Polyprion americanus (Brazilian subpopulation)
|Scientific Name:||Polyprion americanus (Brazilian subpopulation)|
|Species Authority:||(Bloch & Schneider, 1801)|
|Taxonomic Notes:||The wreckfishes (Polyprionidae) are a small family with only 4 recognized species. However, Roberts (1986) synonymized all existing names into just two: P. americanus and P. oxygeneios. Others (Ball et al. 2000) have used genetics and found that all 4 species may be valid. There is a need to resolve this confusion even though it has not been suggested that P. americanus is not a valid species|
|Red List Category & Criteria:||Critically Endangered A2abd ver 3.1|
|Assessor(s):||Cornish, A.S. & Peres, M.B.|
|Reviewer(s):||Sedberry, G. & Sadovy, Y. (Grouper & Wrasse Red List Authority)|
The Brazilian subpopulation of Polyprion americanus is assessed as Critically Endangered (CR A2abd).
Catch per unit effort (CPUE), which can be used to estimate relative abundance, declined by 90% (0.72 to 0.073 kg/day/hook) off southern Brazil from 1989/91 to 1997/98 (Peres 2000). There was also a decrease in nominal wreckfish catch per day at sea from 706 kg/day (1995–6) to 250 kg/day (1997–8), a decline of 64.5 % (Peres 2000). The corresponding decline in abundance of wreckfish is likely to be greater than this as there were also technological improvements in fishing gear over the same period (Peres and Haimovici 1998).
In addition, the only estimated annual landings data show a decline: 2,772 mt (1989), 2,150 mt (1990), 1,674 mt (1991), 2,291 mt (1994), 1080 mt (1995) (Peres 2000) and 1,350 mt (1998) (Haimovici and Velasco 1998). It is known that the number of vessels in the fishery increased from 10 in the 1970s to more than 35 in 1997 and that, therefore, catch has declined despite increasing fishing effort, but without more data on the resulting changes to actual fishing effort (there have also been technological advances in the gears used), the landings data are difficult to interpret in more detail. The best proxy for abundance will be CPUE, although even this is likely to be an underestimate due to the fact that the "J" hooks were changed to more effective circular ones over the same period (Peres and Haimovici 1998). The CPUE decline of 90% from 1989/91 to 1997/98 is used to infer a population size reduction of > 80% over the 30 years prior to 2003 in Brazil (since 1993, the fishery for wreckfish has covered all the known distribution of wreckfish in Brazil; Peres and Haimovici 1998). The CPUE figures do include late juveniles (Peres 2000) but this is not believed to be a problem (population size by IUCN definition is only of mature individuals) as in 2000 fishers reported that mature individuals were getting proportionally rarer (Peres pers. comm.) indicating the population reduction may be > 90% if only mature fish are included. Early juveniles are pelagic up to 50–60 cm length (Sedberry et al. 1999) It is recognized that there is a need for more recent CPUE data in order for this assessment to be up-to-date in case there has been a change in circumstances but given that i) last reports in 2000 were that the fishery was still expanding (Peres pers. comm.) and, ii) the generation time is long (estimated at 7–22 years in the global red list assessment for this species), it is very unlikely wreckfish population size has increased since 1998.
|Range Description:||Globally, the species has a large but discontinuous range in the Atlantic, Pacific and Indian Oceans, also the Mediterranean. In the Eastern Atlantic it ranges from Norway to South Africa including the Mediterranean, Canary Islands, Madeira, Cape Verde, and Tristan da Cunha. In the Western Atlantic it is found in Newfoundland, Canada and Gulf of Maine to North Carolina, USA. In the Southern hemisphere it is known from Uruguay, Brazil, Argentina and New Zealand, also St. Paul and Amsterdam islands in the Western Indian Ocean (see FishBase 2003).
The current assessment is restrictd to the Brazilian subpopulation only. Extent of occurrence and area of occupancy are not known due to this fish living in deep waters.
|FAO Marine Fishing Areas:|
Atlantic – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There is no information on population size, but the fisheries data indicates these fish are not very abundant.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Wreckfish are found mainly on irregular substrate, late juveniles are found from 60-250 m depth while adults are deeper at 150-250 m (Peres 2000). Wreckfish inhabit demersal habitats where temperature ranges from 6.0 to 16.3 ºC (Sedberry et al. 1999).
The fishery in Brazil targets spawning aggregations in the area north of Rio Grande (28 to 30ºS), in austral winter and spring (Peres 2000).
|Major Threat(s):||The only known threat is from overfishing. The fishery in Brazil targets spawning aggregations thus increasing the vulnerability of this animal to overfishing (Peres 2000). Local fishers in 2000 stated that mature fish had become rare in the previous year or so (Peres pers. comm.).|
|Conservation Actions:||None currently in place.|
Ball, A.O., Sedberry, G.R., Zatcoff, M.S., Chapman, R.W. and Carlin, J.L. 2000. Population structure of the wreckfish Polyprion americanus determined with microsatellite genetic markers. Marine Biology 137: 1077-1090.
Haimovici, M. and Velasco, G. 1998. A pesca de espinhel de fundo na região sul do Brasil em 1997 e 1998. Documentos Técnicos, Oceanografia. 11.
IUCN. 2003. 2003 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 18 November 2003.
Peres, M.B. 2000. Dinâmica populacional e pesca do cherne-poveiro Polyprion americanus (Bloch & Schneider, 1801) (Teleostei: Polyprionidae) no sul do Brasil. PhD Thesis. Fundação Universidade do Rio Grande (FURG).
Peres M.B. and Haimovici, M. 1998. A pesca diridida ao do cherne-poveiro Polyprion americanus (Polyprionidae: Teleostei) no sul do Brasil. Atlântica 20: 141-161
Roberts, C.D. 1986. Systematics of the percomorph fish genus Polyprion Oken, 1817. Ph.D. Diss., Univ. Wellington. 283 pp
Sedberry G.R., Andrade C.A.P., Carlin J.L., Chapman R.W., Luckhurst B.E., Manooch C.S. III, Menezes G., Thomsen B. and Ulrich G.F. 1999. Wreckfish Polyprion americanus in the North Atlantic: Fisheries, Biology, and Management of a widely distributed and Long lived fish. American Fisheries Society Symposium 23:27-50
|Citation:||Cornish, A.S. & Peres, M.B. 2003. Polyprion americanus (Brazilian subpopulation). The IUCN Red List of Threatened Species 2003: e.T43973A10846163.Downloaded on 23 July 2016.|