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Study of fishing gear selectivity of Chanda beel, a floodplain in Bangladesh.

Introduction

Floodplains, which are seasonal and may or may not have beels or low-lying depressed area carrying some perennial water, spread over almost all over the country. The floodplains are also used, as the seasonal abode, by a large number of fish, prawn, turtle, mussel and other aquatic animals. Of these, fish and prawn are the most important aquatic living resources essential for the people residing in an around floodplains (Alam et al., 1997). But in recent years the fish production of floodplains has decreased (DOF, 1995). Yadava and Sugunan (1992) stated that, the beel (floodplain) was subjected to indiscriminate fishing throughout the year. So regular stocking of Indian and exotic carps would necessitate a well planned fish capture schedule and deployment of optimum effort. This would also entail strict enforcement of mesh size, besides a calendar of fishing practices to be employed in different times of the year by the fishermen. In order to arrest the continuous decline in fish production in floodplains, government had undertaken a massive pilot stocking program with credit from the World Bank under Third Fisheries Project (TFP) which included Chanda beel (Figure 1) in Gopalgonj (DOF, 1990). Local and Chinese carp fingerlings were stocked in Chanda beel, in July 1992. Bangladesh Fisheries Research Institute (BFRI) had been associated with the TFP to support its research activities in the floodplains. Safeguarding the early growth stage of stocked fingerlings from exploitation is one of the key elements for the success of any stocking program. BFRI had, therefore, initiated gear selectivity study research in connection with the implementation of TFP project with the following objectives: 1) to describe types and characteristics of fishing gear used in the floodplains, 2) to determine their species and size (length) selectivity, and 3) to recommend fishing gear regulation, that protect the stocked fingerlings from exploitation. This gear selectivity study started in late June 1992. The results obtained during the monsoon season from June to October 1992 are summarized here.

No gear selectivity study on floodplains fishery has been under taken in Bangladesh before and published paper on this subject is also very scanty. However, many researchers have studied gear selectivity abroad. For example, Siddeek (1986) reported his mesh selectivity and biological impact studies on a new fish-cum-shrimp trawl in Palk Bay and El Musa (1982) published the mesh selectivity study in Kuwait. The "covered cod end method" has been described, among others, by Pope et al. (1975) and Jones (1976). According to Sparre and Venema (1992) most fishing gear, for example trawl gears, are selective for the larger sizes, while some gears (gill net) are selective for a certain length range only, thus excluding the capture of very small and very large fish. This property of fishing gear is called "gear selectivity".

[FIGURE 1 OMITTED]

Materials and Methods

For this study, a monthly data collection program was conducted at fish landing centers (para and bazar) and at fishing grounds. Fishermen who came to the centers with fishing gear were sampled for gear information and catch data collection. From cast net and push net, of which catches were rarely landed at the centers, the data were collected in the fishing grounds.

For each type of fishing, the gear characteristics (mesh size, length, width, structure etc.) were observed. The fishing practices (location and time of fishing, and fishing method) were observed in the field. The catches were sorted into species and total lengths of individual fish were measured in mm. For each type of gear, a number of collections (collection is the number of catches of a fishing unit with a type of gear) were made to obtain the desired size of sample population (the number of fish those have been measured), i.e. at least 250 fish for a dominant species in a given gear. But in certain cases, less then 250 fish were considered as dominant species due to their less availability.

Data analysis

For each type of gear, the species composition of the catches was studied to determine the species selectivity. To estimate size (length) selectivity of the species caught in gear, the [L.sub.50%] value and selection range ([L.sub.25%] - [L.sub.75%]) were calculated for each dominant species with the help of probit and linear regression. The [L.sub.50%] is the length at which 50% of the fish entering the gear are retained and 50% escape. It is also called "length at first capture". The selection range is the range of lengths between [L.sub.25%] (the length at which 25% of fish entering the gear are retained) and [L.sub.75%] (the length at which 75% of fish entering the gear are retained). The 50% retention length and the selection ranges (25% and 75%) were evaluated according to Pope et al. (1975).

The following procedures were followed to estimate [L.sub.50%] and selection range in each month

The range of lengths of the sampled population was divided in to about 9 to 13 length intervals, depending on the sample size. According to the intervals, the normal frequencies were established. The normal frequency were transformed to cumulative frequencies, and then to percentage (relative) cumulative frequencies. The percentage cumulative frequencies were then transformed to probits by using Table 1 Transformation of percentage to probit from the book of "Statistical Tables for Biological, Agricultural and Medical research" written by Professor R. A. Fisher and Dr. Yatos. A linear regression analysis was conducted between the length intervals (independent variable) and the probits (dependent variables). Using the length-probit regression equation, the lengths at probits of 4.32, 5.00 and 5.67 which correspond, respectively to 25%, 50% and 75% of the percentage cumulative frequencies were calculated as [L.sub.25%], [L.sub.50%] and [L.sub.75%].

Results and Discussion

During June to October, 1992 (monsoon season), a total of 125 collections (catches) were examined in Chanda beel. The fishermen use 17 types of fishing gear (Table 1 and Figure 2). The gears were classified into four groups; 1) fish net, 2) fish trap, 3) Hook and line and 4) Spear/ Harpoon.

According to Choudhury (1989), two categories of nets are mainly used for fishing in the beels I) Moving nets and ii) Stationary nets. The moving net was divided into three types: drag nets, dip nets, and cast nets. He also classified stationary nets into gill nets, hook and line, traps, katal fishing, bana fishing, and dewatering. A total of 40 species of fish were identified in the catches of different gears used by the fishermen in Chanda beel. The local name, common name, scientific name and family name of each species are shown in Table 2 and Figure 2.

