Seychelles tuna bulletin : first quarter 1996

Abstract

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 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 1995 is now 307,796t. This is the highest catch reported since record began. The previous highest recorded catch was 280,114t in 1994. However, while the 1994 catch was the product of an average of 51 vessels licensed per month at an annual CPUE of 20.21t/fishing day, the 1995 catch was the result of an average of 52 vessels licensed per month at an annual CPUE of 21.32t/fishing day. The highest annual CPUE on record was recorded in 1992 at 22.27t/fishing day. - Some 2,341 days were fished in the first quarter of 1996 compared to 3,888 days in the equivalent quarter of 1995. The effort recorded for the first quarter of 1996 are some 1,547 days short of that recorded for the same period in 1995. However, we expect that this figure will increase once all log books for fishing activities in the first quarter are received at the SFA. - The catch within the first quarter of 1996, based on the available logbooks, was 37,546t. This comprised of 16,762t (45%) yellow fin (Thunnus albacares) and 15,243t (41%) skipjack (Katsuwonus pelamis). The remaining 5,541t (14%) was mainly big eye (Thunnus obesus) and albacore (Thunnus alalunga). This compares with the catch within the first quarter of 1995 when some 21,193 t (32%) of yellowfin was caught, together with 42,368t (57%) of skipjack and 8,180t (11%) of bigeye and albacore. Yellowfin tuna has in the first quarter of this year been more prominent in the catch than in the past. - 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 1996 was 16.04t/fishing day compared to 19.22t/fishing day in the equivalent quarter of the previous year. - It should be noted that the figures in Table 3 (Purse seiner transshipment statistics by harbour of transshipment) represent the transshipments of vessels whose trips ENDED in the month indicated and NOT the actual month of physical transshipment of the catch. - Transshipments through Victoria amounted to 46,232t in the first quarter of 1996. This is a decrease of almost 4% compared to the figures obtained in the first quarter of 1995, when 44,627t of tuna were transshipped. - During the first quarter of 1996 most of the fishing activities were stretched between the extreme south-east of the Seychelles EEZ and the Chagos Archipelago, whereas, during the first quarter of 1995 most fish were caught in and around the Seychelles EEZ. Longliners Readers should be aware that these statistics only represent a small sample of longliner activity in the W10 because: - Not all longliners fishing in the WIO have a license to fish in the Seychelles EEZ and therefore are under no obligation to report to the SFA. - Not all those with a Seychelles license provide daily log sheets especially the Taiwanese and the South Korean vessels. - Some distant water fishing nations (DWFN) provide SFA with log sheets covering their activity in the whole of the Indian Ocean whilst others confine their reports to the Seychelles EEZ. At the time of generating the tables only 43 logbooks had been received from 298 vessels which were licensed to fish in the Seychelles EEZ in 1995. For the first quarter of 1996, 21 logbooks were returned, out of 141 licenses issued. This underlines the poor and very slow reporting rate of longliners in general. Analysis of the data available for the first three months of 1996 shows that: - During the first three months of 1996 most of the longliner fishing activities were outside the north-eastern boundary of the Seychelles EEZ (Map 3). Unlike in 1995, more sets were made in the area between 10'N and the equator and between longitude 60°E and 50°E. - A total catch of 682 tones from a total effort of 848,873 hooks was recorded for the first quarter of 1996 compared to a total catch of 51 tones from a total effort of 385,596 hooks in the same quarter of 1995. The mean CPUE recorded for the first quarter of 1996 was 0.80 t/1000 hooks compared to 0.13 t/1000 hooks in the equivalent quarter of the previous year. At the time of generating the tables no daily logs had been received from the South Korean and Taiwanese fleet for 1996. - Yellowfin (Thunnus albacares) continues to dominate the catch of the longliners, it accounted for 73% of the total catch whilst bigeye (Thunnus obesus) comprised of only 18% and the remaining 9% being made up of other species.