COMPARISON OF CATCH AND BYCATCH WITH BEAM AND OTTER TRAWLS IN THE NORTHEAST SHRIMP FISHERY A report to Northeast Consortium by Captain Bill Lee FN Ocean Reporter 25 Pleasant St Rockport MA 1966 Phone/FAX: 9785462748 oceanreporter@adelphia.net assisted by Melissa Hall, B.S Allan Michael, Ph.D. May 25
Abstract A 17 ft beam trawl was built and tested for the possible application ofthis gear in the northeast shrimp fishery. The 1.75-inch mesh net was fitted with a Nordmore grate and towed from the fishing vessel Ocean Reporter out of Rockport, Massachusetts during the months of January through March, 24. Seven additional vessels reported their catch and bycatch while towing for shrimp using standard otter trawls during the same time period and in the same general area as the vessel using the beam trawl. The beam trawl had a significantly lower catch rate for shrimp than the vessels using standard otter trawls (mean, 82lbslhr vs. 27 lbslhr). This was in part due to the relative size ofthe gear since the opening of the beam trawl was 17 ft and that for the otter trawls ranged from 28-34 ft. Percent bycatch (by weight) for the beam trawl was 13.6% whereas that for the otter trawl fleet was 1.7%. There was a wide variation in bycatch rate among the 7 vessels using the otter trawl (.4-16.5%). Composition ofthe bycatch differed with a higher percentage ofgroundfish in the beam trawl and a higher percentage ofpelagic fish in the otter trawl(s). Fuel consumption was greatly reduced with the use of the beam trawl. The gear is inexpensive to make and can be used with a single warp and from small vessels with lower horsepower. Further modifications might make this gear useful under specific conditions, near hard bottom, or where fixed gear is deployed. Additional research that could be done would be an evaluation the relative impact of the lightweight beam trawl versus the standard otter trawl on the benthic environment. 1
LIST OF FIGURES 1. Dimensions ofthe Net. r... 5 2. Low Impact Shrimp Beam Trawl.., ;... 6 3. Setting Out Beam Trawl... 7 4. Beam Trawl and Nordmore Grate... 7 5. Catch and Bycatch Comparison of Beam and Otter Trawls ;... 9 6. Catch, Bycatch and Bycatch Composition of Otter Trawl Fleet... 1 7. Daily Catch and Bycatch Composition ofocean Reporter... 12 8. Daily Catch and Bycatch Composition oflady Elaine... 13 9. Daily Catch and Bycatch Composition ofmarina Rose... 14 1. Daily Catch and Bycatch Composition ofrhumboogie... 15 11. Daily Catch and Bycatch Composition ofterminator ;... 16 12. Daily Catch and Bycatch Composition ofellen Diane,............ 17 13. Daily Catch and Bycatch Composition ofjoyce Marie... 18 14. Daily Catch and Bycatch Composition ofmuktuk... 19 15. Comparison ofcatch and Bycatch ofnew Hampshire and Massachusetts Vessels 21 16. Monthly Comparison ofcatch and Bycatch " ".'".... 23 TABLES j 1 I;. 1. Comparative Catch Rates of Trawls.. 8 i'l; :,., 2
Introduction Beam trawling is a historic method of fishing that date back to the days of sail. The oldest of trawling methods, the name is due to the beam (or pole) used to keep the mouth of the net open. With the introduction ofpower-driven vessels the beam trawl was largely replaced by the otter trawl, which sweeps a larger area and is kept open by otter boards or "doors". Original beam trawls were very heavy (up to 7 tons) and, in some habitats, had a significant impact on the sea floor (Bergman and Hup, 1992). Over the last 2 years much lighter versions ofthe beam trawl have been developed and used in shrimp fisheries in Denmark, Belgium (Polet, 2), the Pacific coast ofnorth America (Love and Bishop, 22) and elsewhere. The shrimp fishery is in the northeast is a relatively clean fishery in terms ofbycatch, partly due to the recent requirement ofthe Nordmore grate in the nets. However any improvement in fishing methods in the Gulf of Maine that further reduce