Shark Depredation and Unwanted Bycatch in Pelagic Longline

More documents

Recommendations

Info

Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries A4.6. Interview Results None of the interviewed fishermen are concerned with shark damage to their gear. They estimate the damage caused by the sharks in a typical set is close to zero. They reported that, at the moment, a high amount of shark interactions simply does not occur. When it occurs, the part of the gear that is most often lost to sharks is the end of the branch line with hook and bait. A few branch lines (0 to 10) are lost on a typical set owing to sharks, so fishermen spend a very little time and money replacing gear. Usually none, sometimes only one or two target fishes per set are damaged or lost to sharks. Fishermen say they can recognize shark damage versus other fish, cetacean, or squid damage according to bite characteristics. Almost every time they find a cut branch line, they say that is a consequence of a shark catch. Shark species interacting with longline fishing gear are mostly blue shark (Prionace glauca, 0-2 catches per fishing trip), while porbeagle (Lamna nasus), shortfin mako (Isurus oxyrichus) and smooth-hounds (Mustelus sp.) are rare. In their opinion the first most frequently by-caught shark species is the blue shark (Prionace glauca), the second is the thresher shark (Alopias vulpinus), the third is the porbeagle (Lamna nasus). Other occasionally caught species are the shortfin mako (Isurus oxyrichus), the hammerheads (Sphyrna sp.) and the smooth-hounds (Mustelus sp.). Most specimens are alive when hauled to the boat. All mentioned species are marketable, but meat is sold at a low price (2-5 €/kg). The thresher shark and the porbeagle are easily sold, the blue shark has a low value (and almost all fishermen discard it), the hammerheads in some cases are discarded because of the strong smell. Fishermen discard not marketable sharks, usually by cutting the branch line. The dehooker is largely unknown but, even when this gear is shown, they say it is more simple and safer to cut the branchline. When a shark is marketable, instead, it is hauled, killed by beating and eviscerated. Entrails are discarded and thrown into the water. Finning has never occurred, and the meat is the only part of shark to be sold. Even the long tail of the thresher shark (Alopias vulpinus), that is usually cut for convenience, is discarded. All interviewed fishermen do not know about shark regulations (e.g. Council Regulation (EC) 1185/2003 forbidding finning) and about protected shark species (e.g. basking shark Cetorhinus maximus, CITES Appendix II). Anyway, catching sharks is not a profitable business for fishermen at the moment (as well as in the past). When asked, they say they would like to avoid shark capture without lowering the catch of target species. On the other hand, Italian fishermen are very quick in catching opportunities. If there were substantial shark populations in the Italian waters and a local market for shark fins, probably they would fish for sharks. By now, the revenue from sharks is so low that it does not exceed the cost of catching them. In fishermen’s opinion, no regulation changes could affect this trend. All interviewed fishermen do not use shark catch and depredation avoidance methods, and did not try such methods in the past. When they have a higher shark by-catch rate, they do not change the way they fish (e.g. changing position, time, or bait). Some of them (4) said that 30 years ago they used branch line with a more strong end part (near the hook), in order to reduce the cutting by the shark and capture it. This type of fishing was never done for selling the meat or other parts of a shark, but only to avoid loosing the branch line. Fishermen said that they would kill every shark caught to reduce shark abundance, which they believed would increase the swordfish catch rate. Regarding opinions on the possible efficacy of avoidance methods, some fishermen think it is possible to avoid peak areas and times of shark abundance, and some think it is possible to reduce the detection of baited hooks by refraining from chumming during the set and not discarding offal and spent bait during the haul. In any case, they have never tried these methods, and no one has ever chummed while fishing. Some fishermen point out that the attractiveness of baited hooks to sharks can be reduced using mackerel instead of squid bait. In fishermen’s opinion, the most important factor that affects shark catch is the hooks depth, followed by topographic and oceanographic features. Interviewed fishermen are not inclined to use dehookers to release sharks, some actually usually do not haul sharks (even marketable ones) to avoid the risk of handling. Captains