Data of the above 17 types of gear were analyzed and the results described below:

Gill Net (Local name: Puti jal/ koi jal):

Material and structure

The gill net is made of monofilament nylon twine or double cotton twines, rectangular in shape, 45 -70 m long and 0.9 m wide. Usually floats are put on the upper edge of the net and weights on the lower edge. There are three mesh sizes; 2.54, 3.18 and 3.81 cm.

Fishing operation

The net is usually set near surface water or mid water along the edge of aman paddy fields or of areas infested with water hyacinth or rooted vegetation. It is set in the evening and harvested in the morning or viseversa. The gill net is the primary fishing gear in Chanda beel during the monsoon season.

Species selectivity

A total of 69 collections were examined. Table 3 shows the species and number in the catches of gill net. Twenty species of fish were found in the gill nets catches of the three mesh sizes. Almost all were the floodplain resident species, which begins breeding at the onset of inundation and grows during the monsoon flood season. Puti Puntius stigma, kholisha Colisa fasciata, shing Heteropneustes fossilis koi Anabas testudineus, tengra Mystus vittatus, taki Channa punctatus and baila Glossogobius giuris were dominant species while bheda Nandus nandus, baim, Mastacembelus armatus shoal Channa striata, magur Clarias batrachus, kakila, Xenentodon cancila were common. Pabda Ompok pabda, chanda Ambassis nama, tatkini/ raikhor Cirrhina reba, pholi Notopterus notopterus, gutum Lepidocepalus guntia, boal Wallago attu, boicha Colisa channa and darkina Esomus danricus were the minor species.

There was apparently a seasonal shift in the use of three different mesh sizes. The 2.54 cm mesh net was commonly used in June/ July (beginning of monsoon season), the 3.18 cm mesh from June to August and the 3.81 cm mesh net from August to September. The seasonal shift in mesh size from small to large from June to September corresponded to the growth of the target species. Also, there were more species caught by 2.54 cm and 3.18 cm mesh net in June/ July and August than in September, whereas the 3.81 cm mesh net caught more species in August and September than June/July.

[FIGURE 2 OMITTED]

Stocked carps were not found in the catches of gill nets. Fishermen also informed that gill nets (koi jal /puti jal) did not allow carp fingerlings to be caught. Apparently, the location and way of setting of net do not catch carp fingerlings, or the fish might be able to avoid the nets. According to Sparre and Venema (1992), gill net is "passive gears" i.e., the fish has to swim into the net to get caught. This implies that fish which moves fast, has a larger probability of encounter with the gear than slow moving fish. It is known that large fish move faster than small fish of the same species.

Length selectivity

Table 4 shows the monthly [L.sub.50%] values and selectivity ranges ([L.sub.25%]- [L.sub.75%]) of dominant species. Puti Puntius stigma, kholisha Colisa fasciata, shing Heteropneustes fossilis, taki Channa punctatus, tengra Mystus vittatus, koi Anabas testudineus and baila Glossogobius giuris were caught by gill nets of three different mesh sizes from June to October. Puti Puntius stigma a small fish, the [L.sub.50%] values during the four month's period ranged between 7.66-7.92 cm for the 2.54 cm mesh net, between 7.10-8.06 cm for the 3.18 cm mesh and between 8.07- 9.61 cm for the 3.81 cm mesh net. The [L.sub.50%] values increased as mesh size increased, but only for August, September and October. There was no difference in the [L.sub.50%] values from June/ July to October for the 2.54 cm mesh net. This may suggest that puti Puntius stigma has a long spawning season to sustain continuous supply of recruits of same size ([L.sub.50%] from 7.66-7.92 cm) for 2.54 cm mesh net fishery during the monsoon season. No fish was caught by 3.81 cm mesh net in June/ July, indicating that mesh size was too large to catch this species in the early monsoon, when the fish was small. The selection of larger fish by larger mesh sizes were obvious in September and October and less so or absent in June/ July and August. The above differences in the size selection among the three meshes sizes and among months were for the change in the size composition of the fish population due to the continuous recruitment and growth of fish.

Kholisha Colisa fasciata is another small annual fish. The [L.sub.50%] values ranged between 6.44- 8.57 cm for the 2.54 cm mesh net, between 6.46-8.19 cm for the 3.18 cm mesh and 7.96- 8.57 cm for the 3.81 cm mesh net. The [L.sub.50%] increased as the mesh size increased in of August and September. It also increased from August to October for the 2.54 cm mesh net and from June/July to October for the 3.18 cm mesh and from August to September for the 3.81 cm mesh net. Very few fish were caught by 3.81 cm mesh net in June/July. There was a similar pattern in changes of [L.sub.50%] among the three mesh size nets and among the months for kholisha Colisa fasciata and puti. Puntius stigma These two small annual floodplain resident species perhaps with very similar life-cycle well corresponding to the hydrologic cycle. Similarly was observed in case of shing, Heteropneustes fossilis koi Anabas testudineus, taki, Channa punctatus and baila Glossogobius giuris.

Cast Net (Local name: Jhaki jal/ khepla jal):

Materials and structure

The cast net is circular net with a radius of about 3.7 m. It is usually made of cotton twines with weights around its edge. The center of the net has a rope of about 9.1 m. It has four different mesh size; 1.0, 1.5, 2.0 and 2.5 cm.

