Relations between seabirds and fisheries : Albatrosses as sentinels of the Austral Ocean
The current 6th major species extinction crisis is also affecting seabirds, especially albatrosses. Their populations have decreased by 70% over the last 60 years, mainly due to mortality in longline fisheries. Large albatrosses cover enormous distances during their foraging trips and their curiosit...
| Main Author: | |
|---|---|
| Other Authors: | , , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | French |
| Published: |
HAL CCSD
2020
|
| Subjects: | |
| Online Access: | https://tel.archives-ouvertes.fr/tel-03344424 https://tel.archives-ouvertes.fr/tel-03344424/document https://tel.archives-ouvertes.fr/tel-03344424/file/2020Corbeau154598.pdf |
| Summary: | The current 6th major species extinction crisis is also affecting seabirds, especially albatrosses. Their populations have decreased by 70% over the last 60 years, mainly due to mortality in longline fisheries. Large albatrosses cover enormous distances during their foraging trips and their curiosity and opportunism favour regular encounters with boats. Thus, they constitute privileged models for studying the relationships between seabirds and fisheries. During the course of this thesis, thanks to the development of new prototype loggers deployed on Wandering and Amsterdam albatrosses in the Indian Ocean and new methods for estimating by-catch risks, we were able to observe that natural foraging behaviours differ from those associated with a boat. Similarly, the intrinsic characteristics of birds (species, population, sex, age and personality) lead to differences in exposure to by-catch risk, particularly through the use of different habitats. Finally, we have shown that the characteristics of boats also have a strong influence on the risk of by-catch, in particular through the type of boats encountered, their legality, the fishing practices used and the presence of discards. We conclude by presenting new methods to better estimate the risks of by-catch and the need for fundamental knowledge of species and populations in order to better protect marine environments that are increasingly endangered. La 6ème crise majeure d’extinction des espèces qui sévit actuellement n’épargne pas les oiseaux marins, notamment les albatros. Leurs populations ont chuté de 70% au cours des 60 dernières années essentiellement par mortalité dans les palangriers. Les grands albatros couvrent d’énormes distances pendant leurs trajets de recherche alimentaire et leur curiosité et leur opportunisme favorisent les rencontres régulières avec des bateaux. Ils constituent ainsi des modèles privilégiés pour étudier les relations entre les oiseaux marins et les pêcheries. Au cours de cette thèse, grâce au développement de nouveaux prototypes ... |
|---|