The By-catch From the Artisanal Shrimp Trawl Fishery, Gulf of Paria, Trinidad

VISHWANIE MAHARAJ and CONRAD RECKSIEK

Introduction in this region (Jones and Villegas, 1980). In Trinidad, the artisanal trawlers fish For the western central Atlantic region, within the nearshore region (mainly in­ The continental shelf of northeastern Klima (1976), concluded thatthe shrimp side the 5-fm isobath) ofthe GulfofParia. South America is a highly productive fisheries discarded approximately Four penaeid shrimp species are the main fishing zone extending from east Vene­ 1,000,000,000 kg of finfish. For most target of this artisanal trawl fishery: zuela to eastofthe Amazon River (Naidu penaeid shrimp fisheries, this by-catch is Penaeus schmitti, P. subtilis, P. notialis, and Boerema, 1972). The annual shrimp the main component of trawl catches at and Xiphopenaeus kroyeri. landings range from 15,000,000 to 75-95 percentofthe total weight (Alsopp, Commercial landing statistics for Tri­ 20,000,000 kg (Villegas and Dragovich, 1982; Griffiths and Simpson, 1972). nidad and Tobago are collected by the 1984). However, an estimated yearly Finfish weight to shrimp weight ratios Fisheries Division, Ministry of Food average of 200,000,000 kg of demersal have been used to estimate quantities of Production, and accordinglyin 1986the finfish by-catch is thought to be discarded by-catch. However, most reported ratios artisanal trawl fishery was responsible are calculated for the nonartisanal fish­ for 30 percent (108,000 kg) of the total ery. Finfish:shrimp ratios vary widely shrimp catch (Fisheries Division, Trini­ from area to areaeven in the same region. dad and Tobago, 1986). This study was Slavin (1982) reported estimates of 19 for formulated to determineby-catch:shrimp ABSTRACT-Samples of shrimp trawl the north central Gulf of Mexico and 40 weight ratios to estimate the magnitude catches were collected from a commercial for the northeast Gulf of Mexico. In the of the incidental catch, and to describe artisanal vesselfishing inside the 6-fin isobath in the GulfofParia, Trinidad. From August South Carolina offshore shrimp fishery, species composition and seasonality of 1986 to May 1987, 34 late evening-early Keiser (1976) found the finfish:shrimp trawl catches for the artisanal trawl fish­ morning trawl trips were made and 97hauls ratio to be highly variable (3-136), with ery in the Gulf of Paria. were sampled. a definite seasonaltrend. Furnell, (1982) Annual ratio estimates were 9 (SD 1.3) finfish:shrimp and 14. 7 (SD 2.0) by-catch: estimated a ratio of 13 inside the lO-fm Materials and Methods shrimp, with the highestratios observedAug­ isobath offGuyana and observed thatthis ust through Decemberandthe lowestfrom late ratio decreased with increasing depth. Study Area January through May, the dry season. Ex­ Other work in this region indicates values This study was based on the local ar­ trapolation of ratios, using shrimp catch of4 for the offshore fishery in Guyana (de tisanal shrimp trawl fishery operating statistics, indicates thatfor1986, 974,oookg offinfish and620, 000kg ofcrabs, Callinectes Mesquite, 1982), 15 for the northern from Orange Valley in the GulfofParia, spp., were caught incidentally by artisanal coast of Venezuela, and 10 for Brazil Trinidad (Fig. 1), or, more specifically, shrimp trawlers fishing in the GulfofParia. (Griffiths and Simpson, 1972). Watts and the Carom platform in the depth range 0-6 Ofthis totalincidental catch (1 ,594,000kg), Pellegrin (1982) estimated finfish: fm. This Gulf is shallow with a mean about 1,500,000 kg were discarded (94 percent). shrimp ratios in Texas, and reported depth of 15 fm, flat bottomed, and gently Fourpenaeidshrimpspeciesare targeted: variation between years (12.94 in 1980 sloping, particularly along the coast Penaeus schmitti, P. notialis, P. subtilis, and and2.55 in 1981), attributed to the Texas (Gines, 1972). Composition of the bot­ Xiphopenaeus kroyeri. Callinectes spp. were closure in 1981. Dragovich and Villegas tom is mainly mud and silty-mud brought caught in large quantitiesfrom Augustto mid­ (1983) reported ratios ranging from 2 to in by the Orinoco River and its tributaries January. Small (4-15 cm)pelagicanddemer­ sal species oflittle commercial importance 130 (average 19.5) for the artisanal traw1 (VanAndel and Sachs, 1964). dominated the finfish by-catch: Harengula fishery operating along the northern coast The Gulf of Paria has been described spp., Cetengraulis edentulus, Chloroscom­ of Brazil. as a relatively calm, slightly stratified, brus chrysurus, Eucinostomous spp., semi-enclosed estuarine zone, whereout­ Diapterus rhombeus, and Cyclopsetta spp. flows from the Orinoco and other rivers Altogether, the monthly percentage of the The authors are with the Department of Fisheries, species ranged from 70 to 85 percent ofthe Animal and Veterinary Science, University of mix with the water from the open ocean total finfish by-catch. Rhode Island, Kingston, RI 02881. (Gines, 1972). Seasonal variability in the

