Sarda chiliensis, Pacific Bonito

Transcription

1 The IUCN Red List of Threatened Species ISSN (online) IUCN 2008: T170352A Sarda chiliensis, Pacific Bonito Assessment by: Collette, B. et al. View on Short citation: Collette, B. et al Sarda chiliensis. The IUCN Red List of Threatened Species 2011: e.t170352a [see full citation at end] Copyright: 2015 International Union for Conservation of Nature and Natural Resources Reproduction of this publication for educational or other non-commercial purposes is authorized without prior written permission from the copyright holder provided the source is fully acknowledged. Reproduction of this publication for resale, reposting or other commercial purposes is prohibited without prior written permission from the copyright holder. For further details see Terms of Use. The IUCN Red List of Threatened Species is produced and managed by the IUCN Global Species Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership. The IUCN Red List Partners are: BirdLife International; Botanic Gardens Conservation International; Conservation International; Microsoft; NatureServe; Royal Botanic Gardens, Kew; Sapienza University of Rome; Texas A&M University; Wildscreen; and Zoological Society of London. If you see any errors or have any questions or suggestions on what is shown in this document, please provide us with feedback so that we can correct or extend the information provided. THE IUCN RED LIST OF THREATENED SPECIES

2 Taxonomy Kingdom Phylum Class Order Family Animalia Chordata Actinopterygii Perciformes Scombridae Taxon Name: Sarda chiliensis (Cuvier, 1832) Synonym(s): Pelamys chiliensis Common Name(s): English: Taxonomic Notes: Pacific Bonito Two subspecies are recognized: Sarda chiliensis lineolata occurs from Alaska to the tip of Baja California and the southwest Gulf of California, and the Revillagigedo Islands. Sarda chiliensis chiliensis occurs from Ecuador to Chile (Collette and Chao 1975). Assessment Information Red List Category & Criteria: Least Concern ver 3.1 Year Published: 2011 Date Assessed: May 24, 2007 Justification: This species is endemic to the Eastern Pacific. Catch statistics have dramatically fluctuated but there is no clear indication of population decline. This species is listed as Least Concern. However, given this species dramatic fluctuations in catch landings, it should be carefully monitored. For further information about this species, see Supplementary Material. Geographic Range Range Description: Pacific Bonito are endemic to the Eastern Pacific and are divided into two geographically distinct populations. The California fishery targets the northern subspecies, Sarda chiliensis lineolata, which ranges from the Gulf of Alaska to the Revillagigedo Islands, Mexico. This population is centred between southern California and central Baja California, Mexico and moves farther north in warm water years. The southern subspecies, Sarda chiliensis chiliensis, is found off the western coast of South America from Colombia to Chile. Sarda orientalis is present in the gap between the two subspecies of S. chiliensis (Collette and Chao 1975). Country Occurrence: Native: Chile; Colombia; Ecuador; Mexico; United States 1

