News News

Impact of fisheries on sea turtles

The bycatch of sea turtles by industrial fisheries is receiving an increasing attention in recent years due to the high impact it causes on these endangered species. This issue was evaluated in southern Spain waters that harbors an important feeding ground of loggerhead and leatherback turtles, including the endangered Eastern Atlantic loggerhead population. To quantify the impact that different fisheries represents to sea turtles, 272 fishermen answered to detailed illustrated questionnaires in all the main ports of Andalusia and Murcia (Spain) during 2014. This study has updated the knowledge of turtle bycatch in the southwestern Mediterranean revealing a widespread impact of fisheries on sea turtles. Fishermen recognized an annual catch of 2.3 turtles per boat. Considering the census of industrial fishing boats in the study area (1182), more than 2840 sea turtles could be bycaught per year in the study area. Most of captures (96.2%) were produced during the summer. These results suggest a severe impact of most of legal fisheries (surface longline, pursue seine, trawling and small scale fisheries) on loggerhead feeding grounds in the southwestern Mediterranean. Fishermen suggests that drift fishing conducted by foreign or illegal fishermen and almadrabas are also causing a significant bycatch of turtles. Several measures such as reviewing compliance of current fishing and environmental regulations, modifying turtle technics to reduce turtle bycatch (e.g. reduction of the use of squid as bait and disposal of hooks deeper in the water column), facilitating the rescue and handle of wound turtles and their transport to the port for recovery, and recognizing the efforts of anglers to perform a more sustainable fishing, are recommended to mitigate this impact. informacion[at]ebd.csic.es: Marco et al (2020) Sea turtle bycatch by different types of fisheries in southern Spain. Basic and Applied Herpetology https://doi.org/10.11160/bah.187


http://ojs.herpetologica.org/index.php/bah/article/view/187
Average (0 Votes)

Latest News Latest News

Back

Differences in selection of microhabitats and nest materials in three ground-nesting birds

Differences in selection of microhabitats and nest materials in three ground-nesting birds

Camouflage is a widespread strategy to avoid predation and is of particular importance for animals with reduced mobility or those in exposed habitats. Camouflage often relies on matching the visual appearance of the background, and selecting fine-scale backgrounds that complement an individual's appearance is an effective means of optimising camouflage. It was investigated whether there was an active selection of microhabitats and nest materials in three ground-nesting birds (pied avocet, Kentish plover, and little tern) to camouflage their eggs using avian visual modelling. Plovers and avocets selected substrates in which their eggs were better camouflaged, and that choice was done at an individual level. Terns have lighter, less spotted eggs, and while they did select lighter background than the other species, their eggs were a poor match to their backgrounds. The worse matching of the tern eggs was likely due to a compromise between thermal protection and camouflage because they breed later, when temperatures are higher. Finally, the addition of nest materials improved egg camouflage in terms of luminance, although the materials reduced pattern matching, which may be associated with the different roles that the nest materials play. Active selection of substrates at an individual level may be crucial to improve nest success in species that nest in exposed sites. informacion[at]ebd.csic.es: Gómez et al (2018) Individual egg camouflage is influenced by microhabitat selection and use of nest materials in ground-nesting birds. Behav Ecol Sociobiol 72:142 https://doi.org/10.1007/s00265-018-2558-7