University of Dhaka has established (1998) a separate department of Aquaculture and Fisheries. Chittagong University has a specialized institute called the Institute of Marine Sciences that emphasizes on marine fisheries. Khulna University has a separate discipline named Fisheries and Marine Resources Technology Discipline.
Research Basic research on fisheries is mainly carried out by the university departments. The Faculty of Fisheries at Bangladesh Agricultural University carries out research in various areas through its four constituent departments. The Department of Fisheries Biology and Genetics focuses on fish fauna, reproductive biology, conservation and management of brood stock, fish breeding, and chromosome and gene manipulation. The Department of Aquaculture deals with fish culture, nutrition and fish pathology; the Department of Fisheries Management offers studies on population dynamics, economics and marketing, biostatistics, and fish health. The Department of Technology deals with processing and preservation, pre- and post-capture technology, fish microbiology and quality of fish products. All the general universities have zoology departments with research programmes at MSc, MPhil, and PhD levels in fisheries subjects.
Applied research on fisheries is carried out in a number of R&D institutions, the foremost of which is the Bangladesh Fisheries Research Institute under the Ministry of Fisheries and Livestock. The Bangladesh Fisheries Research Institute was established in 1984 on the campus of the Bangladesh Agricultural University. The institute has several stations and units such as Freshwater Station on the Bangladesh Agricultural University campus, Riverine Station at Chandpur; Marine Fisheries Technology Station at Cox's Bazar; Brackish-water Station at Khulna; Marine Fisheries Survey and Management Unit at Chittagong; and Marine Fisheries Survey and Management Unit at Cox's Bazar
Training:
Marine Fisheries Academy, Chittagong, Bangladesh:
Marine Fisheries Academy is the only National Professional Institution of Bangladesh established in 1973 for training of personnel for fishing vessel and related industries. With the growing demand and expansion of the fishing fleet, both in Private and Public sectors, the centre was upgraded in 1983 and renamed as “Marine Fisheries Academy”. It is a Government Institution, which offers specialized courses for building a career in the fisheries and maritime industries.
Aim (M.F.A):
The academy educates and trains cadets as per STCW’95F for the deep sea going fishing vessels. Academy also trains cadets for processing plants as per Hazard Analysis and Critical Control Point (HACCP) requirements and also other Maritime Industries. All the Courses are accredited under National University, Gazipur, as Bachelor of Science Courses.
The academy was specially founded to meet the requirements of an acute shortage of Deck and Engineering floating officers and Processing Technologist in the fishing sector.
Training Courses:
The Academy educates and trains cadets for deep sea going fishing trawlers, processing plants and other maritime industries. Cadets are awarded with Bachelor of Marine Science degree certificate for appropriate discipline. The institute provides 3 years training in three branches. They are as follows:
(1) BSC (Pass) Nautical.
(2) BSC (Pass) Engineering.
(3) BSC (Pass) Marine Fisheries.
Cadets graduating from Marine Fisheries Academy are able to find suitable jobs at national and foreign fishing vessels. However, ambitious cadets with seven years experience on the fishing vessels are able to join in sea-going vessel through appropriate examination conducted by the Department of Shipping.
Successfully 1786 cadets graduating from the academy: Branch Year No. of graduated cadets
Nautical 1973-2001 253
Engineering 1973-2001 329
Marine Fisheries 1973-2001 128
Electrical Engineering 1973-1977 15
Radio Engineering 1973-1977 17
Refrigeration Engineering 1973-1979 24
Troll operation 1973-1981 46
Gear Technology 1973-1986 29
Nautical,Engineering and Marine fisheries Techonology 1986-2008 945
Total 1786
Facilities:
1) Administrative Building.
2) Bank, Post office.
3) Residential Cadet Block/Hostel.
4) Play ground.
5) Officer’s residential area.
6) Laboratory facilities:
(a) Marine Engineering.
(b) Marine Fisheries Technology.
(c) Nautical studies.
(d) Marine Fisheries Museum.
(e) Marine Workshop.
7) Maritime Library; Rich in technical collection; the collection is particularly strong in the
field of:
(a) Nautical Studies.
(b) Marine Engineering.
(c) Electronics.
(d) Seamanship.
(e) Gear technology and fisheries technology.
Subjects taught in The Academy.
Academic Subjects:-
a) Physics
b) Mathematics
c) Bio-Chemistry
d) Zoology
e) English
f) General Knowledge and current affairs.
g) Bangladesh Studies.