53(2), 1991 9 surface salinity is tied to the Guyana cur­ Figure I.-Location of 97 60'28' rent and Orinoco River (VanAndel and trawl catches (hatched W areas) by anartisanal trawl­ Sachs, 1964). During the wet season er, August 1986 through (June-December), surface salinities can May 1987, Gulf of Paria, be low (10-20%0), while in the dry sea­ Trinidad and Tobago. Pt. son (January-late May) salinities may be as high as 35%0 (Kenny and Bacon, 1981). Thecoastal zone in the GulfofParia is IO'33'------\---~~~r-r\t----1 considered to be heavily polluted due to N the highly populated areas nearby and in­ dustrial development'. Gulf of The Commercial Fishery Poria and Catch Statistics PI The local artisanal trawl fleets fish within the 6-fm isobath in the Gulf of Paria close to their home ports, where 10'27' ----+-+--~r~-J_-1------1 they usually land most of their catch N Valley (Maharaj, 1989). Commercial statistics are collected on a daily basis by the Fisheries Division, Ministry of Food Production. Shrimp landings were ex­ tracted from these records for 1986 from the key sites Orange Valley, San-Fernan­ Gull of do and Otaheite in the Gulf of Paria Pone PI (Maharaj, 1989). Also, members ofthe fishing community were interviewed in­ formally during the course ofthis study.

Vessel, Gear, and Operation The commercial vessel used in this board from the stern; then the rest ofthe other conditions. Also, the number of study was an artisanal trawl vessel oper­ net was let out as the vessel moved for­ hauls per trip (per day's fishing) was de­ ating out of Orange Valley. This vessel ward. Finally, the otter doors were pendent on these and other factors. was 9.8 m in length, wooden, and pow­ thrown overboard, and the time at this ered by an inboard diesel engine. There pointwas recorded as the startofthe tow. Sampling Method were no other mechanical aids on the The ratio of warp to depth was usually It was decided that samples would be vessel, nor were there any electronic between 2: 1 and 3: 1 (according to the taken from a "typical" artisanal vessel devices. The crew consisted of two in­ vessel's captain). Each warp was made operating under" normal" commercial dividuals: The captain and a deck hand. fast to the fishing vessel. conditions. Trawl catches were sampled A single four-seamed trawlnet was After the completion ofeach haul, the at seafrom this vessel which operated out used with head rope length of 10 m, and net was broughtaboard the vessel, thecod ofOrange Valley. The seniorauthor was codend mesh size of3. 8 cm. The ground end untied, and the catch sequentially on board to collect weekly samples from rope, 14mlong, was weighted using lead emptied into a number ofbins (each bin 8 August 1986 to 26 January 1987 and pieces of 7-13 cm. Paired wooden rec­ held about 25 1). During the following bimonthly from 6 February 1987 to 22 tangulardoors (1.2 m X 0.5 m) were at­ haul, this catch was sorted by the crew. May 1987. tached to this net. Shrimp and some finfishes were kept and Prior to the study, it was decided to The entire operation of setting and the rest ofthe catch was discarded at sea. stratify the sampling period (August 1986 hauling in the trawl gear was done manu­ The start and end of each haul were to May 1987) into weekly intervals (each ally. Initially the cod end was set over- recordedas the time when the trawldoors week began on Monday and ended on were thrown overboard, and retrieved Sunday). Weekly stratification was I Point Lisas environmental project VII. Fisheries. aboard the vessel, respectively. Tow chosen to capture the short-term fluctua­ Institute ofMarine Affairs report submitted to Point Lisas Industrial Port Development Corporation, duration varied from 1to 3 hours depend­ tions reported in trawl catches (Bazigos, May 1982,25 p. ing on the area, depth, time ofyear, and 1974). Onesampleday perweekwas then

