Seychelles tuna bulletin: first semester 1999
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. Spmetimes there is a delay 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 revi¬sion (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 1998 is now 252,757 mt. This catch was achieved by an average of 51 vessels active per month. The total effort recorded for the purse seine fleet during 1998 was 15,448 fishing days, thus giving a mean catch rate of 16.36 mt/fishing day. The highest recorded catch so far was in 1995 when 307,135 mt of tuna were caught_ The 1995 catch was the result of an average of 49 vessels active per month at an annual CPUE of 21.27 mt/fishing day. The highest annual CPUE on record was obtained in 1992 at 22.27 mt/fishing day. The catch within the first semester of 1999, was 129,881 mt. This comprised 39,208 t (30%) yellowfin (Thunnus albacares) and 78,417 t (60%) skipjack (Katsuwonus pelamis). The remaining 12,256 t (10%) was mainly bigeye (Thunnus obesus) and albacore (Thunnus alalunga). This compares with the catch within the first semester of 1998 when some 32,359 t (25%) of yellowfin was caught, together with 81,983 t (64%) of skipjack and 14,395 t (11%) of bigeye and albacore. Some 7,068 fishing days were recorded in the first semester of 1999 compared to 7,578 days for the equivalent period of 1998. The ef¬fort recorded for the first semester of 1999 are 510 days (7%) below that recorded for the same period in 1998. 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 de¬cide into which group fish should be placed. They may be biased. The CPUE within the first semester of 1999 was 18.38 mt/fishing day compared to 16.99 t/fishing day in the equivalent semester of the previous year. It should be noted that the figures in Table 3 (Purse seiner tranship¬ment statistics by harbour of transhipment) represent the tranship¬ments 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 1998 stands at 151,592 mt, representing 60% of the total catch. Within the first semester of 1999 transhipment in Port Victoria to¬talled 84,256 nu, (65% of the total catch), compared to 45,464 mt (35% of the total catch), for the same period last year. This dramatic increase in the 1999 figures is due to purse seiners fishing more in the WIO during the first semester of 1999. Purse seine fishing was concentrated mostly around the western part of the Seychelles EEZ and in the Mozambique Channel during the first semester of 1999, where fishing is usually good in the second quarter of the year. In 1998, during that period some vessels were fishing further East of the 80° meridian. Longliner activity PRINCIPAL POINTS: 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. 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. Statistics published for 1998 relate to only 122 logbooks received at the date of publication of this bulletin. And a total of 198 licences were issued for that year. This represents a reporting rate of 62%. For the first semester of 1999, 38 logbooks have been received for the 68 li¬cences issued. These statistics will be revised as more data becomes available. Analysis of data collected to date shows that: For the first semester of 1999, longliner activites were concentrated in January, February, March and April. This is a similar pattern to those observed in the past years. A fishing effort of 5.8 million hooks for a total catch of 2,087 mt has been reported for the first semester of 1999. The mean CPUE for the same period was 0.36 t/1000 hooks. The mean CPUE by nationality was: 0.43 01000 hooks for the French, 0.43 t/I000 hooks for the Japanese, 0.41 t/1000 hooks for the South Koreans, and 0.31 t./1000 hooks for the Taiwanese. For this same period, yellowfin (Thunnus albacares) comprised 42% of the total catch, bigeye (Thunnus obesus) comprised 47% and other species (billfishes) comprised 11%. The French longliners targeted billfishes (74% of their total catch).
| Other Authors: | |
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| Format: | Other biblioteca |
| Language: | English |
| Published: |
1999
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| Subjects: | Purse seiners, Catch statistics, Tuna fisheries, |
| Online Access: | http://hdl.handle.net/1834/5197 http://hdl.handle.net/1834/5196 |
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