and crew are little interested in reducing shark capture and depredation. They have a very pragmatic attitude towards sharks, with no consciousness of their ecological role. They know sharks are not economically profitable, and they are persuaded that sharks are now rare in the Italian waters (many fishermen compare actual very low shark by-catch rates with very high rates dating back to more than a decade ago). On the other hand, sharks cause little damage to fishing gear and are dangerous to handle, so fishermen would like to avoid them, if avoidance methods do not lower the catch rate of target species. A4.7. Shark Trade As Vannuccini (1999) reported to FAO, Italian shark export has ever been of little importance; for example in 2004 recorded values were 199 t and 469,000 $ (FAO, 2006). No data on the fishing gear used to catch these sharks is available. On the other hand Italy is one of the leading world importers of sharks (Table A4.21). In 1998 the major supplier to Italy was Spain, followed by Netherlands, United Kingdom, South Africa and France (Vannuccini, 1999). Porbeagle (Lamna nasus), smooth-hounds (Mustelus spp.), catsharks (Scyliorhinus spp.) and piked dogfish (Squalus acanthias) are shown in the list of the most imported species (Vannuccini, 1999). 82
Italy Mediterranean Industrial Pelagic Longline Swordfish Fishery Table A4.21. Import of shark products in Italy: quantity and values (FAO Fishstat Plus - Commodities production and trade 1976-2004). 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Sharks, fresh or chilled Sharks, frozen Shark fillets, frozen Quantity (t) 530 453 424 580 614 700 837 709 751 850 Value (000 $) 2,841 2,785 2,449 3,116 3,173 3,006 3,628 3,463 4,114 5,070 Quantity (t) 9,584 11,913 11,409 11,475 10,654 10,031 9,736 7,942 6,379 7,213 Value (000 $) 26,562 27,687 26,243 23,429 20,719 19,973 19,646 12,381 10,316 14,015 Quantity (t) 395 264 266 447 413 373 485 759 603 755 Value (000 $) 1,445 1,019 857 A4.8. References Commission of the European Communities, 2003. Report of Ad Working Group - Elasmobranchs Fisheries. Commission Staff Working Paper SEC(2003)1427. Commission Regulation (EC) No 2091/1998 of 30 September 1998. Segmentation of the Community fishing fleet and fishing effort in relation to the multi-annual guidance programmes (MAPG) - Annex I. Commission Regulation (EC) No 26/2004 of 30 December 2003. On the Community fishing fleet register. Council Regulation (EC) No 1626/1994 of 27 June 1994. Laying down certain technical measures for the conservation of fishery resources in the Mediterranean. Council Regulation (EC) No 1185/2003 of 26 June 2003. On the removal of fins of sharks on board vessels. De Metrio G., Cacucci M., Deflorio M., Desantis S., Santamaria N., 2000. Incidence of the large pelagic fishing on the shark catches. Biol. Mar. Medit., 7 (1): 334-345. De Metrio G., Petrosino G., Montanaro C., Matarrese A., Lenti M., Cecere E., 1984. Survey on summer-autumn population of Prionace glauca L. (Pisces, Chondrichthyes) in the Gulf of Taranto (Italy) during the four year period 1978-1981 and its incidence on sword-fish (Xiphias gladius L.) and albacore (Thunnus alalunga (Bonn.)) fishing. Oebalia, Vol. X, N.S.: 105-116. De Metrio G., Petrosino G., Tursi A., Chieppa M., 1982a. Andamento della pesca di Prionace glauca L. nel biennio 1979-1980 al largo delle coste ioniche del Salento (Pisces, Chondrichthyes). Naturalista sicil., S. IV, VI (Suppl.), 2: 413-419. De Metrio G., Petrosino G., Tursi A., Francioso E., 1982b. Comparazione chimica, aminoacidica ed elettroforetica delle carni di Mustelus mustelus L. e di Prionace glauca L. (Nota preliminare). Atti Società Italiana delle Scienze Veterinarie, 35: 646-647. De Zio V., Pastorelli A.M., Rositani L., 2000. By catch of blue shark Prionace glauca (L.) during large pelagic fishery in southern Adriatic Sea (1984- 1998). Biol. Mar. Medit., 7 (1): 444-446. Di Natale A., 1998. By-catch of shark species in surface gear used by the Italian fleet for large pelagic species. Col. Vol. Sci. Pap. ICCAT, 48 (3): 138-140. FAO Fishstat Plus: Universal software for fishery statistical time series. Version 2.31. Datasets: GFCM Capture Production 1970-2004; Commodities production and trade 1976-2004. Food and Agriculture Organization of the United Nations, Fisheries Department, Fishery Information, Data and Statistics Unit. (www.fao.org/fi/statist/FISOFT/ FISHPLUS.asp). Ferretti M., Tarulli E., Palladino S. (Eds.), 2002. Classificazione e descrizione degli attrezzi da pesca in uso nelle marinerie italiane con particolare riferimento al loro impatto ambientale. Quaderno ICRAM n° 3, Roma, 126 pp. Filanti T., Megalofonou P., Petrosino G., De Metrio G., 1986. Incidenza dei Selaci nella pesca del pesce spada con long-line nel Golfo di Taranto. Nova Thalassia, 8, Suppl. 