bycatch and bottom habitat impact will help maintain and improve stocks of commercial fish. Bottom trawl gear, without modification, is not very selective and catches a wide range of species. Approximately 15 years ago, a group of fishermen from Gloucester and Rockport, Massachusetts reported good results when they used beam trawls to catch both scallops and multi-species in areas where otter trawls couldn't be deployed. In one case a pair of22' beam trawls were towed from the FN Gypsy Rose and very high catches of shrimp were achieved. This alternate method was tried for just a single season and the results were not officially documented. An advantage claimed was a reduction in fuel bills and the fact that only one main towing warp was needed also reduced overall expenses. This study was initiated by a group of local fishermen who had learned that the performance ofbeam trawls in the Danish shrimp fishery appeared to be adaptable to the Gulf of Maine. Project Objectives Objectives of the project were to test the applicability of the beam trawl to the Gulf of Maine shrimp fisheries and to determine whether using a beam trawl instead of an otter trawl for shrimp fishing would reduce the amount ofbycatch caught. Participants Captain Bill Lee Melissa Hall, B.S. 25 pleasant St 16 Laurel Lake Rd Rockport MA 1966 Royalston MA 1368,oceanreporter@adelphia.net melis4ro@earthlink.net I[Allan Michael, Ph.D. ADM Associates 15 Field Rd!Magnolia MA 193 dmichaelra>.adelnhia.net + Seven participating vessels (appendix) 3
Methods A modified, lightweight version ofa standard beam trawl was constructed based on a design obtained from Danish fishery gear specialists Thomas Moth-Poulsen and Ullrich Hansen (Figures 1-3). The 2 ft high frame was lightweight aluminum and the bottoms ofthe skids were fitted with 6" x liz "polyurethane board to reduce digging. The 1.75-inch mesh net was fitted with a Nordmore grate with rolling stainless steel grate bars and used in regular shrimp fishing operations for 14 days. The net was in compliance with all state and federal fishing regulations. In January, 24, the beam trawl was installed on the FN Ocean Reporter captained by Bill Lee ofrockport. Hydraulic performance ofthe net was first evaluated using underwater video in test runs filmed in shallow, clear water in Ipswich Bay. An independent evaluation of the gear by a fisherman who was not otherwise involved in this study is included in the Appendix. During each experimental trawl, the location, depth, speed, and duration oftow were recorded on provided data sheets (see Appendix). On all but two occasions, a camera was mounted on the top ofthe beam to monitor the behavior of shrimp and other species entering or attempting to avoid the net. On one trip a small net was fixed to the top ofthe beam to determine whether shrimp were escaping over beam. After haul back, the catch was sorted and weighed and the bycatch also identified and weighed. Supplemental data was collected from 7 other participating fishing vessels towing the standard otter trawl currently used by the fleet (also fitted with a Nordmore grate). A biologist met with respective captains to provide them with data sheets and instructions on the collection ofdata. The biologist accompanied several of the vessels during trawling activity. These vessels operated in the same general area ofipswich Bay and, in many cases, on the same day(s) as the Ocean Reporter. Most tows were made in an area offrockport Massachusetts at depths ranging from 56 to 76 meters. Three vessels out ofhampton, New Hampshire reported their catch from a little further north on a total of eight days. Average tow duration and speed for the fleet using the otter trawl was 4.5 hrs at 2.5 knots. On the Ocean Reporter, the beam trawl was towed at speeds from 2.5 3. knots for an average of4.9 hours. During the last few tows with the beam trawl, some modifications were made which included removing the chain offthe sweep to minimize catch of groundfish, and letting more cable out so the gear could be towed faster. The data was summarized at ADM Associates, converted to catch-per-hour towed, and examined for differences in catch rates ofshrimp and bycatch. Bycatch was separated into three categories; groundfish (hake, skates, flounders etc), pelagic fish (herring, whiting) and others (invertebrates such as starfish, crabs and scallops). The complete data set is available from NEC. 4
