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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
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Firebreaks constrain butterfly movements

Firebreaks constrain butterfly movements

Firebreaks are linear strips that dissect the landscape and prevent or mitigate the spread of wildfires in Mediterranean landscapes. However, few studies have addressed their potential effect on insect behavior. The lack of traffic and other human activities in firebreaks makes them suitable for testing the sole effect of physical habitat disruption on animal movement. Main objective was to evaluate whether the pattern of movement by a butterfly species was affected by this landscape element. Flight trajectories of the lycaenid butterfly Plebejus argus were reconstructed within and around one firebreak using visual and GPS tracking in Doñana National Park (southern Spain). Butterflies that were active at the firebreak boundary often refused to enter the firebreak and, when they did, most individuals returned before reaching the opposite side. Inside the firebreak faster and straighter trajectories were recorded than in adjacent scrubland areas. Butterflies that crossed the firebreak headed the most favorable direction to minimize the time spent within the habitat discontinuity. At the landscape scale, firebreak density increased in areas where P. argus habitat was more fragmented and had lower quality. In other studies, when firebreaks are mowed instead of ploughed, they appeared to be beneficial for butterflies. In contrast, in Doñana, barren firebreaks do not provide any valuable resource for P. argus and its environmental conditions probably entail considerable physiological stress. In sum, a narrow, open linear element lacking any human activity induces a marked change in the movement behavior of a butterfly species, with potential consequences on population dynamics at the landscape scale. Therefore, firebreaks used for protecting Mediterranean landscapes could have side effects on animal populations other than localized habitat loss due to mere vegetation removal. informacion[at]ebd.csic.es: Fernández et al (2019) Firebreaks as a barrier to movement: the case of a butterfly in a Mediterranean landscape. J Insect Conserv DOI 10.1007/s10841-019-00175-5


https://link.springer.com/article/10.1007%2Fs10841-019-00175-5#Abs1