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(1 - 3 of 3)
- Title
- Temporal variation in the artisanal elasmobranch fishery of Sonora, Mexico,
- Description
- Baseline, species-specific information is largely unavailable for artisanal elasmobranch fisheries, but is essential for the monitoring of exploited populations and the development of effective management plans. Seasonal surveys were conducted during 1998-1999 in Sonora, Mexico to determine the extent and activities of artisanal elasmobranch fisheries operating in the eastern Gulf of California. Nineteen fishing sites were documented, the majority of which (84.2%) targeted elasmobranchs during some part of the year. Most small demersal sharks and rays were landed in bottom set gillnet fisheries that also targeted demersal teleosts, whereas large sharks were usually taken in directed surface longline or, to a lesser extent, drift gillnet fisheries. Rays numerically dominated sampled landings in Sonora (63.4%, n = 100,136), and catch rates exceeded those of sharks during spring and summer months. The shovelnose guitarfish, Rhinobatos productus, was the primary fishery target during these seasons. During autumn, small sharks, especially mustelids (Mustelus spp.) were numerically dominant, but rays (e.g., Dasyatis dipterura) were also caught in large numbers. Winter landings in Sonora were principally composed of mustelid sharks, which represented the greatest seasonal catch rates of all elasmobranch taxa during this study. Large sharks were of comparably minor importance, with a limited summer fishery operating in the southern part of the state. Variation in catch composition was evident in association with differential interannual environmental conditions (El Niño and La Niña) and seasonal temperature fluctuations. Size composition of landings varied greatly by species, but relatively small size classes of sharks and rays were abundant and large, often gravid females of several ray species (e.g., R. productus and Narcine entemedor) supported spring and summer fisheries in nearshore waters. Populations of many large shark species (e.g., Carcharhinus leucas, Carcharhinus limbatus, Carcharhinus obscurus and Galeocerdo cuvier) have likely been overfished, prompting a shift in effort towards coastal populations of smaller elasmobranchs. © 2009 Elsevier B.V. All rights reserved., Cited By (since 1996):13, Fish and Fisheries, CODEN: FISRD, ,
- Author
- Bizzarro, Smith, Márquez-Farías, Tyminski, Hueter
- Date
- 2009-01-01T00:00:00Z
- Title
- The seasonal importance of small coastal sharks and rays in the artisanal elasmobranch fishery of Sinaloa, Mexico,
- Description
- Seasonal surveys were conducted during 1998-1999 in Sinaloa, Mexico to determine the extent and activities of the artisanal elasmobranch fishery operating in the southeastern Gulf of California. Twenty-eight fishing sites were documented, the majority of which (78.6%) targeted elasmobranchs during some part of the year. Sharks numerically dominated sampled landings (65.0%, n = 2390), and catch rates exceeded those of rays during autumn-spring. The scalloped hammerhead, Sphyrna lewini, was the primary fishery target during these seasons, with most landings composed of early life stages. During summer, rays, especially Rhinoptera steindachneri, were numerically dominant (87.7%). Large sharks were of comparably minor importance in the artisanal fishery during all seasons. Catch composition was similar between spring and winter (SIMobs = 0.393, SIMexp = 0.415; P = 0.25), largely because the fishery mainly targeted "cazón" (sharks < 1.5 m total length) during this period (e.g., S. lewini, Rhizoprionodon longurio). Small size classes of large sharks and a wide size range of coastal sharks and rays were primarily observed. In addition, size composition of S. lewini and to a lesser extent, R. longurio decreased significantly between historic and contemporary landings. Local populations of these species should therefore be closely monitored., Cited By (since 1996):2, Fish and Fisheries, Source: Scopus, ,
- Author
- Bizzarro, Smith, Castillo-Géniz, Ocampo-Torres, Márquez-Farías, Hueter
- Date
- 2009-01-01T00:00:00Z
- Title
- Artisanal fisheries and reproductive biology of the golden cownose ray, Rhinoptera steindachneri Evermann and Jenkins, 1891, in the northern Mexican Pacific,
- Description
- The golden cownose ray, Rhinoptera steindachneri, was one of the most abundant species landed in artisanal elasmobranch fisheries in the northern Gulf of California (Baja California and Sonora) and Bahía Almejas, Mexico during 1998-1999. In the northern Gulf of California, R. steindachneri was most frequently observed during summer months (11.4% of elasmobranch landings, catch per unit effort (CPUE) = 6.8 individuals/vessel trip) and was rare during winter (0.1%, CPUE = 0.1). In Bahía Almejas, its relative abundance was greater during August (5.2%) than June (0.3%), a trend also evident in CPUE (August = 1.2, June = 0.1). The mean size of R. steindachneri landed in the Gulf of California was 64.3 ± 12.8 (S.D.) cm disc width (DW). Median size at maturity for Gulf of California specimens was similar for females (70.2 cm DW) and males (69.9 cm DW). Fecundity was found to be one offspring per female, with parturition estimated to occur from late June-August. Size at birth was estimated at 38-45 cm DW after a gestation period of approximately 11-12 months. Greater maximum sizes (to 104 cm DW) and embryo sizes (to 43 cm DW) were observed in Bahía Almejas. The large size at maturity, low fecundity, and long gestation period determined for R. steindachneri indicate that this species could be particularly susceptible to overexploitation. © 2006 Elsevier B.V. All rights reserved., Cited By (since 1996):20, Fish and Fisheries, CODEN: FISRD, ,
- Author
- Bizzarro, Smith, Márquez-Farías, Hueter
- Date
- 2007-01-01T00:00:00Z