Statistics of the European Union and associated flags purse seine fishing fleet targeting tropical tunas in the Indian Ocean

Transcription

1 IOTC-2014-WPTT16-13 Statistics of the European Union and associated flags purse seine fishing fleet targeting tropical tunas in the Indian Ocean E Chassot, A. Delgado de Molina, C Assan, J Lucas, P Dewals, P Cauquil, JJ Areso, DM Rahombanjanahary, M Soto L Floch SUMMARY In, the European and associated flags (EAF) purse seine fishing fleet of the Indian Ocean was composed of 35 vessels of individual capacity >800 t, which all represented a total carrying capacity >45,000 t of tuna. The total cumulated nominal effort exerted during the year was about 10,000 and 8,000 fishing and searching days, respectively. The EAF purse seiners cumulated a total of more than 9,300 fishing sets, with 80% made on FAD-associated schools (FAD) and 20% realised on free-swwiming schools (FSC). The total annual landings of the principal market tunas by the French purse seine fishing fleet increased by 20% between 2012 and and reached more than 270,000 t. The landings were composed of about 49%, 42%, and 9% yellowfin, skipjack, and bigeye, respectively. Total catches on FAD-associated schools increased from 150,000 t in 2012 to about 225,000 t in (+50%) while catches on FSC substantially decreased from 78,000 t to about 45,000 t (-43%). The percentage of yellowfin in the FAD catch has steadily increased over the recent years from about 25% during to more than 40% in The catch of skipjack per positive set on FADassociated schools has strongly decreased since the early 2000s, from >30 t set 1 in to <17 t 1 in By contrast, the catch of yellowfin per FAD positive set has increased from low values of about 7.3 t set 1 during to almost 15 t set 1 in. The catch of yellowfin in free-swimming schools was at high levels (>30 t set 1 ) in KEYWORDS: fish aggregating device, Katsuwonus pelamis, Thunnus albacares, Thunnus obesus Institut de Recherche pour le Développement, UMR 212 EME (IRD/Ifremer/UM2), BP570, Victoria, SEYCHELLES Instituto Español de Oceanografia, PO Box 1373, S/C Tenerife, SPAIN Seychelles Fishing Authority, BP 570, Victoria, SEYCHELLES IRD, UMR 212 EME (IRD/Ifremer/UM2), Avenue Jean Monnet, BP 171, Sète Cedex, FRANCE Spanish Fisheries Office, P.O.B 497, Victoria, SEYCHELLES Unité Statistique Thonière d Antsiranana, Rue du Quai, Ville Basse, BP523, Antsiranana, MADAGASCAR IEO, Subdirección General de Investigación, Corazon de Maria, 8, Madrid, SPAIN 1

2 Acknowledgments We thank ORTHONGEL, ANABAC and OPAGAC and all past and current personnel for helpful assistance in data collection and management. We are particularly grateful to Renaud Pianet, Viveca Nordstrøm and Alain Fonteneau for their dedication to the monitoring of tropical tuna fisheries and their support to the Observatoire Thonier. Sampling operations were conducted by the teams of J Esparon and A Tyrant. This work was financed by the European Data Collection Framework(DCF, Reg 199/2008 and 665/2008) and supported by the French Direction des Pêches Maritimes et de l Aquaculture (DPMA) and the Spanish Fisheries Department. Special thanks to L Kell (ICCAT) for providing the L A TEX template.

3 1. Figures t t t t t >2000 t Number of vessels by size category Figure 1: Fishing capacity of the European Union and associated flags purse seine fishing fleet in the Indian Ocean. Annual changes in the number of purse seiners by size category (barplots) and total carrying capacity (solid line with circles) during Capacity was weighted by the vessel-specific proportion of the year at sea (in months). The vessel size category (t) was computed as 0.7 times the capacity expressed in m 3

4 60 Unweighted Weighted 50 Number of vessels Figure 2: Number of active vessels in the European and associated flags purse seine fleet. Annual total number of French purse seiners in the Indian Ocean during Weighted indicates that the number of purse seiners was weighted by the vessel-specific proportion of the year at sea (in months)

5 15 Fishing days Searching days Fishing effort (x1000 d) Figure 3: Changes in nominal effort over time. Annual total number of fishing and searching days for the European Union and associated flags purse seine fishing fleet in the Indian Ocean during 1981-

6 20 N 10 N 0 10 S 20 S 54 d 30 S 40 E 60 E 80 E Figure 4: Fishing grounds. Spatial distribution of fishing effort (in searching days) of the European Union and associated flags purse seine fishing fleet in 2012

7 Spatial occupancy Total With # sets > 1 With catch > 0 With effort > 1 d Figure 5: Changes in spatial extent of the fishery over time Annual number of 1-degree squares explored by the European and associated flags purse seine fishing fleet during 1981-

8 Number of sets FAD associated schools Free swimming schools Figure 6: Fishing operations. Annual number of fishing sets made by the European Union and associated flags purse seine fishing fleet on FAD-associated and free-swimming schools during Line with solid circles indicates the percentage of sets made on FAD-associated schools over free-swimming schools. Grey solid line indicates the 50% value

9 Catch (x1000 t) BET SKJ YFT Figure 7: Total fishery production. Catch by species of the European Union and associated flags purse seine fishing fleet during Catch (x 1000t) BET SKJ YFT (a) Catch (x 1000t) BET SKJ YFT (b) Figure 8: Fishery production by major fishing mode. Catch by species of the European Union and associated flags purse seine fishing fleet on (a) FAD-associated and (b) free-swimming schools during 1981-

10 20 N 10 N 0 10 S 20 S YFT SKJ 6000 t BET 30 S 30 E 50 E 70 E 90 E Figure 9: Spatial distribution of tuna catches of the European Union and associated flags purse seine fishing fleet in