10 Marine Fisheries Review chosen randomly using a Lotus 1232 n n of Paria. The crab by-catch was com­ function (@rand), which generated ran­ R; = (L F;)-F;-+- (L S;)-S;, puted as the difference between the total dom numbers between 1 and 7. ;=1 ;=1 by-catch and finfish by-catch, and its an­ Aboard the vessel the following data nual variance was calculated as indicated were recorded for each haul: Tow dura­ above. Since no data were collected for tion, fishing area, depth, number ofbins June and July 1987, mean ratios for May filled, and approximate weight (to the n 1987 and August 1986 were used as ratio nearest kilogram) of finfishes, shrimp, Rm = L (R;) -+- n, estimates for June andJuly, respectively. and crabs retained by the captain for ;=1 Mean annual ratios were estimated market. from datacollectedduring the 10-month On each sample day, all trawl hauls n sampling period, using the equations were sampled by choosing oneofthe bins L (R; - Ro )2 listed above, with the exception that n = into which the catch was placed. The bin Var(R ) = _;=_1 _ 97 and Rm is the mean annual ratio. Each was chosen haphazardly and considered m n(n-l) ofthe annual by-catch quantities was then representative of that particular haul. calculated as the product of these ratios Samples were kept on ice for later pro­ where: and the annual shrimp landings for 1986. cessing (Maharaj, 1989). Catch samples Discards from the were sorted and classified to the lowest Ro = monthly ratio, taxon possible. Total weight and number F; = finfish weight in the ith haul, Artisanal Fishery of each taxon were recorded. S; = shrimp weight in the ith haul, In this artisanal trawl fishery, notall of n = number of hauls sampled per the by-catch is discarded at sea. Some of Data Analysis month, this by-catch is marketed at landing sites, R; = Jacknife pseudo value, and and these quantities are recorded by the Estimation ofCatch Rates Rm = Jacknife ratio estimate. Fisheries Division. From these records From the Sample Data were obtained annual estimates of by­ Total weightperhaul and total numbers By-catch Estimates for catch sold by this artisanal fishery. Dis­ per haul were calculated by multiplying The Artisanal Fishery cards were then calculated as the dif­ the number of filled bins per haul by ference between the estimates of total the weight and numbers in the sample, Jacknife monthly ratio estimates were by-catch and these commercial data. respectively. Catch rates expressed as used together with the commercial land­ weight per unit time (kg/hour) and num­ ing statistics, i.e. the shrimp landings (for Results bersperunittime (no.Ihour), weredeter­ 1986), to estimate the total incidental by­ During this lO-month study, 97 hauls mined from the catch data and the haul catch for the artisanal fishery (B): were sampled from 33 trawl trips (each duration. The following order statistics trawl trip = I day's fishing). The entire were used to summarize these results: B = Rm X S, artisanal fleet made over5,OOOtripsdur­ Median (M), lower fourth (Lf ), and up­ ing 1986 (Table 1). The sample hauls Var(B) = Var(R ) X S2 per fourth (Vf ). m represented 220 hours oftrawling time. From the fishing patternofthe vessel used Ratio Estimators in this study, it was concluded that arti­ Two sets of ratios were calculated for sanal vessels trawl in depths between 1.5 each haul sampled: Finfish weight to n and 2.5 fm from August until mid-Jan­ shrimp weight (finfish:shrimp), and total L (Be -Be )2 uary, and after this period they move fur­ by-catch weight (weight of finfish and i-I ther offshore into depths exceeding 3 fm Var(Be ) = '------'---­ crabs) to shrimp weight (by-catch: (n-l) (Maharaj, 1989). shrimp). In an effort to reduce the bias of ratio where: Catch Components estimators, the Jacknife method, modi­ and Abundance fied according to Tukey (Rey , 1983), was B = by-catch estimate, The total (shrimp, finfish, and crab) used to calculate monthly ratios and S = shrimp landings 1986, catch per unit effort (CPUE; expressed variances: Bt = total by-catch, as kg/hour) was highest (usually>100 Be = crab by-catch, kg/hour) during August. Thereafter, this n n Bf = finfish by-catch, and CPUE steadily declined throughout the Be = annual average crab by-catch. remainderofthe wetseason (Fig. 2). This ;=1 ;=1 trend ofdeclining catch rates continued Monthly by-catch estimates (total by­ through the dry season where CPUE did 2Mention oftrade names orcommercial firms does not imply endorsement by the National Marine catch and finfish by-catch) were calcu­ not exceed 50 kg/hour, with median Fisheries Service, NOAA. lated for all three landing sites in the Gulf values between 10 and 20 kg/hour (Fig.