3 FAO Marine Fishing Areas: Native: Pacific - eastern central, Pacific - northeast, Pacific - southeast 2

4 Distribution Map 3

5 Population The northern subspecies, Sarda chiliensis lineolata, is a component of the commercial purse seine fishery as well as a popular recreational fish in southern California. Catch landings for this subspecies have greatly fluctuated, and therefore it is difficult to estimate the effect of fishing on its population. It is not clear what is causing these fluctuations. Pacific Bonito populations fluctuate on a decadal scale in a similar manner as the northern anchovy. Current conditions indicate that the eastern Pacific is in a warm water regime that favours Pacific Sardine over Northern Anchovy, which is a primary prey species for Pacific Bonito. It is therefore thought that these fluctuations in both anchovy and Pacific Bonito are associated with warm and cold water periods of the Pacific Decadal Oscillation (California Department of Fish and Game 2010). Commercial landings for this subspecies have declined steadily since the mid 1980s, but have increased moderately in recent years, from 291 metric tons in 1997 to 803 metric tons in The trend over the last 15 years seems to be low landings for most years interspersed with high yield years. Competition with higher valued fisheries was likely part of the decline observed in landings during the 1980s and 1990s. Additionally, increased regulation, decreased stocks and lower market demand likely contributed to the decline. In 1982, Mexico began restricting foreign vessel access to its near-shore fisheries. Prior to this closure, 50 90% of Pacific Bonito landed in the United States was caught off the coast of Baja California, Mexico. Now less than 10% originates in Mexican waters (California Department of Fish and Game 2010). FAO reported landings for Sarda chiliensis (both subspecies) highly fluctuate and range from 35,016 tonnes reported in 1950 to 11,3161 tonnes in 1961; to 2,383 tonnes reported in 2003 and 6,243 tonnes reported in 2006 (FAO 2009). Landings in California and Mexico have fluctuated greatly over the past 50 years from less than 1,000 metric tons to nearly 14,000 mt in the early 1970s (worth $1,222,000 in total California landings in 1976) (Collette and Nauen 1983). Combined landings of U.S. and Mexico in 1995 was about 6,800 mt, while in the last five years ( ), the landings have been under 500 mt (FAO 2009), representing a decline of over 90%, assuming landings are a good proxy for population trends. The combined Chilean and Peruvian landings of the southern subspecies, Sarda chiliensis chiliensis, went from almost zero in 1,940 mt to a peak of around 110,000 mt in 1961 and dropped off to about 40,000 mt in 1973 (Collette and Nauen, 1983). From the catch reduction went from around 30,000 mt per year to around 1,000 to 5,000 mt per year (FAO 2009). Reported landings for this species (in Ecuador, Chile and Peru) plunged to between 1,000 and 5,000 mt per year between 1998 and A conservative estimate is a reduction in catch of around 80% since In Peru, however, there was a decrease in effort during the late 1990s which may reflect the decrease in catch at this time. Also drops in catch may be related to reduction in anchovies, but also during this time there was an increase in effort for Jack Mackerel and Scomber japonicus. Although the catch is rising again in 2005 and 2006, this is likely due to an increase in fishing effort. In Chile, less than 10,000 mt in the 1960 and 1970s was estimated to be caught, and this was the period of the highest catches (R. Sierra pers. comm. 2008). FAO data for catches from Chile are not necessarily correct for this species, especially in the 1980s. 4

6 In the Eastern Pacific, landings data are combined for two bonito species, S. orientalis and both subspecies of S. chiliensis (IATTC 2008). The maximum catch was 14,000 metric tonnes in 1977 and After 1999 the total catch dropped from thousands metric tonnes to under 1,000 metric tonnes per year with a minimum of 43 in 2003, but may be increasing again as 3,600 tonnes was reported in 2006 (IATTC 2008). It is most likely that the majority of these landings data are for S. chiliensis chiliensis, as the majority of the catch was from Chile and Peru. Current Population Trend: Decreasing Habitat and Ecology (see Appendix for additional information) This pelagic and oceanodromous species is found inshore and forms schools by size. It feeds on a variety of small schooling fishes, squids, and shrimps (Collette and Nauen, 1983). Males can mature and spawn at one year of age at a length of approximately 51 cm. Females usually spawn more than once per season beginning at two years of age. However, most are approximately 69 cm long or three years old at first spawning (California Department of Fish and Game 2010). It is not likely to live longer than six years. Generation time is estimated to be around 3 4 years. Maximum Size is 102 cm fork length (FL). The all-tackle game fish record is of a 9.67 kg fish caught at 181 Spot off California (IGFA 2011). Systems: Marine Use and Trade (see Appendix for additional information) Pacific Bonito are caught incidentally in commercial fisheries and are a popular recreational species. They are considered an excellent food fish.. Threats (see Appendix for additional information) This species is important in minor commercial fisheries. It is harvested in the USA and Mexico, primarily using purse seines, and is also important in sport fisheries in California. Targeting of this species off California occurs primarily off San Pedro with smaller purse seine boats, with consistent effort. Total catch of all three populations of bonitos (including S. orientalis) in the eastern tropical Pacific was reported by Inter-American Tropical Tuna Commission (IATTC) as 10,000 metric tons, dropping to 300 2,600 mt in , and then increasing to 17,000 mt in 2007 (IATTC 2008). Conservation Actions Pacific Bonito is included in the federal Highly Migratory Species Fishery Management Plan as a "monitored species", meaning it is not actively managed. Currently, only California statues and regulations apply to the take of this species. If there is an increase in take of Pacific Bonito, its status could be changed to actively managed. It is legal to target Pacific bonito commercially and recreationally year round (California Department of Fish and Game 2010). After the last population assessment in 1982, a minimum size limit of 24 inches (61 cm) or five pounds (2.3 kg) was instituted for both commercial and recreational fisheries. In the recreational fishery there is a ten fish bag limit and up to five undersized fish can be retained. Commercial vessels fishing with round 5

