首页 | 本学科首页   官方微博 | 高级检索  
     


Characterizing environmental and spatial variables associated with the incidental catch of olive ridley (Lepidochelys olivacea) in the Eastern Tropical Pacific purse‐seine fishery
Authors:Jose T. Montero  Raul O. Martinez‐Rincon  Selina S. Heppell  Martin Hall  Michael Ewal
Affiliation:1. Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Catolica de Chile, Santiago, Chile;2. Centro de Investigaciones Biológicas del Noroeste (CIBNOR), CONACYT Research Fellow, La Paz, Mexico;3. Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, U.S.A;4. Inter American Tropical Tuna Commission, La Jolla, CA, U.S.A;5. Geomatic Research, Corvallis, OR, U.S.A
Abstract:In the Eastern Tropical Pacific (ETP), a region of high fishing activity, olive ridley (Lepidochelis olivacea) and other sea turtles are accidentally caught in fishing nets with tuna and other animals. To date, the interaction between fishing activity, ocean conditions and sea turtle incidental catch in the ETP has been described and quantified, but the factors leading to the interaction of olive ridleys and fishing activity are not well understood. This information is essential for the development of future management strategies that avoid bycatch and incidental captures of sea turtles. We used Generalized additive models (GAM) to analyze the relationship between olive ridley incidental catch per unit effort (iCPUE) in the ETP purse‐seine fisheries and environmental conditions, geographic extent and fishing set type (associated with dolphins, floating objects or in free‐swimming tuna schools). Our results suggest that water temperature, set type and geographic location (latitude, longitude and distance to nesting beaches) are the most important predictor variables to describe the probability of a capture event, with the highest iCPUE observed in sets made over floating objects. With the environmental predictors used, sea surface temperatures (SST) of 26–30°C and chlorophyll‐a (chl‐a) concentrations <0.36 mg m?3 were associated with the highest probability of an incidental catch. Temporally, the highest probability of an incidental catch was observed in the second half of the year (June to December). Four regions were observed as high incidental catch hotspots: North and south of the equator between 0–10°N; 0–10°S and from 120 to 140°W; and along the Colombian coast and surrounding regions.
Keywords:Eastern Tropical Pacific  General Additive Model  incidental catch  Inter American Tropical Tuna Commission  olive ridley  purse‐seine  spatial prediction
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号