53(2),1991 11 Table 1.-Dispositionofsampling effort with total artisanal fleet effort(number of trips) for 1986. Jacknife monthly ratios based on 97trawl catches byan artlsanaltrawler, August 1986throughMay1987,GulfofParia, Trinidad and Tobago. Commercial shrimplandingsfortheartisanal fishery, 1986,providedby theFisheriesDivl$ion, Ministryof Food Produc­ tion, Trinidad and Tobago. Estimates of crab, finfish, and total by-catch, together with their stand.,d deviations, calculated from the ratios and commercial data.

Item Jan. Feb. Mar. Apr. May June' July' Aug. Sept. Oct. Nov. Dec. Annual

Number of trips Total Fleet effort 638 510 550 598 586 423 404 442 347 350 367 264 5,479

Sampling effort 3 2 2 2 3 4 4 33

Estimated ratios Mean Finfish:shrimp 7.06 2.22 2.41 3.26 5.21 5.21 27.86 27.86 6.17 7.90 58.34 23.04 8.99 S. D. 1.86 0.40 1.15 038 1.12 1.12 22.25 22.25 1.45 2.56 22.29 16.84 1.25

By-catch:shrimp 8.75 3.33 2.72 4.46 7.22 7.22 53.47 53.47 13.74 16.14 87.32 35.03 14.71 S D. 2.30 0.60 1.15 0.72 2.21 221 25.91 25.91 3.32 5.88 31.09 25.66 2.03

Weight (kg) Total Shrimp landings, 1986 11,844 10,951 14,797 15,775 11,679 7,973 6,588 9,181 5,733 5,073 4,577 4,186 108,357

Crab by-catch 20,058 12,133 4,549 18,930 23.475 16,027 168,718 235,117 43,402 41,778 132,623 50,186 619,804

Finfish by-catch 83,575 24,334 35,700 51,426 60,848 41,541 183.540 255,774 35,375 40,099 267,027 96,438 974,132 S. D. 22,030 4,380 17,017 5,994 13,081 8,930 146,582 204,270 8,313 12.987 102,018 70,487 135,447

Total by·catch 103,634 36.467 40,249 70,355 84,323 57,568 352,258 490,891 78,777 81,877 399,650 146,624 1,593,935 S. D. 27,241 6,571 17,017 11,358 25,811 17,621 170,694 237,871 19,035 29,829 142,294 107,405 219,965

,Ratios used for June and July were ratios calculated from May and August data, respectively.

NUMBERS/H KG/H 2,CCO 80

Vl Figure 2.-Median month­ October to 16 kg/hour in November). co « ly catch rates bounded by Thereafter the catch rates fell offfurther, ,800 4: lower and upper fourths, u"" [ f I [I[ remaining at low levels « 10 kg/hour) in ~ [ [ [ basedonthe 97 trawl catches [ [ by an artisanal trawler, Aug­ the dry season. 8 I E 1 "'II: I : ust 1986 through May 1987, Catch rates of finfishes fluctuated GulfofParia, Trinidad and 808 8 throughout the year, with a less pro­ Tobago. nounced seasonal trend than described ~ above. The lowest catch rates were I"" "0 ~ observed during the dry season (median Vl 1[ I [ f I II t t [ t [ l t of <10 kg/hour). E t F E 0 8 In contrast tothe crab and finfish com­ ponents, the highest shrimp catch rates <0001 IC8 were observed from mid-September to I '::! 1 mid-October in the wet season and from 50 t January to May (Fig. 2). Catch rates were ~ '000 [[ [ I~ d d l[ consistently higher during the period 1 ,l " _ [ d 0 0 from March to May (median of3-4 kg/ hour) and lowest during November and 6.80C 140 December. t « >­ Ratio and 3.000 70 0 [If ( [ . l ql[ By-catch Estimates [ , L Annual Jacknife ratio estimates were C ---< 0 A SON 9 J C M A M ASONDJ F M A M 9.00 (SO 1.25) finfish: shrimp and 14.70 MON THS (SO 2.00) by-catch:shrimp (Table 1). The distribution of monthly ratio esti­ mates could also be linked to seasonality, 2). The annual median total catch rate depicted by the crab catch rate data (Fig. with the highest ratios observed during observed, from these 97 hauls sampled, 2). Catch rates were highest in the wet the wet season. The lowest ratios, <10, was 34 kg/hour (Maharaj, 1989). season and decreased markedly from were frequent from late January to May, Distinct seasonality in abundance was November (median of 31 kg/hour in in the dry season (Fig. 3).