Fishing operation

Fisherman ties the rope on one of his wrists and holds the net on his opposite shoulder and arm in a way that when the net is cast, it opens into a circular shape and falls on the water surface. Thereafter, the net reaches the bottom, and then fisherman pulls it up to shore to pick up the fish caught. Uually, the net is cast from river bank or fishing boat. It is commonly used in khal (canal), where water is clear of water hyacinth or submerged rooted vegetation. Because the fishing is more effective in shallow water, the cast net fishing are practiced more intensively in Chanda beel during the water ascending season (June/July) and receding season (October onwards).

Species selectivity

Twenty five collections were examined in the fishing grounds. A total of 18 species of fin fish and prawns were found in the cast net catches of four different mesh sizes (Table 5). Of them, prawns were most dominant. The dominant fin fish species were variousmall species such as puti Puntius stigma, baila, Glossogobius giuris kholisha Colisa fasciata cancila a, chanda Ambassis nama and tengra Mystus vittatus. Minor species were taki Channa punctatus, baim Mastacembelus armatus, boal Wallago attu, mola Amblypharyngodon mola, gutum Lepidocepalus guntia, khorsola Rhinomugil corsula, kakila Xenentodon cancila, banshpata Danio devario, dhela Rohtee cotio, ghunia Labeo gonius, buguri, Mystus tengra cheng Channa gachua and gaura tengra Leiocassis rama. Major carps and common carps were not found in the catches. The fishing grounds of cast net in the Chanda beel were located primarily in big canal near inlets and outlets of the beel. It seems that it is not an effective gear for carps in Chanda beel.

Length selectivity

Thirteen samples were used for estimating [L.sub.50%] and selective range for five dominant species chanda A.nama., baila G. giuris puti P. stigma, kholisha C. fasciata.and tengra M. vittatus. Their [L.sub.50%] values and selective ranges are shown in Table 6. The [L.sub.50%] value of chanda A. nama was 5.28 cm for the 1.0 cm mesh cast net, 5.99 cm for 1.5 cm mesh and 6.17 cm for 2.0 cm mesh net. The value increased as the mesh size increased which was seen for baila G. guris, kholisha C. fasciata , and puti P. stigma too. Also, as compared to the [L.sub.50%] obtained by the gill net, the values of baila G. giuris , puti P. stigma and kholisha C. fasciata caught by cast nets were much smaller than those caught by gill nets, due to the much smaller mesh sizes of cast nets (Tables 4 and 6).

Seine Net (Local Name: Ber jal):

Material and structure

Seine net is rectangular in shape, 61-91 m long and 1.5 m wide, made of cotton twines with floats on the upper edge and weights on the lower edge. Its mesh size varies from 0.5 to 2.54 cm.

Fishing operation

The net is usually operated by a team of fishermen in shallow water area of beel proper where aquatic vegetation is scarce. The net surrounds the area and the vegetation inside is then cleared. Some water hyacinths are often kept on one side of the net as shelter for the fish. The fishermen pull the other side of net towards water hyacinth to reduce the surrounding area. When the area becomes small enough, water hyacinth is removed and lower edge of the net is pulled up to catch fish. The fishery is usually operated during the water ascending season and receding season, when the water level in the beel proper is low.

Species selectivity

The seine net is more or less a species non-selective gear. The species and size composition in catches depends on fish species that are present while fishing, and thus they differ in location, time and season.

Only five collections were obtained in September and October. Puti Puntius stigma, chanda Ambassis nama, bheda Nandus nandus, banshpata Danio devario and kholisha C. fasciata and gutum Lepidocepalus guntia were the collections in October (Table 7). Rui Labeo rohita, catla Catla catla, and mrigal Cirrhina mrigala were present in the above months, and common carp was found in September and silver carp Hypophthalmichthys molitrix in October. The carps contributed 4.9% in September and 13.42% in October of the total number of fish in the catches. Due to drought, water quality deteriorated badly in the beel in these two months, particularly in the areas heavily infested by water hyacinths, rooted vegetation and aman paddy. In these areas dissolved oxygen (DO) contents at the depth of 1.5 m in the day time were often less than 2 ppm. Less than 1.0 ppm DO was recorded in heavily infested water hyacinth area (FRI, 1992). It is suspected that in the night, DO might drop down further to reach zero ppm in most part of the beel. Hence the carps in the beel gathered to open area (less vegetation) where DO was comparatively high, resulting in higher catches of carps in the seine fishery. Also, the mode of operation of this gear destroys the normal habitat of resident species possibly of stocked carp as well.

Length selectivity

For the dominant small fish, the [L.sub.50%] value and selectivity range ([L.sub.25%] - [L.sub.75%]) were 5.0 cm (4.32 cm - 5.67 cm) for kholisha C. fasciata. in October, and 17.74 cm (12.29 cm - 23.17 cm) for kakila X. cancila , 6.31 cm (5.79 cm - 6.83 cm) for chanda A. nama. and 12.05 cm (10.78 cm -13.32 cm) for baim M. armatus in September (Table 7).

Because of few collections the sample sizes of carps in catches were insufficient to estimate [L.sub.50%] and selection range. The total length ranged between 16.0-29.0 cm for catla C. catla and 18.0-32.0 cm for silver carp H. molitrix in October.