Z 811a 2 Y"}; 11(1 -.,,", 'i''-7,11 p l' IDO II fo Figure 1: Dimensions ofthe Net 5
Bottom of the skidsfittedwith 6"x3"polyurethane to reduce bottomdigging and benthic disturbance.. Escape ventsafterthe funnelto reducefin fish. Rollmg stainless steelnordmore Gratebars to helpfin fishescapeand to keep shri.ltlprrom clogging the grate. light weigh aluminum andpolyurethane Notdmore Grate frame 114"lQ." BENT OVERTOPTOFIT.. ' WELDRtNG --';;-'-"":-"""':!ol LENGTH: 43id&xiS" BENTro Fb ji\" skid 7'-1/2" :x 8' Flat bar per kid 6' 114'! " 2" fiatbat pet d 4" SteeIpipe theleugthof{16 feet) Chain s,shac.kles a:ndrwb 16foOt tow bridle's OOchesijf6"x1l2" pdfyurtithait'e board... Figure 2: Low impact Shrimp Beam Trawl 16 Foot Beam Trawl for Shrimp 33' Footrope a111/3 1 7 / 8 inch inside mesh FN OCean Reporter Levin Marine Supply (58) 992-'477 December 23 6
Figure 3: Setting out beam trawl Figure 4: Beam trawl and Nordmore grate 7
Results Beam trawl versus otter trawl A total of8 fishing vessels participated in the study, sampled on 14 days (28 boat-days) for a total of 314.47 hours and provided 69 data sheets (examples in the Appendix). The average day included 4.5 hours of towing. The Ocean Reporter, using the beam trawl, caught 5,29 lbs of shrimp during the 14 days of trawling. Catch rate was 82.2 lbs shrimp per hour towed. Bycatch of fish and invertebrates was 723 lbs or 12% ofthe shrimp catch and was caught at a rate of 11.2 lbslhr. Other vessels towing the otter trawl were active on from 2-12 days and the totalcatches ranged from 1,968 to 12,423 lbs of shrimp (totai65,671ibs) with a fleet average rate of27.11bs /hr, Total bycatch varied from 7.7 to 2529lbs (total 7321 lbs) with a mean of28.4 lbslhr. Bycatch weight was 1.7% of the shrimp catch (Table 1). Mean catch per hour towed per day sampled is illustrated in Figures 5 and 6. Average weight of shrimp caughtlhr by the standard otter trawl was greater than the average weight of shrimp caught by the beam trawl on every day of sampling. One factor was the relative size of the beam trawl, which was 17 ft whereas the otter trawls used by the fleet ranged from 28 to 34 ft wide. Figure 5 shows the percent bycatch for the respective gear on each day that fishing was reported. There was considerable variation in percent bycatch for both the beam and otter trawls. On five days, bycatch was lower than the fleet average with the otter trawl, and on 6 six days, bycatch with the beam trawl was higher. The overall mean bycatch percent for the beam trawl was influenced by 3 individual days in January and February when bycatch was very high (24% 28%). On the remaining trips, bycatch with the beam trawl ranged from 5% to 14%. Table 1. Comparative Catch Rates of Trawls Average shrimp catch - otter = 278.4 lbslhr Average shrimp catch - beam = 73.71bslhr Average bycatch - otter =3 lbslhr (1.7%) Average bycatch - beam = 11.2 lbslhr (13.6%) \. 8
6 Shrimp Catch 5 'iii @. 397 " 4 " 1 366 1 CD 357.6 :: I... ::s 3 J: 226 23..8... CD 27.3 Co..c: o 'lu 2 1 1/21 212 219 211 2111 2/12 212 2124 2/27 3/1 3/2 3/3 3/4 3/5 otter traw I- MlI. Date beam traw I 4% 35% By-Catch 35% 3% 25% -c Gl u 2%... Gl a. 15% 1% 5% % 1/21 212 219 211 2111 2112 212 2/24 2/27 3/1 3/2 3/3 3/4 3/5.ottertrawl-MA Date.beam trawl Figure 5: Catch and Bycatch Comparison of Beam and Otter Trawls 9
