Atlantic blue marlin, Makaira nigricans, and white marlin, Tetrapterus albidus, bycatch of the Japanese pelagic longline fishery, 1960-2000

Joseph E. Serafy, Guillermo A. Diaz, Eric D. Prince, Eric S. Orbesen, Christopher M. Legault

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Since the late 1950's, a multi-national longline fishery has operated throughout the Atlantic Ocean to supply the growing global demand for tunas (Scombridae) and swordfish, Xiphias gladius. Two species caught as bycatch include Atlantic blue marlin, Makaira nigricans, and white marlin, Tetrapterus albidus, referred to in this paper as "Atlantic marlin." Pelagic longlining has consistently been the principal source of adult mortality for both species, which are currently depleted and have been so for more than two decades. In this paper, we examined aspects of the Atlantic marlin bycatch of the Japanese pelagic longline fishery from 1960 to 2000. Temporal and spatial patterns in effort, target catch (species combined), marlin bycatch, marlin catch-per-unit-effort (nominal CPUE), and ratios of marlin bycatch to target catch (B: T ratios) were analyzed. An objective was to reveal changes, if any, in marlin bycatch associated with the fishery's target species "switch" (ca. 1980-87) from mostly surface-associated tunas to mostly the deeper-dwelling bigeye tuna, Thunnus obesus. The highest values of all variables examined occurred during the 1960's and then fell by the second half of that decade. Since 1970, mean levels of fishing effort, target fish catches, and blue marlin landings have increased significantly, while blue marlin CPUE and B:T ratios have remained relatively stable. Concurrently, white marlin landings, CPUE, and B:T ratios have all declined. While results suggest the fishery's target species change may have been a factor in lowering white marlin bycatch, the same cannot be said for blue marlin. Relative increases in blue marlin B:T ratios off the northeastern coast of South America and in the wider eastern Atlantic are cause for concern, as are continuing trends of CPUE decline for white marlin in this data set as well as others.

Original languageEnglish
Pages (from-to)9-20
Number of pages12
JournalMarine Fisheries Review
Volume66
Issue number2
StatePublished - Dec 1 2004
Externally publishedYes

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Istiophoridae
pelagic fishery
bycatch
catch per unit effort
fisheries
Thunnus obesus
Xiphias gladius
fishery
tuna
longlining
Scombridae
fishing effort
Atlantic Ocean
Kajikia albida
Makaira nigricans
coasts
mortality
coast
ocean
fish

ASJC Scopus subject areas

  • Aquatic Science

Cite this

Atlantic blue marlin, Makaira nigricans, and white marlin, Tetrapterus albidus, bycatch of the Japanese pelagic longline fishery, 1960-2000. / Serafy, Joseph E.; Diaz, Guillermo A.; Prince, Eric D.; Orbesen, Eric S.; Legault, Christopher M.

In: Marine Fisheries Review, Vol. 66, No. 2, 01.12.2004, p. 9-20.

Research output: Contribution to journalArticle

Serafy, Joseph E. ; Diaz, Guillermo A. ; Prince, Eric D. ; Orbesen, Eric S. ; Legault, Christopher M. / Atlantic blue marlin, Makaira nigricans, and white marlin, Tetrapterus albidus, bycatch of the Japanese pelagic longline fishery, 1960-2000. In: Marine Fisheries Review. 2004 ; Vol. 66, No. 2. pp. 9-20.
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