Seasonal distribution and abundance of cetaceans within French waters- Part II: The Bay of Biscay and the English Channel

摘要: Abstract From the Habitat Directive to recent Marine Strategy Framework Directive, conservation status of cetaceans in European water has been concern for over two decades. In this study, a seasonal comparison abundance and distribution was carried out contrasted regions Eastern North Atlantic, Bay Biscay English Channel. Estimates were obtained sub-regions (375,000 km²) from large aerial surveys conducted winter (November 2011 February 2012) summer (May August 2012). The most abundant species encountered Channel, harbour porpoise, displayed strong variations its but stable (18,000 individuals, CV=30%). Biscay, patterns common / striped dolphins varied 285,000 individuals (95% CI: 174,000–481,000) winter, preferentially distributed close shelf break, 494,000 342,000−719,000) beyond break summer. Baleen whales also exhibited an increase their density Seasonal abundances bottlenose quite stable, with number ‘pelagic’ encounters offshore winter. No significant difference estimated pilot sperm whale. These provided baseline estimates inform policies be developed, or existing instruments such as Habitats Directive. addition, our results supported hypothesis shift distributions some porpoise minke whale waters.