Catch Rate Comparison BOO.,---------------=-------1 Cil g ' 6-\------ _ J :; 4+--------------- o 2 :I: 247.. 219 227 245 217 ell 2 C..c u n 'lii 13 11 o Boat Name Bycatch Comparison 2%,--------------------------------.., 15%+-------.c o 'lii o lj1%+--------- C ell ell Q. 5',,+---;;-=------ 16.9% % EJlenOiane JoyceMarie LadyBaine MarinaRose Muktuk RhumbOogie Terminator c:kean (NH) (NH) Boat Name (NH) Reporter Composition of Bycatch.groundfish % 12% -.-------------------'----------1 other speeles % 99% C pelagic.% 8%+-----------------.1-------1 7% 85%,., 6% +--------1.---""",._- I m e 4% +---:==-----1.-----1 6" 2% % Ellen Diane Joyce Marie LadyElaine Marina Rose Muktuk(NH) Rhumboogie (NH) (NH) Boat Name Tenninamr Ocean Reporter Figure 6: Catch, Bycatch and Bycatch Compostion of the Otter Trawl Fleet 1
Variation among boats -I... Catch and bycatch varied considerably among vessels and from day to day for each vessel (Figures 7-14). A very large number oftows would be needed to identify statistically significant differences, something beyond the scope ofthis development project. With the beam trawl shrimp catch rate varied from 16.6 lbs/hr on February 27 to a maximum of 133.3 lbs per hour on March 2, 24. Average catch rate of shrimp on otter trawl vessels for the study period ranged from 244 to 725 lbslhr. Daily variation of individual vessel catch is indicated by reports from the vessel Rhumboogie, which caught 6 lbslhr in 5 hours oftrawling on February 11, and 567lbslhr in 2.5 hours oftrawling on February 27. Variation in mean bycatch rates between vessels was significant and ranged from.4% to 16.9% (Figure 6). Most vessels also showed variation in bycatch rates from day to day, which may be due to areas fished, movement ofbycatch species or variations in the performance ofthe gear. Two vessels that reported very lowbycatch rate of.5% or less (Joyce Marie and Muktuk) fished on only two days. One other vessel, the Ellen Diane, had a low bycatch rate of from 2.2 to 3.9% over four days fishing. Four of the otter trawl vessels fished on ten days or more and only one ofthese (Terminator) had a fairly consistently low rate ofbycatch (1.8-9.%; average 5.1%). Variation in bycatch rate among other vessels that fished on at least ten days (Rhumboogie, Marina Rose, and Lady Elaine) was much higher, ranging from.1% to 41% (averages 12.6% to 14.9%). However, each ofthese vessels had at least four days when bycatch rates were less than 5%. On the days when bycatch rates were high, analysis of the catch composition showed that the main components of the bycatch on these occasions were pelagic species. These data suggest chance encounters with schooling species such as whiting and herring (see below). Bycatch with the beam trawl on the Ocean Reporter varied from 5.2 to 28.4% with an overall average of 12% over the 14 days fishing. This is in the range ofthe otter trawl vessels that fished on ten days or more. 11
Ocean Reporter 126 133 I wt shrimp/hr wt bycatchlhr I 111 62 75 "' 1 59 56 9,-- J2....4 6 6 6... I II I II iii 1/21 212 2J9 211 2/11 2/12 212 2124 2IZ7 3/1 3J2 3/3 3/4 315 1 6 6 9 6 Sample DOli. 35% Percent Bycatch Ocean Reporter 3% OR. 25% 24% 1% 5% % 9% 5% 14% "',. 13% ''. 12% 5% I I - 1% 1% V21 2/2 2/9 2/' 2/11 2/12 2/2 2/24 2/27 3/1 3/2 3/3 3/4 3/5 Sample Date. 12% Bycatch Distribution Ocean Reporter Bgroundfish % Bother species % []pelagic% 1% 8% 6% % 64% 68% 88/,.-", 79% 7." % % 4% - - r-r-' % % t % % % IJ 2% f-- r- r- f-- - - f-- % % 1I% % % [ % h " % % % %...,. l e...,. 1/21 212 219 211 2111 2112 212 2124 2127 3/1 3/2 313 3/4 3/5 SampleDali> 65%.- 61% 49».% 4g;,% 51{g.1o <.. Figure 7: Daily Catch and Bycatch Composition of Ocean Reporter 12
Bycatch Distribution Lady Elaine.groundfish % other species % o pelagic% 12% 1%... 81.8% C 8% CI> CI> a. 6% 86.4% 83.3/ 98.9% 4% 2% % 211 2113 2/27 1.1O.(J,O. 3/1 3/5 3/12 Sample Date Figure 8: Daily Catch and Bycatch Composition of Lady Elaine 13
