SCIENTIFIC COUNCIL - JANUARY 1998

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1 OT TO 13E CITED WITHOUT PRIOR REFERECE TO THE AUTHOR(S) orthwest Atlantic Fisheries Organization Serial o AFO SCR Doc. 98/1 SCIETIFIC COUCIL - JAUARY 1998 Catch Statistics and Biological Sampling From the orwegian Fishery in AFO in 1995 (Revised) and 1996 (Preliminary)' by Kjcll Harald edreaas Institute of Marine Research P.O.Box 187, 524 Bergen; orway Abstract Two sources of fishery statistics are available from the orwegian fishery outside the orwegian EEZ. These are the Statlant 21A landings statistics and the log-books written by the skipper during fishing. The landings statistics are considered to give more exact weights whereas the log-books are more precise with regards to tishing locations. The orwegian trawlers fishing for Greenland halibut concentrated all their effort to AFO area 1D in 1996 with a slight increase in tons/hour compared to the year before. This was also the first year orwegian longline vessels tried and succeeded in a commercial Greenland halibut fishery at West-Greenland. Length measurements of the trawl and longline catches, made by the fishermen themselves, are given. Revised catch figures for Greenland halibut taken by orwegian vessels in Subarea in are presented. Introduction In addition to whaling, orway has long traditions in fishing cod, Atlantic halibut, Greenland halibut and shrimp in the different AFO areas. Information about fishing effort and age and length composition of the catches have regrettably often been scarce. Economically it may also be expensive to send people on board the vessels for biological sampling. The present paper informs about the orwegian data sources for catch statistics and the length measurements taken of the orwegian catches of Greenland halibut in the AFO area in Fishery statistics Materials And Methods The official orwegian fishery statistics are based on the Statlant 21A statistics, expressed in tons live weight equivalent of the landings. Statlant 21A is based on information from the orwegian sales unions. Another source of fishery statistics comes from the log-books obligatory for the vessels to write daily (longline) or for each trawl haul. The log-book statistic is generally more precise with regard to the information about the geographical location from which the catch was taken. The catch statistics presented in this paper arc from a scientific point of view considered the most accurate to be used for assessment purposes. The log-book statistics also provide us with data on CPUE. 'A time-series of orwegian trawler CPUE has been used in previous assessments and is updated by the present revised 1995 data and the new preliminary 1996 data. This SCR Document is an upgrade of SC Working Paper o. 97/14, which was issued at the 4-19 June 1997 Meeting of the Scientific Council.

2 2 Biological sampling The biological sampling from the orwegian fishery in AFO in 1996 is restricted to Greenland halibut in AFO Division ID. All the samples (only length) were taken by the fishermen themselves according to instructions given by the institute of Marine Research in advance. Altogether 7 length-samples were provided by one trawler catching approximately 2% (323 tons) of the total orwegian trawl catch in 1996 (1586 tons). The samples were spread out in time (1 Oct -1 ov 96). Two orwegian longliners participated in the orwegian fishery for Greenland halibut at West-Greenland in 1996, catching 27 tons. One of these vessels provided us with 1 length samples spread out in time (1 Oct - 1 ov 96). Data (in tons) on fish by-catches in the orwegian shrimp fishery at Flemish Cap should be available from the observers on board which report to AFO with copy to the orwegian Directorate of Fisheries. Data on bycatches are also entered into the official log-books and stored on paper. The importance of by-catch statistics for proper fish stock management is clear, and although no information is currently presented, proper by-catch statistics (preferably on length by species in addition to quantity) should be prepared for meetings to come. Fishery Statistics Results Table 1-2 shows the orwegian trawl catches and CPUE values by AFO-area as revised figures for 1995 and preliminary figures for Table 3 shows the orwegian longline catches in The redtish trawl catch of 3 tons in 3M in 1995 and the Greenland halibut longline catch of 1 ton in 3M in 1996 were only reported in the landings statistics and not in the log-books. The orwegian trawlers fishing for Greenland halibut concentrated all their effort to AFO area 1 D in 1996 with a slight increase in tons/hour compared to the year before. This was also the first year orwegian longline vessels tried and succeeded in a commercial Greenland halibut fishery at West-Greenland. Table 1. Revised orwegian trawl catches by species and AFO-area in The figures for Greenland halibut and cod are from log-books whereas the redtish and shrimp figures are the Statlant 21A landings statistics. Species orwegian statist. area AFO-area Catch Fishing months CPUE ') Greenland halibut 11 tons /fish day tons/hours trawling tons/haul 67 IC 234 Aug-Oc t ID 2244 Aug-ov and 68 IC-D 2478 Aug-ov ] 3M 1 Oct Cod 68 ID 6 Oct Sebastes sp 81 3M 3 Shrimp 81 3M 942 Jan-Dec ) From log-books.

3 3 Table 2. Preliminary orwegian trawl catches by species and AFO-area in The figures for Greenland halibut and cod are from log-hooks whereas the shrimp figures are the Stallant 2IA landings statistics. Species orwegian statist. area AFO-area Catch Fishing months CPUE li Greenland tons tons/hours tons/haul halibut I) /fish day trawling 67 IC 68 ID 1586 Aug-ov and 68 1C-D 1586 Aug-ov Cod I) 68 ID 23 Oct Shrimp 81 3M 5643 Apr-Dec " From log-books. Table 3. Preliminary orwegian longline catches by species and AFO-area in Species orwegian statist. area AFO-area Catch Fishing months CPUIT Greenland halibut tons /fish day tons/hours trawling tons/haul. 67 " IC 68 I) 1D 27 July-Oct n.a. n.a. n.a. 81 2) 3M 1 n.a_ n.a. n.a. Skates ') 68 ID 2 Oct n.a. n.a. n.a. " From log-books. 2) From landings statistics, Statlant 21A (information from the orwegian sales unions). n.a. - not available Revision of orwegian catch.statistics of Greenland halibut in Subarea. According to orwegian landings statistics (Statlant 21A) the correct catch figures for Greenland halibut taken by orwegian vessels in Subarea should be: 1989: tons 199: 5,668 tons 1991: 3,566 tons 1992: tons 1993: 373 tons The big difference between these figures and those at present seen in the AFO statistics for 199 is due to double reporting caused by Canada/Greenland reporting catches taken by orwegian vessels during a jointventure project.

4 4 state According to international conventions the responsibility of statistical catch reporting belongs to the flag Biological sampling of Greenland halibut in AB Subarea 1 in 1996 Length measurements of the trawl and longline catches, made by the fishermen themselves, are given in Table 4 (trawl) and Table 5 (longline). The frequency distributions (common and cumulative) are shown in Figure 1 for illustrating the differences between the two gears. Table 4. Length measurements of Greenland halibut from seven trawl hauls at West-Greenland in TRAWL St.no. 1 St.no. 2 St.no. 3 St.no. 4 St.no. 5 St.no. 6 St.no, 7 Total % Cifinul _Date Depth 143in I m 115m 12m 11in Position W564 W575 W564 W5717 W562 W575 W57 Catch 33 kg 225 kg 3 kg 24 kg 3975 kg 315 kg 33 kg Length I I SUM _

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6 .35.X c.2 a> g.15 LL.1.5. CO CO CD - r- c9 co co CD.9.8 ri.7 1:1).6 g g.1. M Trawl-freq. Line-f req. - Traw I-currul. X Line-currul. Length-groups Figure 1. Length frequency distribution and cumulative frequency of Greenland halibut caught by trawl. (squares) and longline (stars and crosses). The curves are based on samples taken by the fishermen during die orwegian fishery at West-Greenland in 1996.