The artisanal elasmobranch fishery on the east coast of Baja California, Mexico: Characteristics and management considerations

The Mexican elasmobranch fishery ranks among the most important in the world, but details associated with fishing effort and species composition are generally unavailable, particularly for the extensive artisanal fishery. Seasonal surveys were conducted during 1998–1999 in the state of Baja Califor...

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Main Authors: WD Smith, JJ Bizzarro, GM Cailliet
Format: Article
Language:English
Published: Universidad Autónoma de Baja California 2009-06-01
Series:Ciencias Marinas
Subjects:
Online Access:https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/1534
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author WD Smith
JJ Bizzarro
GM Cailliet
author_facet WD Smith
JJ Bizzarro
GM Cailliet
author_sort WD Smith
collection DOAJ
description The Mexican elasmobranch fishery ranks among the most important in the world, but details associated with fishing effort and species composition are generally unavailable, particularly for the extensive artisanal fishery. Seasonal surveys were conducted during 1998–1999 in the state of Baja California to determine the extent and activities of the artisanal elasmobranch fishery along its Gulf of California coast. Artisanal fishermen were highly opportunistic, and temporally switched targets depending on the local abundance of teleost, invertebrate, and elasmobranch fisheries resources. At least 17 species of shark, 13 species of ray, and 2 species of skate were identified among the 4495 specimens observed. Small, coastal sharks and rays were typically landed with bottom set gillnets during all surveyed seasons (spring–autumn) and large sharks were targeted with surface set (drift) gillnets during summer and autumn. Sharks and rays contributed similarly to elasmobranch landings, comprising 50.9% and 48.3%, respectively, of the total recorded catch. Overall landings were dominated by mustelid sharks (Mustelus henlei, Mustelus spp.) and the shovelnose guitarfish (Rhinobatos productus), with Alopias pelagicus, Gymnura spp., Heterodontus mexicanus, Mobula munkiana, Myliobatis californica, and Squatina californica also representing important components of the landings. Alopias vulpinus had previously been unreported for the Gulf of California and a new maximum size record was documented for Myliobatis longirostris. Catch rates (mean elasmobranchs/vessel/trip ± standard error) were lowest during autumn (17.4 ± 3.9) and highest in spring (35.3 ± 14.1). Adult, commonly gravid, A. pelagicus, Carcharhinus falciformis, and R. productus females comprised a disproportionately greater component of the landings than did their male counterparts. Given the decades of largely unrestricted exploitation of elasmobranchs in Mexican waters, population declines and shifts in size structure are likely to have occurred among those species with the lowest fecundity and latest ages at maturity. 
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spelling doaj.art-b1c40a6e728e40eba41924fe684113a12024-03-03T18:14:13ZengUniversidad Autónoma de Baja CaliforniaCiencias Marinas0185-38802395-90532009-06-0135210.7773/cm.v35i2.1534The artisanal elasmobranch fishery on the east coast of Baja California, Mexico: Characteristics and management considerationsWD Smith0JJ Bizzarro1GM Cailliet2Oregon State UniversityMoss Landing Marine LaboratoriesMoss Landing Marine Laboratories The Mexican elasmobranch fishery ranks among the most important in the world, but details associated with fishing effort and species composition are generally unavailable, particularly for the extensive artisanal fishery. Seasonal surveys were conducted during 1998–1999 in the state of Baja California to determine the extent and activities of the artisanal elasmobranch fishery along its Gulf of California coast. Artisanal fishermen were highly opportunistic, and temporally switched targets depending on the local abundance of teleost, invertebrate, and elasmobranch fisheries resources. At least 17 species of shark, 13 species of ray, and 2 species of skate were identified among the 4495 specimens observed. Small, coastal sharks and rays were typically landed with bottom set gillnets during all surveyed seasons (spring–autumn) and large sharks were targeted with surface set (drift) gillnets during summer and autumn. Sharks and rays contributed similarly to elasmobranch landings, comprising 50.9% and 48.3%, respectively, of the total recorded catch. Overall landings were dominated by mustelid sharks (Mustelus henlei, Mustelus spp.) and the shovelnose guitarfish (Rhinobatos productus), with Alopias pelagicus, Gymnura spp., Heterodontus mexicanus, Mobula munkiana, Myliobatis californica, and Squatina californica also representing important components of the landings. Alopias vulpinus had previously been unreported for the Gulf of California and a new maximum size record was documented for Myliobatis longirostris. Catch rates (mean elasmobranchs/vessel/trip ± standard error) were lowest during autumn (17.4 ± 3.9) and highest in spring (35.3 ± 14.1). Adult, commonly gravid, A. pelagicus, Carcharhinus falciformis, and R. productus females comprised a disproportionately greater component of the landings than did their male counterparts. Given the decades of largely unrestricted exploitation of elasmobranchs in Mexican waters, population declines and shifts in size structure are likely to have occurred among those species with the lowest fecundity and latest ages at maturity.  https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/1534CPUEGulf of Californiaelasmobranchssize composition
spellingShingle WD Smith
JJ Bizzarro
GM Cailliet
The artisanal elasmobranch fishery on the east coast of Baja California, Mexico: Characteristics and management considerations
Ciencias Marinas
CPUE
Gulf of California
elasmobranchs
size composition
title The artisanal elasmobranch fishery on the east coast of Baja California, Mexico: Characteristics and management considerations
title_full The artisanal elasmobranch fishery on the east coast of Baja California, Mexico: Characteristics and management considerations
title_fullStr The artisanal elasmobranch fishery on the east coast of Baja California, Mexico: Characteristics and management considerations
title_full_unstemmed The artisanal elasmobranch fishery on the east coast of Baja California, Mexico: Characteristics and management considerations
title_short The artisanal elasmobranch fishery on the east coast of Baja California, Mexico: Characteristics and management considerations
title_sort artisanal elasmobranch fishery on the east coast of baja california mexico characteristics and management considerations
topic CPUE
Gulf of California
elasmobranchs
size composition
url https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/1534
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