Étude de l’incidence des blessures externes chez les cétacés des Petites Antilles, et caractérisation préliminaire des pressions anthropiques associées
propuesta de investigación
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Of the 93 known species of cetaceans, one-third are found in the Caribbean. Yet there are few large- scale scientific studies of them in this region. Besides, with 70% of the local population directly dependent on the sea (fishing, tourism) and numerous shipping lanes, cetaceans are particularly exposed to human pressures. Thanks to two years of sea expeditions and a substantial sampling effort in the Lesser Antilles, over 5,200 cetacean photographs have been collected and analyzed. The creation of a key for determining the anthropogenic or natural origin of the cetaceans’ injuries has enabled a preliminary estimate of the quantification and location of anthropogenic pressures linked to maritime traffic and fishing activities in the Lesser Antilles. Cetacean species present distinct injury profiles, with some being more marked than others by anthropogenic injuries, especially the dwarf and pygmy sperm whales (Kogia sp.) and the pygmy killer whale (Feresa attenuata), though they would require more observations. This is also the case for the melon- headed whale (Peponocephala electra), for which the level of confidence is more reasonable. In contrast, the most frequently observed species, the pantropical spotted dolphin (Stenella attenuata), is very little marked. This species can nevertheless be used as a basis for a spatial analysis of injury distribution, thanks to its resident nature on each island. However, it cannot really act as a sentinel species, as only 9% of individuals bear anthropogenic wounds. Nevertheless, the spatial distribution of wounds observed (fresh wounds and on S. attenuata, a resident species) seems to indicate that certain areas, such as Saint Vincent and the Grenadines, Saint Lucia or the French islands of Martinique and Guadeloupe, are particularly associated with high anthropogenic impacts. Finally, certain biological and ethological characteristics, such as black color, low age of sexual maturity and high maximum dive duration, seem to increase the susceptibility of being injured by human activities. This is confirmed by a Random Forest artificial intelligence model, but more balanced data across species would give greater confidence in these results. More information on the distribution and behavior of species in the Lesser Antilles, together with international cooperation, would lead to a better understanding of the threats to cetaceans, and to more effective global conservation measures.
Propuesta de TFG de maestría con doble titulación coordinada con la Maestría Académica en Gestión Integrada de Áreas Costeras Tropicales.
- Gestión Ambiental