Nautical Subjects:-
a) Principles of Navigation
b) Coastal Navigation
c) Ocean Navigation
d) Electronic Navigation
e) Radar Navigation
f) Simulated Navigation
g) Marine Operation (Watch-keeping & Communication)
h) Ship Construction
i) Ship Stability
j) Cargo Handling/General Ship Knowledge
k) Meteorology
l) Computer operating & Programming
m) Fire-fighting course
n) First Aid at sea course
o) Basic Survival at Sea course.
Engineering Subjects:-
a) Marine Engineering Knowledge (Motor)
b) Marine Engineering Knowledge (General)
c) Marine Steam Propulsion Plant
d) Marine Gas Turbines
e) Thermodynamics & Heat Transfer
f) Mechanics and Hydro-Mechanics
g) Engineering Drawing
h) Naval Architecture & Ship Construction
i) Electro-technology
j) Workshop, Processes & Materials
k) Workshop Practice/Plant Maintenance.
l) Computer operation & Programming
m) Fie Fighting course
n) First Aid at Sea course.
o) Basic Survival at Sea course.
Marine Fisheries Subjects:-
a) Elements of Marine Fisheries.
b) Coastal Aquaculture
c) Applied Fisheries
d) Fisheries Oceanography
e) Fish processing and Engineering
f) Quality control and HACCP management
g) Fisheries Biology, Environment Assessment.
h) Fishing Gear & Methods
i) Seamanship
j) Signals
k) Computer operation & Programming
l) Fire Fighting course
m) First Aid Course
n) Basis Survival at Sea course.
CHAPTER FIVE: PROBLEMS & RECOMMENDATIONS:
5.1 Problems:
The following constraints to be addressed to increase the marine production in a
sustainable manner by reducing capture in the sea which will have tremendous and long-term impact on livelihoods of the coastal people and, where the regional cooperation will be essential to lessen the constraints:
a. Lack of awareness about Mariculture like cage culture
b. Lack of appropriate technology for Mariculture which will be best fit in
Bangladesh
c. Inadequate infrastructures in relation to information & communication,
transportation, hatcheries for seeds, market, etc
d. Lack of skill human resources in this field
e. The areas for Mariculture not yet demarcated by the government
f. Lack of finance to the sector
The human–resource relationships that operate at present in the coastal zones of Bangladeshare characterised by an insecurity that tend towards destabilisation of the capabilities, assets and activities that make up the livelihood system of individuals, families, households and the wider community. Specific features include:
1. Widespread poverty, limited livelihood opportunities (especially outside agriculture) and poorly developed economic linkages, including poor access to national and international markets that are even more severe than in other parts of rural Bangladesh.
2. Poor levels of service provision and very poorly developed institutional structure (with both government and non-government institutions weakly represented in many coastal communities) that make the isolation of many coastal areas worse.
3. Highly unequal social structures, with a small powerful elite dominating the mass of people, allied to high levels of conflict and poor law and order.
4. Rapid decline in key common property resources such as marine fisheries, mangroves and freshwater resources.
5. The threat of cyclones and storm surges is a constant feature of life, with devastating events such as the 1970 and 1991 cyclones and smaller storms every year.
6. The long-term effects of climate change, with predicted rises in sea levels, possible
7. increases in the frequency of major storms and changes in rainfall patterns over the whole Ganges-Brahmaputra basins.
8. Active processes of land erosion and accretion in the Meghna Estuary combined withgeological and tectonic processes that are causing land to sink.
9. Changing patterns of land use, both in the coastal zone (including the growth of shrimp and salt production) and over the catchment as a whole that are affecting the coast’s morphology and water resources characteristics.
10. Declining viability of many distinctive and threatened coastal ecosystems, including the Sundarbans and other mangroves, coastal wetlands and marshes, and offshore marine habitats that are important spawning grounds.
11. Widespread pollution and resource degradation, including ‘hotspots’ such as the coast north of Chittagong as well as areas affected by more widespread processes.
12. Poor access to many forms of infrastructure and technologies and many examples of technical interventions that are poorly adapted to the characteristics of coastal areas.
13. Surface and sub-surface salinisation, including saline intrusion into freshwater aquifers some distance from the coast.
14. Poor resource management, including the unsustainable exploitation of fish resources and poor ground and surface water management.
15. Make estuary for marine resources
16. Ensure awareness, educations and training to the fisherman.
17. Control of industrial pollutions.
18. Control of marine pollution.
19. Prevent fishing during fish breeding season.
20. Prohibit fishing near the coastal zone( Below 40 Meter dept contoure)
21. Follow the The National Legislations like Marine fisheries Ordinance 1983, Marine fisheries Rules 1983, Protection and conservation ordinance 1982, Protection and conservation of fish rule 1985 etc.