11 20 N 10 N 0 10 S 20 S YFT SKJ 6000 t BET 30 S 30 E 50 E 70 E 90 E Figure 10: Spatial distribution of tuna catches of the European Union and associated flags purse seine fishing fleet made on FAD-associated schools in 20 N 10 N 0 10 S 20 S YFT SKJ 4000 t BET 30 S 30 E 50 E 70 E 90 E Figure 11: Spatial distribution of tuna catches of the European Union and associated flags purse seine fishing fleet made on FSC-associated schools in

12 1.0 (a) 1.0 (b) Number of sets per searching day Number of sets per searching day (c) Total Skipjack Yellowfin Bigeye (d) Total Skipjack Yellowfin Bigeye Catch (t) per positive set Catch (t) per positive set Figure 12: (a-b) Annual number of sets per searching day and (c-d) catch per positive set on (left panel) FAD-associated and (right panel) free-swimming schools for the European Union and associated flags purse seine fishing fleet in the Indian Ocean during 1981-

13 30 Total Skipjack Yellowfin Bigeye (a) 20 Total Yellowfin Skipjack Bigeye (b) Catch per unit effort (t d 1 ) Catch per unit effort (t d 1 ) Figure 13: Annual catch rates (in t per searching day) of the European Union and associated flags purse seine fishing fleet on (a) FAD-associated and (b) free-swimming schools in the Indian Ocean during 1981-

14 YFT BET SKJ FAD Numbers (x1000) Numbers (x1000) Numbers (x1000) FSC Numbers (x1000) Numbers (x1000) Numbers (x1000) ALL Numbers (x1000) Numbers (x1000) Numbers (x1000) Figure 14: Size structure of the catch. Size distribution (in numbers) of the species-specific catch for the European Union and associated flags purse seine fishing fleet in (red line) and for an average year representing the period (black line)

15 YFT BET SKJ FAD Biomass (x1000 t) Biomass (x1000 t) Biomass (x1000 t) FSC Biomass (x1000 t) Biomass (x1000 t) Biomass (x1000 t) ALL Biomass (x1000 t) Biomass (x1000 t) Biomass (x1000 t) Figure 15: Size structure of the catch. Size distribution (in biomass) of the species-specific catch for the European Union and associated flags purse seine fishing fleet in (red line) and for an average year representing the period (black line)

16 50 40 FSC ALL FAD (a) YFT Mean weight (kg) FSC ALL FAD (b) SKJ Mean weight (kg) Mean weight (kg) FSC ALL FAD (c) BET Figure 16: Annual time series of mean weight (kg) for (a) yellowfin, (b) skipjack, and (c) bigeye tuna for each fishing mode during 1982-

17 2. Tables Table 1: Annual number of vessels by flag for the European tropical tuna purse seine fishing fleet of the Indian Ocean during FRA = France, FRAT = France Overseas Territories, ESP = Spain, CIV = Ivory Coast, PAN = Panama, SYC = Seychelles, MLT = Malte, VCT = Saint Vincent, IRN = Iran, ITA = Italy, BEL = Belize Year FRA FRAT ESP CIV PAN SYC MLT VCT IRN ITA BEL TOTAL

18 Table 2: Annual number of purse seiners by size category and total carrying capacity of the European tropical tuna purse seine fishing fleet of the Indian Ocean during Total carrying capacity (CC) was weighted by the proportion of the year at sea (in months) Year >2000 Nb vessels Nb vessels weighted CC

19 Table 3: Annual nominal fishing effort of the European Union and associated flags purse seine fishing fleet expressed in fishing and searching days during Searching days was derived from the total time spent at sea corrected for periods of damage, route towards port, and purse seine operation Year Fishing days Searching days

20 Table 4: Annual number of 1-degree squares explored by the European Union and associated flags purse seine fishing fleet during #sets indicates squares where a least 1 fishing set was made. Year TOTAL #sets Catch >0 Effort > 1 d Effort > 5 d

21 Table 5: Number of positive and null sets by fishing mode made by the European Union and associated flags purse seine fishing fleet in the Indian ocean during FAD = Fish Aggregating Device; FSC = Free-Swimming School ALL FAD FSC Total Positive Null Total Positive Null Total Positive Null

22 Table 6: Catch by species for the European Union and associated flags purse seine fishing fleet of the Indian ocean during Year YFT SKJ BET ALB OTH TOTAL

23 Table 7: Catch by species made on FAD-associated schools for the European Union and associated flags purse seine fishing fleet of the Indian ocean during Year YFT SKJ BET ALB OTH TOTAL

24 Table 8: Catch by species made on free-swimming schools for the European Union and associated flags purse seine fishing fleet of the Indian ocean during Year YFT SKJ BET ALB OTH TOTAL

25 Table 9: Number of sets per searching on FAD-associated (FAD) and free-swimming schools (FSC) for the European Union and associated flags purse seine fishing fleet of the Indian ocean during Year FAD FSC

26 Table 10: Catch per unit of effort (in t per positive set) on FAD-associated schools for the European Union and associated flags purse seine fishing fleet of the Indian ocean during Year YFT SKJ BET ALB TOTAL

27 Table 11: Catch per unit of effort (in t per positive set) on free-swimming schools for the European Union and associated flags purse seine fishing fleet of the Indian ocean during Year YFT SKJ BET ALB TOTAL

28 Table 12: Catch per unit of effort (in t per searching day) on FAD-associated schools for the European Union and associated flags purse seine fishing fleet of the Indian ocean during Year YFT SKJ BET ALB TOTAL

29 Table 13: Catch per unit of effort (in t per searching day) on free swimming schools for the European Union and associated flags purse seine fishing fleet of the Indian ocean during Year YFT SKJ BET ALB TOTAL