Lift Net (Local name: Veshal jal/ khora jal):

Material and structure

Lift net is a type of fixed gear. It consists of two parts bamboo frame and net. The bamboo frame is triangular in shape. Its two arms are bamboo poles where the net is tighten. The frame is fixed on the bottom by several vertical bamboo poles. The net, made of cotton twines is also triangular in shape. It is about 9.0 m long on each side. Its mesh size usually differs in different parts of the net. It is 0.5- 1.0 cm in the central portion, 2.0- 2.5 cm near the two arms, and 1.0- 1.5 cm at the front side of the net.

Fishing operation

Lift net is usually used in canal in an area that is free from water hyacinth. The front edge of net is faced against water flow. The net is lowered into water keeping on the bottom for a few minutes, and then pulled it up by the weight of fisherman who stands at the angle of the frame as a level. Then he picks up fish in the net by a dip net. The catchability of fish by the net depends on the movement of fish in water. It is operated mostly during the water ascending season and receding season when fish migrate in and out the beel.

Species selectivity

The lift net is more or less non-selective gear, but it catches mostly those migratory species or highly mobile fish in the canal. A total of 27 species were identified in the 14 collections from June/ July to October (Table 6). The dominant species in the catches were small miscellaneous fish such as puti P.stigma, kakila X. cancila, kholisha C. fasciata chanda A. nama, baila G. guris and gutum L. guntia. The species, which are resident in the beel proper and less mobile such as koi A. testudineus, shing, H. fossilis taki C. punctatus, shol C. striata and magur C. batrachus, were rarely caught by the lift net.

Carps including catla C. catla, rui L. rohita, mrigal C. mrigala, silver carp H. molitrix common carp Cyprinus carpio var. Communis, mirror carp Cyprinus carpio var. specularis, grass carp Ctenopharyngodon idella and kalibaous Labeo calbasu were found in the catches in September and October, but not in June/ July. Except a few from natural sources, most of carps were from stocked fingerlings. Grass carps C. idella were from stocked fingerlings as a mix species. The carps in terms of number contributed 7.29% of the catches in September and 28.37% in October. Of them C. catla, rui L. rohita, mrigal C. mrigalal were dominant.

Length selectivity

Due to limited number of collection, few species had enough samples for estimating [L.sub.50%] and selective range (Table 8). Puti P. stigma had the [L.sub.50%] value of 5.74 cm in June/ July, and increased to 7.52 cm in September and to 8.11 cm in October. The increments of the monthly [L.sub.50%] was faster for the lift net than that for the gill net (Tables 3 and 8), suggesting less size selectivity is lift net for this species. Chanda A. nama had the [L.sub.50%] of 5.58 cm in June/ July and 6.47 cm in September. For the remaining species, the [L.sub.50%] value was 5.95 cm for kholisha C. fasciata, 14.76 cm for kakila X. cancila, 25 cm for catla C. catla, 27.97 cm for rui L. rohita and 21.68 cm for mrigal C. mrigala.

Push Net (Local Name: Thela jal):

Material and structure

The push net is triangular in shape and consists of two parts, bamboo frame and net. The triangular frame is constructed with three pieces of bamboo poles. One of them is longer to use as a handle. The net which is conic shape is tied on the frame. The mesh size is 1.0 cm.

Fishing operation

Push net is used by subsistent fishermen. One man can operate walking in shallow water and pushing the net along the shore, particularly in the area infested by water hyacinth or rooted vegetation.

Species selectivity

Push net only catches small prawns and miscellaneous fish (Table 6). In this study only one collection was obtained in August. The catches were puti P. stigma (2 fish), kholisha C. fasciata (93) taki C. punctatus (3), baim M. armatus (1) and boicha C. channa (49).

Length selectivity

Kholisha C. fasciata had sufficient sample size for the length selectivity analysis. It had the [L.sub.50%] value of 6.81 cm and selectivity range of 6.18 cm-7.24 cm (Table 8).

Tubular Trap (Local name: Dughair):

Materials and structure

Dughair is a tubular shaped bamboo trap. Its length is about 60 cm. The mouth is located at one end of the trap and has a diameter of 40.0 cm bearing a tongue, a small bamboo fence of about 20.0 cm long extending out from mouth. The tongue divides the mouth vertically into two equal size entrances. There are two uni-directive valves in the trap, one at the mouth and rest one in the middle portion to prevent the escape of fish and prawn. The tail of the trap is 53.0 cm high and has a small door to get the catch. The space between bamboo sticks (mesh) of the trap is about 0.8 cm.

Fishing operation

The trap is usually set on the bottom of canal perpendicularly to the shore with its mouth facing towards canal and tail placing the shore line. A short bamboo fence (about 61.0- 91.0 cm long) is connected with tongue to increase the entrance of fish and prawn into the trap. There are about 20- 40 traps for each fishing unit. They are set in the evening and harvested in the morning or vise-versa.

Species selectivity

Seventeen collections of Tubuler trap were obtained. They consisted of 12 species of fish and prawns (Table 6). Of them, prawns were the most dominant followed by baila G. guris. Prawn contributed 93.25% of the total catches in June/ July, and 46.42% in September. The catches of this species increased greatly from June to September. Prawns and baila occurred mainly in khals near the outlets of the beel, where the dughair fishery was intensive. The remaining species such as taki C. punctatus, shing H. fossilis, tengra M. vittatus, aire Mystus aor, koi, gaura, raikhor, kholisha, mola and boicha were minor species.

Length selectivity

The [L.sub.50%] and selectivity range ([L.sub.25%] - [L.sub.75%]) of baila 18.20 cm and 14.86- 21.33 cm in August and 20.32 cm and 17.66- 22.94 cm in September (Table 7).