Marina Rose wt shrimp/hr wt bycatch/hr 6 5.. @. -e 4.... " :I: 3. 2.s:: 1 39 358 357 SO<>,.. 1/21 2/2 216 219 211 2111 2/12 2117 2122 2/27 311 311 3112 Sample Dale 45% 4% 35% 3%.-C Ql 25% ụ. Ql a. 2% 15% 15% Percent Bycatch Marina Rose 41% 29/. 29% 25% 21% 1% 5% % 1/21 2/2 216 219 211 2/11 2112 2117 2J22 2/27 311 311 3112 Sample bate 12% Bycatch Distribution I groundfish % Marina Rose other species % Cpelagic.% I c -Ql ụ. 6% Ql a. 1% 8% """ =- =. 97% 97% 83% - - r'-- -,,% 81% 81% %,--- r--- - r--- - r--- 46%,--- -,--- f-- - - r- 4% 19 2% 2% r--- i r--- 4' 5 6% 3'lh 5 I. % % %........ IIIL l t ri 1121 2/2 216 219 211 2111 2112 2117 2122 2127 3/1 311 3112 Sample Date Figure 9: Daily Catch and Bycatch Composition of Marina Rose 14
6 Rhumboogie 5.. D 4 -e = "3: 39... 3 231 :I: :;; 185 a 2 15 15 "" u 1 443 215 211 2111 2112 2113 212 2124 2125 2127 3/1 313 3/5 SampleDate 45% 4% Percent Bycatch Rhumboogie 4/ 35% 3% C CD 25% = = 21% CD 19% Il.. 2% f--- I-- I---c- 17% r-= 15% I-- I-- I--- l- I-- 1% I-- I- I-- I-- t-- I- - - 5% I--- I-- I-- I---.-:- I- 1% 1% 1/. / % L, L.., '-r L, ' 215 211 2111 2112 2113 212 2124 2125. 2127 3/1 313 3/5 Sample Date 12% Bycatch Distribution groundfish % Rhumboogie other species % I Cpelagic % I C CD 1% 8% 1% 1% 1(l 1% 1% 1% 1/ 88% I-- f----- f----- r- - f----- f-- - e 6% I-- - r-- f----- - f----- r-- I-- - - CD Il.. 4% - - - - - - r-- - 2% - - - 2 r--.- % O'H O'Hi oo,j O'Hi 'lq' 'Al' ', 'lo'l 25 7<_ Ol 67% 5l!l9% r-- r-- '1 ',' 215 211 2111 2112 2113 212 2124 2125 2127 311 313 315 1/. I Sample Date Figure 1: Daily Catch and Bycatch Composition of Rhumboogie 15
5 444 Terminator I.WI shrimp/hr I.WI bycalch/hr I 4 329 @. -e. 3 261... 2!i7 24 225 :I: 192 i 2 163 167 156 146 o 1... 6... a... 14 5 7 7 6... 1/21 213 216 219 211 2111 2112 2113 2116 2117 2118 - - - SampleDat Percent Bycatch Terminator 3% -r------------------------------, 25% +-------------------------------1 2%+-------------------------------1 C Gl 15% +------------------------------1 Ql.. 9% 5% % 1121 213 216 219 211 2111 2112 2/13 2116 2117 2118 Sample Date Bycatch Distribution groundfish %.other species % Terminator lj pelagic % 1l%+-------------------------- 1 85% 8% 77% 8%+------- C 6% Gl 6% t----...,-----54'l1o----j 51% Gl.. 4% 66% 64% 2% % 2/3 2/6 2/9 2/1l 2/11 2/12 2/13 2/16 2/fl 2/16 Sample Date Figure 11: Daily Catch and Bycatch Composition of Terminator 16
Ellen Diane IIwt shrimplhr wt bycatchlhr 4 35 357.4 ;. " -e {!. 3 25 2 >: t. 15 ;; 1 5 2123 212' SampleDate 3/1 3/,.. Percent Bycatch Ellen Diane 3%.,-------------------------, 25% +------------------------ 2% +------------------------ c CD 15% +------------------------ D. 1% +------------------------ 5% +--o2%_--------'''-''1l'-------------_:b'i>_- 1 % 2/23 2/24 3/1 314 Sample Date.. C Bycatch Distribution.groundfish % Ellen Diane other species % 1%.,---------------------1 Clpelagic % BO% CD l:! 6% CD D. 4% 2%, %' 2/23 2/24 311 3/4 Sample Date Figure 12: Daily Catch and Bycatch Composition of Ellen Diane 17
4 Joyce Marie..., ;..., l- S ".. Q. o 3 2 1 327.2.5 1. 3/5 311 Samp&eDate 3% Percent Bycatch Joyce Marie 25% C QI QI D. 2% 15% 1% 5% %.2%._....6%..,.."..,., -.. 315 3r1d Sample D;:Ite 1% Bycatch Distribution Joyce Marie groundfish% other species% o pelagic / 8% C QI ụ.. Gl D. 6% 4% 4lJ.% 6.% 2% % 315 311 Sample Date.% Figure 13: Daily Catch and Bycatch Composition of Joyce Marie 18
'Kl!<lO. Muktuk.wt shrimp/hr.wt bycalch/hr 8 6 4 2 6 2.. 2/3 2/5 Sample Date 3% Percent Bycatch Muktuk -.. C CI1 U CI1 Q. 25% 2% 15% 1% 5% %.4% 5% 2/3 2/5 Sample Date 12% Bycatch Distribution Muktuk groundfish % otherspecies % Cpelagic% 1% 8% -C Gl Ụ. 6% CI1 Q. 4% 1.% 88.2% :.1-1.. 2% %.%.%.% 213 Sample Date 2/5 '. Figure 14: Daily Catch and Bycatch Composition of Muktuk 19