3: 667-669. Garibaldi F., Orsi Relini L., 2000. Summer abundance, size and feeding habits of the blue shark, Prionace glauca, in the pelagic sanctuary of the Ligurian Sea. Biol. Mar. Medit., 7 (1): 324-333. Guglielmi P., Di Natale A., Pelusi P., 2000. Effetti della pesca con il palangaro derivante sui grandi pelagici e sulle specie accessorie nel Mediterraneo centrale. Rapporto al Ministero per le Politiche Agricole e Forestali, DGPA, Roma. Unpublished report. IREPA, 2006. Osservatorio economico sulle strutture produttive della pesca marittima in Italia 2004. Franco Angeli, Milano, 294 pp. ISTAT, 2004. Dati annuali sulla pesca. ISTAT Servizio Agricoltura, Allevamenti e Pesca, Roma. ISTAT, 2006. Principali risultati sull’attività di pesca anno 2004. ISTAT Servizio Agricoltura, Allevamenti e Pesca, Roma. IUCN Shark Specialist Group Red List assessments, 2000-2006 (last updated May 2006). Marano G., Rositani L., Ungaro N., De Zio V., 1988. Cours des prises avec palangre de surface dan l’Adriatique du sud (cotes italiennes), triennat 1984-86. Fao Fish. Rep. 394: 112-120. Megalofonou P., Yannopoulos C., Damalas D., De Metrio G., Deflorio M., de la Serna J.M., Macias D., 2005. Incidental catch and estimated discards of pelagic sharks from the swordfish and tuna fisheries in the Mediterranean Sea. Fish. Bull., 103 (4): 620-634. Megalofonou P., Damalas D., Yannopoulos C., De Metrio G., Deflorio M., de la Serna J.M., Macias D., 2000. By-catches and discards of sharks in the large pelagic fisheries in the Mediterranean Sea. European Union Project 97/50 Directorate General XIV/C1, 336 pp. Ministerial Decree 26 July 1995. Disciplina del rilascio delle licenze di pesca. Ministero delle Risorse Agricole, Alimentari e Forestali, Roma. Ministerial Decree 14 September 1999. Disciplina della piccola pesca. Ministero delle Risorse Agricole, Alimentari e Forestali, Roma. Orsi Relini L., 2000. Longline fisheries, blue shark catches and conservation problems. Biol. Mar. Medit., 7 (1): 313-323. Orsi Relini L., Palandri G., Garibaldi F., Cima C., 1999. Longline swordfish fishery in the Ligurian Sea: eight years of observations on target and bycatch species. Col. Vol. Sci. Pap. ICCAT, 49 (1): 146-150. UNIMAR, 2001. Gli attrezzi da pesca in uso nelle Marinerie Italiane - Primi risultati del programma MAPP. Consorzio Unimar, Roma, 16 pp. Vacchi M., Notarbartolo di Sciara G., 2000. The cartilagineous fishes in Italian Seas, a resource that urges to be protected. Biol. Mar. Medit., 7 (1): 296-311. Vannuccini, S., 1999. Shark Utilization, Marketing and Trade. FAO Fisheries Technical Paper, Rome. 83
Page 3 and 4:
Shark Depredation and Unwanted Byca
Page 5:
Page 9 and 10:
Contents Summary and Conclusions 1
Page 11 and 12:
Contents Appendix 3. Fiji Pelagic L
Page 13:
Contents Appendix 8. USA Hawaii Lon
Page 16 and 17:
Page 19 and 20:
Chapter 1 Introduction and Methods
Page 21 and 22:
Introduction and Methods 1.2. Metho
Page 23 and 24:
Fishing Gear and Operational Charac
Page 25 and 26:
Fishing Gear and Operational Charac
Page 27 and 28:
Shark Catch Rates and Disposition T
Page 29 and 30:
Chapter 4 National and Internationa
Page 31 and 32:
National and International Measures
Page 33 and 34:
Economic, Practical, Ecological and
Page 35 and 36:
Economic, Practical, Ecological and
Page 37 and 38:
Chapter 6 Industry Attitudes and Pr
Page 39 and 40:
Industry Attitudes and Practices Lo
Page 41 and 42:
Industry Attitudes and Practices Fi
Page 43 and 44:
Chapter 7 Potential of Deterrents,
Page 45 and 46: Potential of Deterrents, Hotspot Av
Page 47 and 48: References Campana, S.E., L. Marks,
Page 49: References Neves dos Santos, M., Ga
Page 52 and 53: Shark Depredation and Unwanted Byca
Page 99 and 100: Appendix 5 Japan Pelagic Longline F
Page 101 and 102: Japan Pelagic Longline Fisheries Fi
Page 103 and 104: Japan Pelagic Longline Fisheries mo
Page 105 and 106: Japan Pelagic Longline Fisheries Ta
Page 107 and 108: Japan Pelagic Longline Fisheries is
Page 109 and 110: Japan Pelagic Longline Fisheries ta
Page 111 and 112: Japan Pelagic Longline Fisheries In
Page 113 and 114: Japan Pelagic Longline Fisheries A5
Page 115 and 116: Appendix 6 Peru Artisanal Mahimahi
Page 117 and 118: Peru Artisanal Mahimahi And Shark L
Page 127 and 128: Appendix 7 South Africa Pelagic Lon
Page 129 and 130: South Africa Pelagic Longline Tuna
Page 135 and 136: Appendix 8 USA Hawaii-based Pelagic
Page 137 and 138: USA Hawaii-based Pelagic Longline S
Page 147 and 148:
Appendix 9 USA Atlantic, Gulf of Me
Page 149 and 150:
USA Atlantic, Gulf of Mexico and Ca
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
show all

Shark Depredation and Unwanted Bycatch in Pelagic Longline

Create successful ePaper yourself

Delete template?

Save as template?