Conclusions

People use all possible types of fishing gear, ranging from bare hand to sophisticated seine and gill nets to catch fish and prawn from floodplains for decades. But they are not concerned about the productivity of this area. They fish indiscriminately which declines the fish production alarmingly. So, the guideline of using fishing gear is a crying need to pass legislation banning the use of harmful gear. This will help to grow of stocked carp and increase fish production through safe recruitment. Besides, extension program is necessary for the fishermen which will enhance the fish production. Seine and lift nets are identified as highly detrimental to the floodplain fish and hence those are to be restricted from June to October.

References

Alam, S.S., M.Y. Ali and C. Tsai, 1997. Open water fisheries of Bangladesh. In Bangladesh Centre for Advanced Studies, Eds., Tsai, C. and M. Y. Ali, Dhaka: Bangladesh Center for Advanced Studies and University Press Limited, pp: 137-152.

Choudhury, M., 1989. Resource Exploitation in Beels: Training in management of Beel (Ox-Bow Lake) Fisheries. Central Inland Capture Fisheries Research Institute, Barackpore, India. Associate Press Limited. DOF, 1995. Project Performa, Third Fisheries Project (Revised). Department of Fisheries, Government of the Peoples Republic of Bangladesh.

El Musa, M., 1982. Mesh Selectivity experiments in Kuwait. Report on the workshop on assessment of the shrimp stocks of the west coast of the Gulf between Iran and Arabian Peninsula, Kuwait, 17-22 October, 1981. FAO, Regional Fishery Survey and Development Project, Doha, Qatar. DP/RAB/0015.

FRI., 1992. Fish food study of the floodplains under the third fisheries project. Progress report, Fisheries Research Institute, Santahar, Bogra, Bangladdesh..

Jones, R., 1976. Mesh regulation in the demersal fisheries of the South China Sea area. Manila, South China Sea Fisheries Development and Coordinating programme. SCS/76/WP/34, pp: 75.

Pope, J., A. Margetts and J.M. Hamely, 1975. Manual of methods for fish stock assessment. Part 111. Selectivity of fishing gear. FAO Fisheries Tecnical Paper, 41( Rev. 1): 65.

Sparre, P. and S.C. Venema, 1992. Introduction to tropical fish stock assessment. Part 1. Manual. FAO Fisheries Technical Paper No. 306.1, Rev. 1. Rome, FAO, pp: 376.

Siddeek, M.S.M., 1986. Mesh selectivity and biological impact studies on a new fish-cum-shrimp trawl in Palk Bay, Srilanka. In The First Asian Fisheries Forum, Asian Fisheries Society, Manila, Philippines. Eds.,

Maclean, J.L., L.B. Dizon and L.V. Hosillos, Srilanka: Associate Press. pp: 417-420.

Yadava, Y.S. and V.V. Sugunan, 1992. Prospect of Fisheries Development. Bulletin No. 64. Central Inland Capture Fisheries Research Institute, ICAR, Barckppore, India, pp: 17.

(1) Shafiqur Rahman, (2) Abdur Razzaaque and (3) A.K.M. Saiful Islam

Bangladesh Fisheries Research Institute, Mymensingh-2201, Bangladesh.

Corresponding Author: Shafiqur Rahman, Bangladesh Fisheries Research Institute, Mymensingh-2201, Bangladesh. H/P: +8801730302661, email: shafiqbfri@yahoo.com
Table 1: List of fishing gear found to use in Chanda beel during
June/ July to October.

Sl.                         Types of gear (Figure 2)
No.

1     Fish Net
                       i) Gill net (puti/ koi jal)

                       ii) Cast net (jhaki jal)

                       iii) Seine net (ber jal)

                       iv) Lift net (veshal jal)

                       v) Push net (thela jal)

                       vi) Clap net (buri/ bhuti jal)

2     Fish Trap
                       i) Tubular trap (ichar dughair)

                       ii) Tubular trap (koi dughair)

                       iii) Box trap (ghuni)

3     Hook and Line
                       i) Regular long line (dhawn borshi)

                       ii) Hook and line with water
                       hyacinth as float (dhap/nol borshi)

                       iii) Hook and line with bamboo
                       stick (borshi)

                       iv) Bamboo made hook (chasra)

4     Spear/ Harpoon
                       i) Tuft of sharp-pointed steel
                       wires (umbrella stick-rickshaw
                       spoke) without barb (full-kuchi)

                       ii) Tuft of rods with/without barb
                       (jhupi)

                       iii) Tuft of split-bamboo pieces
                       with barbed iron point, which
                       attached to the shaft by cords
                       (jhuti)

                       iv) Tuft of split-bamboo pieces,
                       pointed end covered with iron cap
                       (koach)

Table 2: Species composition of catches of different mesh gill
nets, Chanda beel, June/ July to September.