Composition ofbycatch The beam trawl had a consistently low bycatch ofpelagic species such as herring and whiting. The relative percentages ofgroundfish, other species (mostly invertebrates) and pelagics were 64.3%, 34.1% and 1.6% respectively. In contrast, overall composition ofbycatch for otter trawls was 14.5% groundfish, 2.9% other species, and 64.6% pelagics. In all cases when bycatch rates were above 15% with the otter trawl, more than 8% ofthe bycatch consisted ofpelagics. In these cases, the actual catch rates ofpelagics ranged from 75 to 6 lbs per hour. This suggests that the nets encountered schools ofeither whiting or herring and that marty fish were not able to escape through the opening above the Nordmore grate. Geographical Factors Four ofthe otter trawl vessels fished with the Ocean reporter (beam trawl) in a relatively small area just to the north ofrockport Massachusetts. Three vessels based in Hampton, New Hampshire, fished further north in Ipswich Bay. While these vessels fished on a total ofjust 8 days there was a marked difference in the bycatch rate and composition ofbycatch (Figure 15). Bycatch for the three New Hampshire vessels was extremely low and evenly divided between groundfish, other species and pelagics (approximately 3% each). The vessels, Ellen Diane, Joyce Marie and Muktuk, out of Hampton, New Hampshire, had bycatch rates of from.4% to 3.1%. Vessels out ofrockport, Massachusetts ranged from.5% to 16.5% with an overall average of 13.8%. There was insufficient data to determine whether the lower bycatch offthe New Hampshire coast was due to performance ofthe gear, or the habitat (bottom type) in the area trawled. The large numbers ofpelagics (whiting, herring), which were encountered in a few tows by the boats out ofrockport, were not found during the 55.4 hours oftrawling (total) by the New Hampshire vessels. Catch per hour towed was 243.91bslhr for the Rockport vessels and 422.11bs/hr for the New Hampshire vessels (Figure 15). The overall average for New Hampshire vessels was heavily influenced by the two days ofresults for Muktuk, which reported 9 lbs/hr on January 3 rd and 55 lbs/hr on January 5, 24. These were the two highest catch rates for any vessel in the study. 2
Comparison of MA and NH 5,.----------------------------, 4+------------ 422.1 "CI j.. :::l o J:.. Gl C..c o 3 +------------'-- 2 1 o otter - MA otter - NH beam 6. Bycatch Comparison 3% 25%.c-u 2% III U > m-c 15% QI Ụ.. QI. 1% 5% % 1.4% otter - MA otter - NH beam Figure 15: Comparison of Catch and Bycatch for New Hampshire and Massachusetts Vessels 21
Seasonal Trend Data was separated into 3 time periods to examine any seasonal trend in catch and bycatch rates. The first included the initial two weeks ofthe shrimp fishing season from January 19 to February 6,23. The second period included the remainder of the month offebruary and the last included the first two weeks in March. The catch per hour of shrimp for both the beam and otter trawls by the vessels operating out of Rockport was fairly consistent though the study period. Otter trawl vessels ranged from 34 lbslhr in the first time period (late January - early February) to 253 lbslhr in March. The beam trawl catch ranged from 12 to 7 lbslhr. In the first time period (January 1 - February 6) the only New Hampshire vessel that fished was Muktuk, which averaged 525 lbslhr for two days. In the remaining time period catch rates ofthe other two New Hampshire vessels, although slightly higher (274-37 lbs/hr)'did not differ significantly from those ef'the Rockport vessels. Bycatch rates were consistently higher throughout the time periods for the Rockport boats (28-39Ibs/hr) vs. the New Hampshire vessels (3.2-11.7 lbs/hr). The difference was due either to the habitat trawled, gear type, or the occurrence ofschool ofpelagics such as whiting and herring. 22