7 haul gear (e.g., purse seine, lampara net) may retain 18 or less by number of undersized fish. When using gill or trammel nets, only 1,000 pound (454 kg) or less of undersized Pacific bonito may be retained (California Department of Fish and Game 2010). The minimum size for S. chiliensis lineolata in Peru is 52 cm FL with a maximum tolerance of juveniles od 10% of the catch. There are no catch quotas. Credits Assessor(s): Collette, B., Acero, A., Canales Ramirez, C., Cardenas, G., Carpenter, K.E., Di Natale, A., Guzman-Mora, A., Montano Cruz, R., Nelson, R., Schaefer, K., Serra, R. & Yanez, E. Reviewer(s): Russell, B. & Polidoro, B. 6

8 Bibliography California Dept. Fish and Game Status of the Fisheries Report: an update through In: California Dept. Fish and Game (eds). Collette, B.B Scombridae. Atunes, bacoretas, bonitos, caballas, estorninos, melva, etc. In: W. Fischer, F. Krupp, W. Schneider, C. Sommer, K.E. Carpenter, V.H. Niem (ed.), Guia para la identification de especies para los fines de la pesca, pp FAO, Rome. Collette, B. B. and Chao, L.N Systematics and morphology of the bonitos (Sarda) and their relatives (Scombridae, Sardini). Fishery Bulletin U.S. 73(3): Collette, B.B. and Nauen, C.E FAO Species Catalogue. Vol. 2. Scombrids of the World: an annotated and illustrated catalogue of tunas, mackerels, bonitos and related species known to date. Food and Agriculture Organization of the United Nations (FAO) Fisheries Synopsis number 125, volume 2. FAO FishStat Plus Version Universal Software for Fishery Statistics Time Series. Available at: IATTC The Fishery for Tunas and Billfishes in the Eastern Pacific Ocean in In: IATTC Document IATTC (ed.), IATTC 78th Meeting June Panama. IGFA World Record Game Fishes. International Game Fish Association, Dania Beach, Florida. IUCN IUCN Red List of Threatened Species (ver ). Available at: (Accessed: 10 November 2011). Samame, M Edad y Crecimiento del bonito Sarda Chiliensis Chiliensis. IMARPE 16(1): Viñas, J., Alvarado Bremer, J. R. and Pla, C Phylogeography and phylogeny of the epineritic cosmopolitan bonitos of the genus Sarda (Cuvier): inferred patterns of intra- and inter-oceanic connectivity derived from nuclear and mitochondrial DNA data. J. Biogeog. 37: Yoshida, H.O Synopsis of biological data on bonitos of the genus Sarda. NOAA Tech. Rep. NMFS Circ Citation Collette, B., Acero, A., Canales Ramirez, C., Cardenas, G., Carpenter, K.E., Di Natale, A., Guzman-Mora, A., Montano Cruz, R., Nelson, R., Schaefer, K., Serra, R. & Yanez, E Sarda chiliensis. The IUCN Red List of Threatened Species 2011: e.t170352a Disclaimer To make use of this information, please check the Terms of Use. External Resources For Supplementary Material, and for Images and External Links to Additional Information, please see the Red List website. 7

9 Appendix Habitats ( Habitat Season Suitability Major Importance? 9. Marine Neritic -> 9.1. Marine Neritic - Pelagic - Suitable Marine Oceanic -> Marine Oceanic - Epipelagic (0-200m) - Suitable - Use and Trade ( End Use Local National International Food - human No No No Threats ( Threat Timing Scope Severity Impact Score 5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> Motivation Unknown/Unrecorded Ongoing Stresses: 1. Ecosystem stresses -> 1.2. Ecosystem degradation Additional Data Fields Distribution Lower depth limit (m): 110 Upper depth limit (m): 0 Population Population severely fragmented: No Habitats and Ecology Generation Length (years): 3-4 8

10 The IUCN Red List Partnership The IUCN Red List of Threatened Species is produced and managed by the IUCN Global Species Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership. The IUCN Red List Partners are: BirdLife International; Botanic Gardens Conservation International; Conservation International; Microsoft; NatureServe; Royal Botanic Gardens, Kew; Sapienza University of Rome; Texas A&M University; Wildscreen; and Zoological Society of London. THE IUCN RED LIST OF THREATENED SPECIES