Species        2.54 cm mesh             3.18 cm mesh

               Jun/Jul   Aug    Sep     Jun/Jul  Aug    Sep

Baila          38        14     7       258      57     117
Baim           10        1      3       46       97     35
Bheda          --        14     8       --       68     72
Boal           --        --     --      10       2      --
Boicha         --        14     --      --       22     --
Chanda         5         --     --      10       --     2
Darkina        --        --     --      3        --     --
Gutum          --        --     --      16       --     --
Kakila         8         1      -       7        6      41
Kholisha       348       88     191     422      286    242
Koi            238       8      --      273      105    23
Magur          --        --     --      6        13     --
Pabda          --        --     2       --       4      4
Pholi          --        --     --      8        3      --
Puti           275       251    308     389      284    435
Shol           13        --     --      94       16     2
Shing          407       16     88      460      277    52
Taki           195       1      --      380      66     18
Tatkini        --        1      --      --       --     --
Tengra         240       11     --      268      108    34
Number
Species        12        13     9       17       17     14
Fish           1777      420    607     2650     1414   1077
Collection     11        3      4       16       11     8

Species        3.81 cm mesh

               Jun/Jul   Aug    Sep

Baila          --        68     62
Baim           3         2      5
Bheda          --        24     23
Boal           --        2      --
Boicha         --        --     --
Chanda         --        --     1
Darkina        --        --     --
Gutum          --        8      --
Kakila         --        --     --
Kholisha       2         74     182
Koi            30        24     175
Magur          --        4      1
Pabda          --        1      8
Pholi          --        --     --
Puti           --        87     287
Shol           2         1      18
Shing          65        72     114
Taki           33        23     --
Tatkini        --        --     --
Tengra         14        19     29
Number
Species        8         15     13
Fish           149       409    905
Collection     2         6      8

Table 3: Monthly [L.sub.50%] (cm) and selective range ([L.sub.25%]
[L.sub.75%], cm) of different mesh gill nets for dominant
species, Chanda Beel, June/July to September.

Species    Month       2.54 cm mesh
                       [L.sub.50%]    [L.sub.25%]-   [L.sub.75%]

Puti       June/July   7.90           6.66           9.16
           August      7.83           7.46           8.20
           September   7.66           7.17           8.14
           October     7.92           7.45           8.39

Kholisa    June/July   6.56           5.62           6.86
           August      6.44           6.02           6.86
           September   7.06           6.63           7.49
           October     8.57           8.00           9.13

Shing      June/July   15.51          14.45          16.57
           August      --             --             --
           October     17.89          15.30          20.49

Koi        Jun/Jul     7.64           7.05           8.22
           September   --             --             --

Baila      June/July   --             --             --
           September   --             --             --

Taki       June/July   12.34          11.13          13.55

Tengra     June/July   12.77          10.62          14.90

Species    Month       3.18 cm mesh
                       [L.sub.50%]    [L.sub.25%]-   [L.sub.75%]

Puti       June/July   7.10           6.36           7.84
           August      7.81           7.22           8.41
           September   8.17           7.68           8.66
           October     8.06           7.55           8.57

Kholisa    June/July   6.46           5.87           6.97
           August      6.88           6.33           7.43
           September   7.45           6.99           7.93
           October     8.19           7.72           8.65

Shing      June/July   16.16          15.00          17.32
           August      15.85          14.85          16.86
           October     --             --

Koi        Jun/Jul     7.53           6.77           8.28
           September

Baila      June/July   15.95          14.26          17.63
           September   16.94          14.76          19.12

Taki       June/July   13.40          12.66          14.17

Tengra     June/July   11.45          10.49          12.40

Species    Month       3.81 cm mesh
                       [L.sub.50%]    [L.sub.25%]-   [L.sub.75%]

Puti       June/July
           August      8.07           7.45           8.69
           September   8.22           7.65           8.80
           October     9.61           9.01           10.29

Kholisa    June/July   --             --             --
           August      7.96           7.42           8.51
           September   8.57           8.10           9.02
           October     --             --             --

Shing      June/July   --             --             --
           August      17.06          15.64          18.48
           October     18.28          17.14          19.42

Koi        Jun/Jul     --             --             --
           September   10.10          9.39           10.80

Baila      June/July   --             --             --
           September   --             --             --

Taki       June/July   --             --             --

Tengra     June/July   --             --             --

Table 4: Species composition of catches of different mesh cast
net, Chanda Beel, June/ July to October.

Species                 1.0 cm mesh     1.5 cm mesh
                        Jun/Jul   Sep   Jun/Jul   Oct

Baila                   40        --    --        2
Baim                    11        --    --        --
Banshpata               --        --    --        5
Boal                    3         --    --        --
Bugury                  --        --    --        --
Chanda                  49        --    --        11
Cheng                   5         --    --
Dhela                   --        --    --        --
Gaura tengra            --        27    --        --
Ghunia                  --        --    --        1
Gutum                   7         --    --        --
Kakila                  -         --    --        1
Kholisha                34        -     127       --
Khorsola                --        --    --        --
Mola                    --
Prawn (gura chingri)    261       --    --        --
Puti                    34        --    --        4
Taki                    12        --    --        --
Tengra                  14        --    119       --
Number
Species                 11        1     2         6
Fish                    470       27    246       24
Collection no.          3         1     1         2

Species                 2.0 cm mesh
                        Jun/Jul   Aug   Sep

Baila                   --        --    80
Baim                    --        --    --
Banshpata               --        --    --
Boal                    --        --    --
Bugury                  --        --    --
Chanda                  43        43    --
Cheng                   1         1     --
Dhela                   --        --    --
Gaura tengra            --        --    --
Ghunia                  --        --    --
Gutum                   --        --    --
Kakila                  --        --    --
Kholisha                91        --    --
Khorsola                --
Mola                    --        --    55
Prawn (gura chingri)    185       --    --
Puti                    13        --    --
Taki                    2         --    --
Tengra                  14        14    --
Number
Species                 7         3     2
Fish                    349       58    135
Collection no.          4         1     4

Species                 2.5 cm mesh
                        Jun/Jul   Sep   Oct

Baila                   22        44    21
Baim                    --        --    3
Banshpata               --        --    --
Boal                    --        -1
Bugury                  --        --    8
Chanda                  6         --    24
Cheng                   --        --    --
Dhela                   --        --    23
Gaura tengra            --        --    2
Ghunia                  --        --    1
Gutum                   --        --    --
Kakila                  --        --    --
Kholisha                94        --    2
Khorsola                1         --    --
Mola                    --        --    2
Prawn (gura chingri)    69        --    --
Puti                    1         31    14
Taki                    1         --    --
Tengra                  6         --    11
Number
Species                 88        2     13
Fish                    200       75    112
Collection no.          2         5     2

Table 5: Monthly [L.sub.50%] (cm) and selective range
([L.sub.25%]/[L.sub.75]%cm) of different mesh cast net for
dominant species, Chanda beel, June/July to October.

