Species biology of elasmobranch by-catch in bottom-trawl fishery on the northern Patagonian shelf, Argentina

Ac Crespi-Abril,Sn Pedraza,Na García,Ea Crespo

doi:10.3354/ab00535

Abstract

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 19:239-251 (2013) - DOI: https://doi.org/10.3354/ab00535 Species biology of elasmobranch by-catch in bottom-trawl fishery on the northern Patagonian shelf, Argentina A. C. Crespi-Abril*, S. N. Pedraza, N. A. García, E. A. Crespo Centro Nacional Patagónico (CONICET), Boulevard Brown s/n, Puerto Madryn, Chubut 9120, Argentina *Email: crespi@cenpat.edu.ar ABSTRACT: The present study analyzes the species composition of elasmobranch by-catch of bottom trawlers that targeted common hake Merluccius hubbsi on the northern and central Patagonian shelf during 2001, 2002 and 2003. Six surveys were conducted, and a total of 20 species of elasmobranchs were observed. Zearaja chilensis and Squalus acanthias were present in all surveys. The mean values of relative abundance ranged between 9.12 and 151 ind. km-2 for Z. chilensis and between 8.24 and 298 ind. km-2 for S. acanthias. Bathyraja brachyurops, B. macloviana, B. magellanica, Discopyge sp. and Psammobatis lentiginosa were registered only in 1 survey, and their relative abundance did not exceed 15 ind. km-2. There were no patterns detected between the mean size of the individuals and the depth of capture for any of the captured species. Length-to-weight relationships were estimated for 14 species, and size-at-maturity was estimated for 8 species. KEY WORDS: By-catch · Size-at-maturity · Elasmobranchs · Length-to-weight relationships Full text in pdf format PreviousNextCite this article as: Crespi-Abril AC, Pedraza SN, García NA, Crespo EA (2013) Species biology of elasmobranch by-catch in bottom-trawl fishery on the northern Patagonian shelf, Argentina. Aquat Biol 19:239-251. https://doi.org/10.3354/ab00535 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 19, No. 3. Online publication date: October 24, 2013 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2013 Inter-Research.

Highlights

Despite the key role that elasmobranchs play in ecosystems, the basic biological information needed for responsible management is lacking for many species, including minimum, maximum and average sizes, age-at-maturity estimations and lengthto-weight relationships
The major abundances of Z. chilensis were observed in autumn and winter, and the major abundances of S. acanthias were observed in winter and spring (Table 2)
Concern about the current status of elasmobranch populations has increased among researchers, and several studies have been conducted to address this topic (IUCN 2003)

Summary

Introduction

Despite the key role that elasmobranchs play in ecosystems, the basic biological information needed for responsible management is lacking for many species, including minimum, maximum and average sizes, age-at-maturity estimations and lengthto-weight relationships These data are essential for understanding growth rate, age structure and other aspects of elasmobranch population dynamics. The first step in this plan was to carefully review the available information on several species and to identify knowledge gaps in order to determine key lines of research (Perez Comesaña et al 2011) In this context, the amount of information available and the number of works published increased significantly (Lasta 2003, Colonello et al 2011, Perez Comesaña et al 2011) in an effort to increase baseline information on elasmobranchs. Several of these studies involved the analysis of reproductive and trophic characteristics (Lucifora et al 1999, Koen Alonso et al 2001, Crespi-Abril et al 2003, Elías et al 2005, Ruocco et al 2006, Scenna 2011)

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