12 Marine Fisheries Review BY-CATCH: SHRIMP FINFISH: SHRIMP 125 100

0 75 0 60 ~ ~

Table 2.-Eslimated discards in tne artisanal trawl Figure 4.-By-catchestimates fishery, 1986. for the artisanal trawl fishery BY-CATCH ESTIMATES Item Aml./% Reference based upon 97 trawl catches by 500 an artisanal trawler, August By-catch 93.548 kg Trawl by-catch sold in 1986, landed taken from the commercial 1986 through May 1987, Gulf 400 shrimp landings for the arti­ of Paria, and commercial sanal trawl fishery. 1986'. shrimp landings for the artisanal trawl fishery, 1986, provided 300 Estimated 1.593.935 kg Estimated total discards by-catch taken from Table 1 by the Fisheries Division, Min­ istry ofFood Production, Trini­ 200 By-catch 5.87% Percentage of total esti­ dad and Tobago. The by-catch landed mated by·catch sold. estimates for June and July (*) By-catch 94.13% Percentage of total esti­ were calculated using ratios de­ (,9 100 ~ discarded mated by-catch discaraed. termined for May and August, -.... respectively. V> 'Fish. Div., Minis!. Food Prod., 1986. o o z « V> 20 ::J SHRIMP LANDINGS (1986) o The total annual by-catch estimate for I 16 the Gulf of Paria artisanal trawl fishery I­ in Trinidad was 1,594,000 kg (SD 220,000), composed of974,000 kg (SD 12 135,000) finfish and 620,000 kg (SD 70,800) crabs (Table 1), for reported 8 shrimp landings in 1986 of 108,000 kg (Table 1). The highest quantities of by­ 4 catch were harvested from July to De­ cember, corresponding to the period of a the lowest shrimp landings (Fig. 4). J FMAM J J A SON D About 6 percent (93,600 kg) ofthe total MONTH annual by-catch was probably sold, therefore more than 90 percent of this estimated by-catch was discarded at sea found in these trawl catches. From this January to May. Xiphopenaeus kroyeri (Table 2). study it appears that Penaeus schmitti was only appeared sporadically in the catches mainly present from September to Octo­ from August to January. Callinectes spp. Species Composition ber. In contrast, P. notialis and P. sub­ were caught in large quantities only dur­ Four penaeid shrimp species were tilis dominated the trawl samples from ing the wet season (Maharaj, 1989).