Species    Month       1.0 cm mesh
                       [L.sub.50%]   [L.sub.25%]-
                                     [L.sub.75%]

Chanda     June/July   5.28          4.60-5.95

Baila      June/July   10.91         9.62-12.2
           September   --            --

Puti       June/July   5.08          4.46-5.7
           September   --            --

Kholisha   June/July   4.80          4.24-5.38

Tengra     June/July   --            --

Species    Month       1.5 cm mesh
                       [L.sub.50%]   [L.sub.25%]-
                                     [L.sub.75%]

Chanda     June/July   5.99          5.49-6.49

Baila      June/July   --            --
           September   --            --

Puti       June/July   --            --
           September   --            --

Kholisha   June/July   5.48          4.96-6.0

Tengra     June/July   13.8          8.98-18.6

Species    Month       2.0 cm mesh
                       [L.sub.50%]   [L.sub.25%]-
                                     [L.sub.75%]

Chanda     June/July   6.17          5.72-6.62

Baila      June/July   --            --
           September   12.84         5.73-19.19

Puti       June/July   --            --
           September   --            --

Kholisha   June/July   6.16          5.68-6.63

Tengra     June/July   --            --

Species    Month       2.5 cm mesh
                       [L.sub.50%]   [L.sub.25%]-
                                     [L.sub.75%]

Chanda     June/July                 --

Baila      June/July   15.76         13.74-25.7
           September   13.94         12.36-15.5

Puti       June/July   --            --
           September   10.28         8.81-11.7

Kholisha   June/July   6.79          5.60-7.98

Tengra     June/July   --            --

Table 6 Species composition of catches of seine net,
lift net and tubular trap (ichar dughair), Chanda beel,
June/July to October.

Species           Seine net                Lift net

                  Sep      Oct   Jun/Jul   Sep    Oct

Aire              --       --    --        --     --
Baila             --       --    18        13     2
Baim              91       --    10        1      5
Banshpata         64       --
Bheda             78       --    --        --     2
Boal              --       --    --        --     3
Boicha            --       --    --        --     --
Catla             3        44    --        20     79
Chanda            92       --    30        198    2
Common carp       2        --    --        1      10
Gaura             --       --    --        --     4
Grass carp        --       --    --        --     12
Gutum             --       147   102       --     --
Kakila            4        145   --        250    352
Kaliboush         --       --    --        --     1
Kholisha          5        242   124       --     152
Koi               --       --    1         --     -1
Magur             --       --    --        --     1
Mirror carp       --       --    --        --     5
Mrigal            2        5     --        34     66
Mola              --       --    17        75     --
Pabda             --       --    --        --     15
Pholi             --       --    5         6      7
Galda chingri     --       --    --        --     --
Puti              37       --    369       253    216
Raikhor/tatkini   --       --    --        3      --
Rui               12       9     --        7      72
Shol              --       --    --        --     1
Shing             --       --    --        --     --
Silver carp       --       33    --        1      18
Taki              --       --    10        --     2
Tengra            --       --    6         1      --
Number
Species           11       6     12        15     22
Fish              390      625   692       863    1027
Collection No.    2        3     2         3      9

Species           Tubular trap (ichar dugair)

                  Jun/Jul  Aug   Sep

Aire              --       9     2
Baila             16       226   329
Baim              --       --    --
Banshpata         --       --    --
Bheda             --       --    --
Boal              --       --    --
Boicha            1        --    --
Catla             --       --    --
Chanda            --       --    --
Common carp       1        --    --
Gaura             --       --    --
Grass carp        --       --    --
Gutum             --       --    --
Kakila            --       --    --
Kaliboush         --       --    --
Kholisha          1        --    --
Koi                        --    --
Magur             --       --    --
Mirror carp       --       --    --
Mrigal            --       --    --
Mola              1        --    --
Pabda             --       --    --
Pholi             --       --    --
Galda chingri     594      260   --
Puti              --       --    --
Raikhor/tatkini   1        --    --
Rui               --       --    --
Shol              --       --    --
Shing             --       17    --
Silver carp       --       -     --
Taki              17       15    --
Tengra            --       33    --
Number
Species           9        6     2
Fish              637      560   331
Collection No.    4        4     4

Table 7: Monthly [L.sub.50%] (cm) and selective range
([L.sub.25%] and [L.sub.75%], cm) of push net, seine net, lift
net and tubular trap (ichar dughair) for dominant species, Chanda
beel, June/July to October.

