Data/hora: 04/06/2024 02:18:43

Provedor de dados: | 20
País: | Belgium
Título: | Seychelles tuna bulletin : first quarter 1997
Data: | 2013-11-02
Ano: | 1997
Palavras-chave: | Purse seiners; Catch statistics; Tuna fisheries.
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 del{--y in these being received at 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 is now 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 obtained in 1992 at 22.27 t/fishing day. The catch within the first quarter of 1997, was 48,132 t. This comprised of 18,030 t (37%) yellowfin (Thunnus albacares) and 25,747 t (54%) skipjack (Katsuwonus pelarnis). The remaining 4,355 t (9%) was mainly big eye (Thunnus obelus) and albacore (Thunnus alalunga). This compares with the catch within the first quarter of 1996 when some 19,637 t (39%) of yellowfin was caught, together with 23,116 t (46%) of skipjack and 7,047 t (15%) of bigeye and albacore. • Some 2,505 days were fished in the first quarter of 1997 compared to 3,307 days for the equivalent period of 1996. The effort recorded for the first quarter of 1997 are some 802 days short of that recorded for the same period in 1996. However, this difference between the two years is expected to decrease once all logbooks, for the period under review, 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 first quarter of 1997 was 19.21 tifishing day compared to 15.06 t/fishing 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 164,169 t compared to 185,489 t in 1995. This is a 12% decrease over the 1995 figure. This decrease is as a result of the lower catch during 1996 rather than a decrease in importance of Port Victoria. This is reflected in the the total transhipped in Port Victoria as a function of the total transhipped through all ports, whereby 61% of the total transhipment during 1996 took place in Port Victoria, as has been the case for the last two years. During the first quarter transhipment in Port Victoria totalled 60,497 t this is an increase of 33% compared to the figures obtained in the first quarter of 1996, when 45,360 t of tuna were transhipped. Based on the data available, we can see that fishing activities in the first quarter of 1997 were concentrated in and around the Seychelles EEZ. Some activities were also recorded between the Seychelles EEZ and the Chagos Archipelago. Unlike the previous year very little fishing took place in the Mozambique Channel in the first three months of 1997. Once all logbooks have been gathered and processed a more meaningful comparison of fishing grounds exploited in the relevent quaters of the two years may be obtained since the data being used at present does not cover the activities of all vessels during the first quarter of 1997. Longliners 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. Some Distant Water Fishing Nations (DWFN) provide SFA with log sheets covering their activity in the whole Indian Ocean while others confine their reports to the Seychelles EEZ. The statistics for 1996 are related to only 56 logbooks received at the date of publication of this bulletin. 21 logbooks were received from the Japanese, 16 logbooks were received from the Taiwanese, 11 logbooks were received from the French and 8 logbooks were received from the South Koreans. A total of 342 licences were issued in 1996, compared to 292 licences issued for 1995. For the first quarter of 1997, only 1 logbook has been received to date and 113 licences has been issued. This underlines the poor and very slow reporting rate of longliners in general. When more data will be available, these statistics will be revised. Analysis of data collected to date show that: Longliner activity was concentrated at the beginning or end of the year (first and last quarter) with little or no fishing from May to. August. A fishing effort of 5,147,413 hooks for a total catch of 2,246 MT has been reported for 1996. The mean CPUE for the same period was 0.44 t/1000 hooks. The mean CPUE by nationality was: 0.63 t/1000 hooks for the French, 0.53 t/1000 hooks for the Japanese 0.31 t/1000 hooks for the South Koreans and 0.21 t/1000 hooks for the Taiwanese fleet. Yellowfin (Thunnus albacores) comprised 53% of the total catch for 1996, Bigeye (Thunnus obesus) comprised 32% and other species (billfishes) comprised 15%. The French longliners targeted billfishes (57% of their total catch). The principal fishing areas for the first quarter of 1997 were located: at the central part inside and the south-eastern part inside and outside of the Seychelles EEZ.
Tipo: | Other
Idioma: | Inglês
Identificador: | http://hdl.handle.net/1834/5211
Formato: | 40
Fonte: | http://creativecommons.org/licenses/by-nc/3.0/