engleski

Rconstructing past and present behaviours, occurrence and seasonality of elasmobranch species through the recovery of local ecological knowledge

Elasmobranchs constitute a target or bycatch of a wide variety of fishing techniques. Such anthropogenic pressure has brought to a drastic reduction of local populations across the Mediterranean Sea. Moreover, limited - data collection and species misidentif ication, among others, have led to a scarcity of historical data on species occurrence and abundance trends in several taxa. Such information is particularly valuable to study migration dynamics and behavior variations, as well as to reconstruct historical trends. To fill this data gap, the use of local ecological knowledge from professional fishermen can be considered as a valuable source of semi - quantitative information on several aspects of species ecology, abundance and behavioral aspects. Through a questionnaire survey, fishermen operating with diverse fishing gears such as bottom and pelagic trawlers, set nets and longlines were interviewed by trained researchers with the aid of photo - identification materials. A total of 211 interviews were collected across nine Mediterranean FAO - GSA sub - areas (9, 10, 11, 16, 17, 18, 19, 22, 28). Results covered a wide range of elasmobranch species with regard to coastal, pelagic and deep - sea environment. Interviewers indicated species that were abundant in the past, declined recently and showed size variation compared to past catches. Moreover, fishermen reported aggregation sightings/events, seasonal movements and species - specific fishing area. The present study constitutes a baseline regarding abundance and distribution of elasmobranch species in historical times and may represent a valuable tool for data deficient taxa. It also gives new insights on elasmobranchs behavioral and ecological aspects and highlights priority species and suitable geographic areas for conservation and behavioral studies.

Fishery ; Elasmobranch species ; Aggregations ; Mediterranean Sea

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