22. Continuous monitoring on fish hunting in the sea.
5.2 Recommendations:
First, the management information system for the fisheries sector should be improved in order to dynamically assess the state of the sector, and the costs and benefits resulting from adjustments in fishing capacity. The marine data collection and research cell should be strengthened to provide the government with the necessary information to manage and optimize catch from trawl as well as inshore fishing.
Second, the management of the fisheries sector should be informed by an integrated approach that takes into account the economic, environmental and social factors affecting fish supply, fish stock and fishing capacity. For example, prior to any initiative to increase productivity through modernization of the sector, it should first be understood what integrated impacts might result, such as environmental degradation and employment loss.
Third, given the sector’s low level of development and lack of any effective guiding mechanism, there is a case for time-limited government support to promote the sector’s sustainable management. This could be in the form of developing supportive marine sector infrastructure, such as port and docking facilities, cold storage facilities, or repair and maintenance services. Additionally, in order to avoid overfishing in the long-run Bangladesh should review regularly the state of its fish stocks. Procurement, processing and marketing support programmes for the small and marginal fishermen involved in marine fishing could also help reduce rent-seeking behaviour within the market. The country should also encourage dissemination of improved fishing practices to minimize by-catch, waste and discard. To this end, investment should also be directed to necessary trade-supportive infrastructure.
Fourth, Bangladesh needs to strengthen its monitoring, control and surveillance capacity in its territorial water with a view to stopping illegal, unregulated and under-reported fishing as these affect sustainability.
Fifth, the sustainable exploitation of fishery resources can only be ensured through close regional cooperation since fisheries resources, in essence, are ‘regional commons’ among neighboring countries. The design of a regional strategy to exploit the common marine resources of the Bay of Bengal could be helpful in this regard.
1. Small-scale fisheries contribute about 95% of the total fish harvested from the marine water. Privilege will be given to the small-scale fisher folk communities in the coastal areas for fishing.
2. Fishing in the coastal areas will be conserved for small-scale fisheries sector. Areas will be demarcated for small- scale and large-scale fishing determined from results of research, surveys and information of commercial harvest and regulated by updated laws. The conservation of coastal and deep-water marine resources will be considered with importance on the basis of research results.
3. Research and surveys will be conducted under regional and international programmers to develop capacity for using modern fish harvest techniques. ,
4. Special emphasis will be given to secure the life and resources of the fishers’ communities to improve their socio-economic condition. For this reason, the following programmers will be undertaken
I. Life and property such as boat, engine, nets, fish, etc. of the fisherman shall
II. be protected by insurance policies.
III. b) Each fishing-boat must keep life saving equipment and radio on board.
IV. c) Necessary measures will be taken to stop piracy at sea.
V. d) To increase working efficiency and family income of the fisher community members, appropriate
VI. training programmers will be developed on the new and modem fish harvest techniques, fish
VII. conservation, distribution, processing and preservation.
VIII. e) Supervised credit system will be developed instead of the present security based credit system.
IX. f) Infrastructure facilities of the coastal fisheries landing centres will be developed to reduce the
X. Spoilage of fish harvested by the poor fishermen and also to ensure a fair price for their catch.
XI. g) Prior permission will be required from the Ministry of Fisheries and Livestock for the construction
XII. of fish landing centers and establishment of retail fish markets by the private sector.
XIII. Make estuary for marine resources
XIV. Ensure awareness, educations and training to the fisherman.
XV. Control of industrial pollutions.
XVI. Control of marine pollution.
XVII. Prevent fishing during fish breeding season.
XVIII. Prohibit fishing near the coastal zone( Below 40 Meter dept contoure)
XIX. Follow the The National Legislations like Marine fisheries Ordinance 1983, Marine fisheries Rules 1983, Protection and conservation ordinance 1982, Protection and conservation of fish rule 1985 etc.
XX. Continuous monitoring on fish hunting in the sea.
Protection & Prevention from Cyclone:
Weather satellites in cyclone warning Bangladesh does not have satellite facilities of its own, but with the help of ground stations, it receives weather pictures from weather satellites launched by advanced countries. An APT (Automatic Picture Transmission) Ground Station for the reception of imagery from weather satellites was established in 1968 in Bangladesh (then East Pakistan). Recently SPARRSO has established advanced receiving and analysing equipment with financial assistance from USAID under NASA's supervision. With the help of this equipment both low and high-resolution data from American NOAA-14 and NOAA-15 and Japanese GMS-5 satellites are received. The GMS satellites transmit data every hour. Data from NOAA satellites are obtained every six hours. An automatic grid, ie latitude, longitude and national boundaries are fitted in the picture with the help of the present equipment. Because of this equipment, no cyclone in the Bay of Bengal can escape notice.