53(2),1991 13 Subadults and juveniles ofthe follow­ with recruitment from estuaries. Gunter 80 percent of that covered by the com­ ing species dominated the finfish by­ (1938) associated this trend in Louisiana mercial fleet; our sampling vessel did not catch: Harengula spp., Cetengraulis with seasonal breeding cycles, influx of venture into the most southerly sections edentulus, Chloroscombrus chrysurus, recruits large enough to be caught in the of the fleet's operational area. Eucinostomous spp., Diapterus rhom­ trawl, or migration of old or young in­ Only 6 percent ofthe by-catch is mar­ beus, and Cyclopsetta spp. These species dividuals from another locality. keted, unlike most artisanal trawl fish­ altogether accounted for 70-85 percent of Another factor which could be partly eries where most by-catch is retained the finfish by-catch. Itwas clearly appar­ responsible for these abundance fluctua­ (Saila, 1983). An estimated 1,500,400kg ent that Harengula spp. and Cetengraulis tions is the change in depth of fishing. offinfish and crabs are discarded annual­ edentulus were present in significant From January to May, fishing depth in­ ly from this artisanal trawl fishery. These quantities only in the wet season. Forthe creased slightly (from I-Urn to >3 fm). discards may provide a large food source other finfish species mentioned above, Furnell (1982) reported that "Assess­ for the crab populations and account for catch rates fluctuated chaotically without ment of incidental catches of fish by the latter's abundance. It was observed any distinct seasonal trend (Maharaj, trawlers operating in Guianese waters during this study that discarded finfish 1989). showed that the largestquantities offish were fed upon by sea birds. Possibly are caught in shallow waters (less than 15 crabs (most of the crabs in the by-catch Discussion fm), whereas the largest quantities of were returned to the sea alive) and other The annual weight ratio estimates of shrimp are caught in deeper waters organisms may also be attracted to these 14.7 (SD2.00) by-catch:shrimpand 9.0 (22-39 fm)." discards (Saila, 1983). However, it is (SD 1.25) finfish: shrimp were compar­ The wide fluctuation in finfish catch generally believed that most of the able to other results from the western cen­ rates observed here are likely typical of discards usually decompose and become tral Atlantic fishing region, which ranged finfish assemblages captured by shrimp remineralized into nitrogen and other from 10 to 20 inside the lO-fm isobath fleets. This is probably attributable to the nutrients (Cushing, 1981; Sheridan et al., (Dragovich and Villegas, 1983; de Mes­ nonrandom distribution offinfish popula­ 1984). quite, 1982; Griffiths and Simpson, tions (Keiser, 1976; Taylor, 1953). In One of the important issues for Trini­ 1972). The annual estimates in this study this fishery we observed a tendency for dad and Tobago is whether groundfish did not reflect the wide variation in the fishermen to avoid areas where large landings by the directed fisheries (demer­ data; the coefficient of variation (SD/ quantities ofby-catch were caught. The sallonglines and trawl) are adversely af­ ratio) was less than 15 percent for the an­ latter could explain the high variances fected by shrimp trawling. Ifthis were the nual estimates. However, during August, of the large ratio estimates in August case, then a host ofmanagement regimes, November, and December when the and November-December, when shrimp based on closed season/areas (Villegas ratios were high (>30), the coefficient of catches were poor. and Dragovich, 1981;Caddy, 1982; Gar­ variation ranged from 50 to 90 percent. TheJacknife method used to calculate cia, 1986) and/or gear restrictions/modi­ Throughout the dry season, an increase the ratio estimates was an appropriate fications (Siedel and Watson, 1978; in shrimp catches and a simultaneous procedure since it not only reduces the Jones, 1976; Hickey and Rycroft, 1983; decrease in the crab and finfish compo­ bias in these ratio estimates, but it also McVea and Watson, 1977), could be nents were apparently responsible for the assumes no particular data distribution employed in an attempt to reduce the low ratios estimated from January to (Rey, 1983). All data recorded were used by-catch. May. In the wet season, the ratios were to estimate the monthly and annual aver­ higher, except for September and Octo­ age ratios. Most authors exclude high Acknowledgments ber, which corresponded to the peak in ratios (>100) from their calculations abundance of P. schmitti, and hence the (Keiser, 1976); however, we decided that We acknowledge the Fisheries Divi­ ratio estimates for these months were to do so would lead to an underestimation sion, Ministry ofFood Production, Ma­ lower than those for August, November, ofby-catch. rine Exploitation, Forestry and the En­ vironment, Trinidad and Tobago, whose and December. Our estimates were based on the as­ These results indicate that the highest sumption that, "on average, " the vessel resources made this study possible. We finfish catch rates occurred during Aug­ in this study was representative of the also want to thank C. Maharaj as well as members of the fishing community for ust-December in the GulfofParia. Many fleet at comparable times and area fished. their assistance during this project. This explanations have been given for sea­ Comparisonofsampling effort and com­ is contribution number 2541 ofthe Rhode sonal finfish catch variations. Lowe­ mercial fishing effort during 1986 is con­ Island Experiment Station. McConnell (1962) found catches of tained in Table 1. As mentioned, the ar­ trawled finfishes in Guiana to be highest tisanal trawl fleet fishes within the 6-fm during the rainy season when they move isobath in the GulfofParia. The distribu­ Literature Cited into shallower areas. Mooreetal. (1970) tion of sampling effort by area for this Alsopp, w. H. L. 1982. Use offish by-catch from shrimp trawling: Future Development. In Fish linked high seasonal finfish abundance in study vessel is depicted in Figure 1. It is by-catch ...bonus from the sea. Report ofa tech­ an inshore area 0-10 fm in Louisiana) our beliefthat this area represents about nical consultation on shrimp by-catch utilization

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