Seasonal Comparison of Shrimp Catch Ewl shrimp - MA (Otter) 8,...----------------------; Ewl shrimp (Beam) 725 Owl shrimp - NH(Oller) 7 lil g 'C ; I-... 6 5 4 ::J :I: 3... CIl Cl. s: J:l IV 2 1 34 37.43 1/19-2/6 2/9-2/27 Dates 3/1 3/12 Seasonal Comparison of Bycatch wl bycatch -MA (Oller) 5,----------------------1.wl bycatch (Beam) Owl bycatch -NH (Oller) 39 4 +-------------------'-----_rr ----- l lil J:I '= 'C 3 CIl I... ::J :I: 2... CIl Cl..t= J:l IV 1 o 1/19-2/6 2/9-2/27 3/1-3/12 Dates Figure 16: Monthly Comparison of Catch and Bycatch 23
Discussion This was a Northeast Consortium development project (maximum $25,) and funding only allowed 14 days oftesting with the beam trawl. There was therefore very limited opportunity to make adjustments to improve the catch rate. Some minor modifications were made such as reducing the weight ofthe sweep, which was too heavy in the initial stages. Other variations that could be tried in the future are to raise the beam 2 inches to reduce the groundfish bycatch, and towing at faster speeds (up to 4 kts). The gear is easily adaptable to small boats and could be an alternate fishing method for scallop boats since only a single wire is required. Towing with a single wire means more maneuverability, allowing vessels to trawl closer to hard bottom and areas where fixed gear prevents otter trawl activity. The opening ofthe net remains constant in size during turns and trawling performance is better in soft muddy bottoms (Rose et al. 22). Significant cost reductions (compared to trawling) include the cost ofthe gear itself. There are no doors, the net is smaller and only one wire is needed. Vessels having restricted warp capacity can fish in deeper waters since only about halfthe amount ofwarp is needed compared to gear where doors are used. Fuel costs will be significantly lower since the horsepower required to tow this light modified beam across the surface is much less than that needed to pull heavy doors which sink into the bottom. In one period ofthree days, the Ocean Reporter used 16 gallons offuel while beam trawling, whereas historical records for this boat show typical usage of7-8 gallons/day towing an otter trawl. ' One issue that was not addressed in this project is the relative 'bottom disturbance of a lightweight beam trawl, such as built for this study, versus the otter trawl(s) currently used by the fleet. This would take a separate project specifically designed for that purpose, Partnerships There was a high level of interest among those fishermen from the area who are involved in shrimp fishing. Seven vessels were involved in the collection of data for shrimp fishing with otter trawls for comparison. All who participated will receive a summary version of the results ofthis study. References Bergman, MJ.N. and M. Hup. 1992. Direct effects of beam trawling on macro-fauna in a sandy sediment in the North Sea. ICES Journal of marine Science. 49:5-11 Love, D. and G. Bishop. 22. Report to the Board of Fisheries. Southeast Alaska beam trawl fisheries. Regional Information Report No. 112-45 Polet, H. Codend and whole trawl selectivity ofa shrimp beam trawl used in the North Sea. 2. Fisheries Research 48: 167-183 24
Rose, c., A. Carr, R. Ferro, R. Fonteyne, and P. MacMullen. 22. Unpublished manuscript. The characteristics and function of commercial fishing gears;.how these relate to their effects on seafloor habitats and the pursuit ofways to minimize effects.. Manuscript submitted to the NOAAlUSGS Symposium on Effects of Fishing Activities on Benthic Habitats, Tampa; Florida, November 22..'., " ) f Appendix List ofparticipating fishermen and vessels Reported catch by vessel Independent evaluation ofbeam trawl Examples of daily trip reports..r,. Participating Fishing Vessels: FN Ellen Diane, Capt. Dave Goethel FN Lady Elaine, Capt. Dennis O'Connell FN Muktuk, Capt. Mike Pike FN Marina Rose, Capt. Bob Fisher FN Rhumboogie, Capt. Jason Pollison EN Special K, Capt. Jack Ketchopulos FN Terminator, Capt. Paul Theriault 25