Species    Month       Push net

                       [L.sub.50%]   [L.sub.25%]-
                                     [L.sub.50%]

Puti       June/July
           September
           October

Kholisha   June/July
           August      6.18          6.18
           October

Chanda     June/July
           September

Kakila     September

Catla      October

Rui        October

Mrigal     October

Baila      August
           September

Baim       September

Species    Month       Seine net

                       [L.sub.50%]   [L.sub.25%]-
                                     [L.sub.50%]

Puti       June/July
           September
           October

Kholisha   June/July
           August      7.24
           October     5.0           4.32-5.67

Chanda     June/July
           September   6.31          5.79-6.83

Kakila     September   17.74         12.29-23.17

Catla      October

Rui        October

Mrigal     October

Baila      August
           September

Baim       September   12.05         10.78-13.32

Species    Month       Lift net

                       [L.sub.50%]   [L.sub.25%]-
                                     [L.sub.50%]

Puti       June/July   5.74          4.24-7.23
           September   7.52          6.97-8.08
           October     8.11          7.60-8.61

Kholisha   June/July   5.95          5.45-6.45
           August
           October

Chanda     June/July   5.58          5.03-6.12
           September   6.47          5.77-7.07

Kakila     September   14.76         11.73-17.78

Catla      October     25.0          23.0-27.17

Rui        October     27.97         24.37-31.55

Mrigal     October     21.68         19.29-24.07

Baila      August
           September

Baim       September

Species    Month       Tubular trap (ichar dughair)

                       [L.sub.50%]   [L.sub.25%]-
                                     [L.sub.50%]

Puti       June/July
           September
           October

Kholisha   June/July
           August
           October

Chanda     June/July
           September

Kakila     September

Catla      October

Rui        October

Mrigal     October

Baila      August      18.20         14.86-21.33
           September   20.32         17.66-22.94

Baim       September

Table 8: List of fish and prawn species caught by different
gear, Chanda beel, June/ July to October.

Sl.
No.   Local Name       Common Name (Scientific Name, Family Name)

1     Aire             Bagrid Cat fish (Mystus aor, Bagridae)
2     Baila            Gobies (Glossogobius giuris, Gobidae)
3     Baim             Mastacembelid eel (Mastacembelus armatus,
                         Mastacembelidae)
4     Banshpata        Minor carp (Danio devario, Cyprinidae)
5     Bheda            Leaf fish (Nandus nandus, Nandidae)
6     Boal             Eurasian catfish (Wallago attu, Siluridae)
7     Boicha/chuna     Climbing perches (Colisa channa,
                         Anabantidae)
8     Buzury           Bagrid Catfish (Mystus tengra, Bagridae)
9     Chanda           Snooks (Ambassis nama, Centropomidae)
10    Catla            Indian major carp (Catla catla, Cyprinidae)
11    Cheng            Snakehead (Channa gachua, Channidae)
12    Common carp      Common carp (Cyprinus carpio var. Communis,
                         Cyprinidae)
13    Darkina          Minor carp (Esomus danricus, Cyprinidae)
14    Dhela            Minor carp (Rohtee cotio, Cyprinidae)
15    Galda chingri    Giant prawn (Macrobrachium rossenbergii,
                         Palaemonidae)
16    Gaura tengra     Bagrid Catfish (Leiocassis rama, Bagridae)
17    Gaura            Schilbeid catfish (Clupisoma gaura,
                         Schilbeidae)
18    Ghunia           Carp (Labeo gonius, Cyprinidae)
19    Grass carp       Chinese major Carp (Ctenopharyngodon
                         idella, Cyprinidae)
20    Gutum            Loaches (Lepidocepalus guntia, Cobitidae)
21    Kakila           Needle fish (Xenentodon cancila, Belonidae)
22    Kaliboush        Indian major carp (Labeo calbasu,
                         Cyprinidae)
23    Kholisha         Climbing perches (Colisa fasciata,
                         Anabantidae)
24    Khorsola         Mullet (Rhinomugil corsula, Muglidae)
25    Koi              Climbing perches(Anabas testudineus,
                         Anabantidae)
26    Magur            Air breathing catfish (Clarias batrachus,
                         Claridae)
27    Mirror carp      Common carp (Cyprinus carpio var.
                         specularis, Cyprinidae)
28    Mrigal           Indian major carp (Cirrhina mrigala,
                         Cyprinidae)
29    Mola             Minor carp (Amblypharyngodon mola,
                         Cyprinidae)
30    Pabda            Eurasian catfish (Ompok pabda,Siluridae)
31    Pholi            Featherback (Notopterus notopterus,
                         Notopteridae)
32    Prawn (gura      Freshwater small shrimp (Macrobrachium
        chingri)         lomarrei, M. Dayanus, M. Dolichodactylus
                         etc. & Leander styliferus, Palaemonidae)
33    Puti             Minor carp (Puntius stigma, Cyprinidae)
34    Rui              Indian major carp (Labeo rohita,
                         Cyprinidae)
35    Shol             Snakehead (Channa striata, Channidae)
36    Shing            Stinging catfish (Heteropneustes fossilis,
                         Heteropneustidae)
37    Silver carp      Chinese major carp (Hypophthalmichthys
                         molitrix, Cyprinidae)
38    Taki             Snakehead (Channa punctatus, Channidae)
39    Tatkini/Rikhor   Carp (Cirrhina reba, Cyprinidae)
40    Tengra           Bagrid cat fish (Mystus vittatus, Bagridae)
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Article Details
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Title Annotation:Original Articles
Author:Rahman, Shafiqur; Razzaaque, Abdur; Islam, A.K.M. Saiful
Publication:American-Eurasian Journal of Sustainable Agriculture
Article Type:Report
Geographic Code:9BANG
Date:Dec 1, 2009
Words:6828
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