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Endangered Species Research

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ESR 9:81-90 (2009)  -  DOI:

Effects of species misidentification on population assessment of overfished white marlin Tetrapturus albidus and roundscale spearfish T. georgii

Lawrence Beerkircher1,*, Freddy Arocha2, Ann Barse3, Eric Prince1, Victor Restrepo4, Joseph Serafy1, Mahmood Shivji5,*

1Southeast Fisheries Science Center, 75 Virginia Beach Drive, Miami, Florida 33149, USA
2Instituto Oceanografico, Universidad de Oriente, Cerro Colorado 204 Cumana, Venezuela
3Salisbury University, Department of Biological Sciences, 1101 Camden Avenue, Salisbury, Maryland 21801, USA
4International Commission for the Conservation of Atlantic Tunas, Corazón de María 8, 28002 Madrid, Spain
5Guy Harvey Research Institute, Oceanographic Center, Nova Southeastern University, 8000 N. Ocean Drive, Dania Beach, Florida 33004, USA
*‑Corresponding authors. Email: ,

ABSTRACT: The white marlin Tetrapturus albidus (Istiophoridae) is considered to be among the most overexploited species under international management jurisdiction in the Atlantic Ocean, resulting in diverse stakeholder concerns. Efforts have been made to add it to the US Endangered Species List. Its population status has become uncertain with the realization that: (1) longstanding misidentifications of white marlin have occurred with the recently recognized, morphologically similar and sympatric roundscale spearfish T. georgii; and (2) the 2 species have unknowingly been assessed and managed as a species group. We show that roundscale spearfish currently constitute a substantial proportion (~27%) of the overall ‘white marlin’ catch in the western North Atlantic, with high spatial variation within this region. Consequently, the accuracy of current biological knowledge on white marlin, some of which has formed the input for past population status modeling, is compromised by ‘contamination’ due to misidentification. Population assessment simulations in the western North Atlantic incorporating the proportion of roundscale spearfish (27%) were run; these indicated that historical changes in the ratio of the 2 species, as well as differences in the population growth rates between T. albidus and T. georgii, affect simulation results. Our findings suggest misidentifications between the species may have affected the accuracy of past T. albidus population assessments in the western North Atlantic, which therefore need re-visiting to permit improved management and recovery of this species. New collection of life history data for T. albidus and T. georgii is also recommended to corroborate the results of historical studies.

KEY WORDS: Population assessments · Roundscale spearfish · Species identification · White marlin

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Cite this article as: Beerkircher L, Arocha F, Barse A, Prince E, Restrepo V, Serafy J, Shivji M (2009) Effects of species misidentification on population assessment of overfished white marlin Tetrapturus albidus and roundscale spearfish T. georgii. Endang Species Res 9:81-90.

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