Prevention The energy in a severe cyclone is equivalent to that of several thousand atom bombs of megaton strength and hence it is difficult even at this advanced stage of technology to try to modify a tropical cyclone. The United States has conducted experiments in the Atlantic by spraying silver iodide in the region of the maximum wind speed to minimize the wind speed. These experiments, though very promising, have remained inconclusive. Moreover, there is a chance that these cyclones could change their track and move towards another direction. Other methods which have been suggested for preventing the formation or reducing the severity of tropical cyclones is to cover the probable area of sea surface with a thin layer of oil or some chemical substance for reducing evaporation. However, the pollution effect of this gigantic effort needs to be considered before this experiment could be carried out.
Protection Cyclone is a natural phenomenon like an earthquake or a volcanic eruption. Countries like Bangladesh have to learn to live with it. By strengthening the cyclone warning system and adopting protective and relief measures, the damage could be minimized. Bangladesh today has a comprehensive Cyclone Preparedness Programmed (CPP) jointly operated by the Bangladesh Red Crescent Society and the Ministry of Disaster Management and Relief. It has a membership of about 32,000 devoted volunteers spread over 2,043 wards of 195 unions of the coastal belt of Bangladesh. In each ward the trained volunteers are ready to do the needful in the event of a cyclone. Each ward is provided with a transistor radio, a megaphone-cum-siren, a signal torchlight and first aid kit. Almost every upazila is provided with a wireless set, which keeps direct communication with Dhaka.
The entire government machinery including the army, the navy, the air force and the relevant ministries and organizations are required to discharge their duties in the event of a cyclone. There is a standing order pertaining to cyclones, which lay down actions by all during the various stages of the disaster.
Cyclone warning and preparedness measures have improved in Bangladesh in recent years. This has been amply demonstrated during the catastrophic cyclone that struck Bangladesh in 1997. Some 2,500 cyclone shelters have been built and a coastal greenbelt project for forestation of the coastal areas is also in progress. The improved cyclone warning system and mobilization of people before the impending cyclones have been very effective in minimizing the death toll.
6 Conclusions:
The marine fisheries sector is a source of employment and income for a large sector of the population, particularly in rural areas. According to the Ministry of Fisheries and Livestock (MOFL), employment in this sector has increased from 123,562 in 1984 to 916,539 in 1999, implying that the annual growth of employment was 14.3 per cent during 1984-1999 (GOB, 2001a). So, Proper Fish harvesting policy and service rules are to be made by the government for smooth management of for the employees of fishing sector. Bangladesh is sandwiched between India and Myanmar in the upper reaches of the bay and says survey ships and even naval ships of the two countries cross into what it considers to be its own territory. Illegal entrance of foreign trawlers and navy ships especially Indian Navy ship has become most severe problem for the Bangladeshi Fisherman as they opposed to fish in the Bangladeshi legal Maritime area. So Government has to take initiative to solve the Maritime Boundary problem according to UNCLOS unless Bangladesh will loose her Maritime area day by day like South Talpotti.
6.0 References :
1. Annual Survey Data from Bangladesh Marine fisheries dept. Chittagong.
2. Fisheries Resources Survey System, Department of Fisheries, Government
of Bangladesh.
3. “Report on the Management of Marine Fisheries”, Department of Fisheries,
4. Ministry of Fisheries and Livestock, Government of Bangladesh (GOB), Dhaka.
5. 2001b. Brief on Department of Fisheries, Ministry of Fisheries and Livestock,
Government of Bangladesh (GOB), Dhaka.
6. Khatun Fahmida. 2004. Fish Trade Liberalisation in Bangladesh: Implications of SPS
7. Measures and Eco-Labeling for the Export-Oriented Shrimp Sector, FAO.
8. Schaefer, M. 1957. “Some Considerations of Population Dynamics and Economics in Relation to the Management of Commercial Marine Fisheries”, Journal of Fisheries Research, Board of Canada, No. 14, p 669-81.
9. “Some Aspect of the Dynamics of Population Important to the Management
10. of the Commercial Marine Fisheries”, Inter American Tropical Tuna .
11. Nurul Kareem A.N.M. (October 2002) Fish Marketing System from Coastal
12. Areas of Bangladesh, University of Chittagong;
13. Rahman, Mirza Md. Shafiqur, et al, August 1997: “Report on Participatory
Rural Appraisal in Two Coastal Fishing Villages”, Study commissioned by
FAO Representation, Dhaka.
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