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Volumn 299, Issue 5605, 2003, Pages 389-392

Collapse and conservation of shark populations in the Northwest Atlantic

Author keywords

[No Author keywords available]

Indexed keywords

BIODIVERSITY; DATA REDUCTION; POPULATION STATISTICS;

EID: 0037449550     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.1079777     Document Type: Article
Times cited : (949)

References (37)
  • 1
    • 0035827303 scopus 로고    scopus 로고
    • J. Alroy, Science 292, 1893 (2001).
    • (2001) Science , vol.292 , pp. 1893
    • Alroy, J.1
  • 5
    • 0347755518 scopus 로고    scopus 로고
    • note
    • The low fecundity and late age at maturity of elasmobranchs (sharks, skates, rays) render these fishes more vulnerable to overexploitation than most teleost fishes, as evidenced by the history of collapsed shark fisheries (6).
  • 10
    • 0347755517 scopus 로고    scopus 로고
    • note
    • We examined all available scientific observer and logbook data for the pelagic longline fleets targeting swordfish and tunas in the Northwest Atlantic: (i) U.S. observers on Japanese boats (1978 to 1988); (ii) U.S. observers on U.S. boats (198S to 2000); (iii) Canadian observers on Japanese boats (1979 to 1984, 1986 to 2000); (iv) Canadian observers on Canadian boats (1979 to 2000); and (v) logbook data from U.S. boats (1986 to 2000). For each of these data sets, we standardized catch per unit effort (CPUE) time series using CLMs to obtain unbiased indices of abundance. Reliable trends could only be estimated from (v). Estimated trends from (i) to (iv) were extremely uncertain and contained much wider year-to-year fluctuations than are realistic according to shark life histories. This is likely the result of limited and/or nonrandom fleet coverage (<5%), or the limited temporal and spatial overlap among data sets.
  • 11
    • 0346494799 scopus 로고    scopus 로고
    • note
    • If the reporting rate has changed over time, then the ratio of missing values to true zeros will change, and using the assumed zeros to infer trends may lead to biased results.
  • 13
    • 0346494800 scopus 로고    scopus 로고
    • note
    • Methods and robustness analysis details are available as supporting online material on Science Online.
  • 17
    • 0345863887 scopus 로고    scopus 로고
    • note
    • No white sharks have been caught in the 4200 sets monitored since 1990 by the U.S. observer programs for pelagic longline fleets in this region. Before this time, observers had recorded 142 white sharks.
  • 21
    • 0347125184 scopus 로고    scopus 로고
    • note
    • Controversy over 1997 large coastal shark quota cuts resulted in lawsuits between the fishing industry and the U.S. National Marine Fisheries Service (NMFS). In 2002, a lawsuit protesting NMFS's failure to protect these species was also launched.
  • 23
  • 26
    • 0035902978 scopus 로고    scopus 로고
    • B. A. Block et al., Science 293, 1310 (2001).
    • (2001) Science , vol.293 , pp. 1310
    • Block, B.A.1
  • 28
    • 0347125185 scopus 로고    scopus 로고
    • U.S. Federal Register, vol. 66, p. 36711. This closure remains enforced to date (U.S. Federal Register, vol. 67, p. 45393).
    • U.S. Federal Register , vol.66 , pp. 36711
  • 29
    • 0347125187 scopus 로고    scopus 로고
    • U.S. Federal Register, vol. 66, p. 36711. This closure remains enforced to date (U.S. Federal Register, vol. 67, p. 45393).
    • U.S. Federal Register , vol.67 , pp. 45393
  • 30
    • 0347125188 scopus 로고    scopus 로고
    • note
    • We included sea turtle and finfish species listed by the International Union for the Conservation of Nature (IUCN) and/or NMFS as severely overfished, with further overfishing occurring, threatened, or endangered (see table S2 for details). Common dolphinfish, wahoo, and oilfish were included because they are caught in large numbers, but very little is known about their stock status and sensitivity to overfishing. All species were caught in at least two areas with a minimum sample size of 25 individuals.
  • 31
    • 0003522666 scopus 로고    scopus 로고
    • IUCN, Gland, Switzerland, and Cambridge, UK
    • IUCN, 2002 IUCN Red List of Threatened Species (IUCN, Gland, Switzerland, and Cambridge, UK, 2002) (www.redlist.org).
    • (2002) 2002 IUCN Red List of Threatened Species
  • 35
    • 0347755514 scopus 로고    scopus 로고
    • note
    • NMFS has reduced directed shark fishery quotas and has also closed areas within the Gulf of Mexico and along the U.S. east coast in 2000 and 2001, respectively, with the aim of reducing incidental catch (of species other than sharks) (31). No analysis has been undertaken to test their effectiveness.
  • 36
    • 0004201345 scopus 로고    scopus 로고
    • National Marine Fisheries Service, Highly Migratory Species Management Division, Silver Spring, MD
    • NMFS Final Fishery Management Plan for Atlantic Tuna, Swordfish, and Sharks (National Marine Fisheries Service, Highly Migratory Species Management Division, Silver Spring, MD, 1999).
    • (1999) Final Fishery Management Plan for Atlantic Tuna, Swordfish, and Sharks
  • 37
    • 0347755515 scopus 로고    scopus 로고
    • note
    • We thank NOAA-NMFS for data; J. Cramer, L. R. Beerkircher, and J. Musick for advice; W. Blanchard, L. Gerber, and M. Ortiz for technical assistance; H. Keith for initial dosed-area model implementation; and H. K. Lotze and H. Whitehead for comments on the manuscript. Many thanks to the longline fishers who provided their logbooks to NMFS. This research is part of a larger project on pelagic longlining initiated and supported by a Pew Charitable Trusts grant to L.B. Crowder and R.A.M., with additional support by Natural Sciences and Engineering Research Council of Canada scholarships to J.K.B. and D.G.K.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.