| Resumo: |
Data used to generate the tables and figures presented here are based on daily catch and effort forms (logbooks) returned from fishing vessels which are licensed to fish in the Seychelles EEZ. Sometimes there is a delay in these being received at the SFA, especially during and just after the second quarter of the year when most vessels are fishing in the Mozambique Channel. Readers should be aware that many of the figures presented here (especially the most recent) are subject to revision (usually upwards) as more data become available. The date upon which the SFA database was closed prior to the generation of the statistical tables is shown at the head of each table. Purse seiners. PRINCIPAL POINTS: The total purse seine tuna catch for the Western Indian Ocean in 1996 was 265,658 t. This catch was achieved by an average of 49 vessels licensed per month. The total effort recorded for the purse seine fleet during 1996 was 12,948 fishing days, thus giving a mean catch rate of 20.52 t/fishing day. The highest recorded catch so far was in 1995 when 307,135 t of tuna were caught. The 1995 catch was the result of an average of 52 vessels licensed per month at an annual CPUE of 21.27 t/fishing day. The highest annual CPUE on record was 1992 at 22.27 tlfishing day. The catch within the fourth quarter of 1997, was 76,534 t. This comprised of 12,653 t (16%) yellomifin (Thunnus albacares) and 56,253 t (74%) skipjack (Kaisutvonus pelamis). The remaining 7,625 t (10%) was mainly big eye (Thunnus obesus) and albacore (Thunnus alalunga). This compares with the catch within the fourth quarter of 1996 when some 23,101 t (27%) of yellowfm was caught, together with 54,149 t (64%) of skipjack and 7,894 t (9%) of bigeye and albacore. Some 3,747 days were fished in the fourth quarter of 1997 compared to 3,501 days for the equivalent period of 1996. The effort recorded for the fourth quarter of 1997 are some 246 days above that recorded for the same period in 1996. Considering that not all logbooks for the period under review have been received at the SFA, this difference between the two years is expected to increase further once all logbooks have been collected and processed. Readers should be well aware that the catch compositions given here are NOT based on scientific sampling but on the assessment of the fishermen who write the daily catch and effort reports and who decide into which group fish should be placed. They may be biased. The CPUE within the fourth quarter of 1997 was 20.43 t/fishing day compared to 24.32 tifishing day in the equivalent quarter of the previous year. It should be noted that the figures in Table 3 (Purse seiner transhipment statistics by harbour of transhipment) represent the transhipments of vessels whose trips ENDED in the month indicated and NOT the actual month of physical transhipment of the catch. Transhipments through Victoria for the whole of 1996 was 163,657 t compared to 185,489 t in 1995. The overall decrease in transhipment in Port Victoria during 1996 is the result of the lower catch during 1996 rather than a decrease in importance of Port Victoria. This is reflected in the total transhipped in Port Victoria as a function of the total transhipped through all ports, whereby 61% of the total tranship-ment during 1996 took place in Port Victoria, as has been the case for the last two years. Within the fourth quarter transhipment in Port Victoria totalled 67,669 t. This is an increase of 14 % compared to the figures obtained in the fourth quarter of 1996, when 59,496 t of tuna were transhipped. During the fourth quarter of 1997 most fish were caught in the Somali Basin unlike during the fourth quarter of 1996. Whilst the major fishing grounds exploited in the fourth quarter of 1997 are similar to those exploited in the same period of 1996, catches of yellowfin around the Chagos Archipelago was disappointingly low. Longliner activity Readers should be aware that these statistics only represent a small sample of longliner activity in the WIO because: Not all longliners fishing in the WIO have a licence to fish in the Seychelles EEZ and therefore are under no obligation to report to SFA. Not all those with a Seychelles licence provide daily log sheets especially the Taiwanese and the Koreans.
|
