Cetacean abundance and distribution in European Atlantic shelf waters to inform conservation and management

• Published in: Biological Conservation
• Main Authors: Hammond, Philip Steven, Macleod, Kelly, Berggren, Per, Borchers, David Louis, Burt, M Louise, Cañadas, Ana, Desportes, Genevieve, Donovan, Greg P, Gilles, Anita, Gillespie, Douglas Michael, Gordon, Jonathan Charles David, Hiby, Lex, Kuklik, Iwona, Leaper, Russell, Lehnert, Kristina, Leopold, Mardik, Lovell, Philip, Øien, Nils, Paxton, Charles G. M., Ridoux, Vincent, Rogan, Emer, Samarra, Filipa Isabel Pereira, Scheidat, Meike, Sequeira, Marina, Siebert, Ursula, Skov, Henrik, Swift, Rene James, Tasker, Mark, Teilmann, Jonas, Van Canneyt, Olivier, Vázquez, José Antonio
• Other Authors: NERC, University of St Andrews. School of Biology, University of St Andrews. Scottish Oceans Institute, University of St Andrews. Centre for Research into Ecological & Environmental Modelling, University of St Andrews. Marine Alliance for Science & Technology Scotland, University of St Andrews. Sea Mammal Research Unit, University of St Andrews. School of Mathematics and Statistics, University of St Andrews. Sound Tags Group, University of St Andrews. Bioacoustics group, University of St Andrews. St Andrews Sustainability Institute
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2013
• Subjects: Conservation status; North Sea; Line transect sampling; SCANS; Harbour porpoise; Bottlenose dolphin; Common dolphin; White-beaked dolphin; Minke whale; Bycatch; Habitats Directive; QH301 Biology; QH301; minke whale
• Online Access: https://hdl.handle.net/10023/3859; https://doi.org/10.1016/j.biocon.2013.04.010

This article was made open access through BIS OA funding. The European Union (EU) Habitats Directive requires Member States to monitor and maintain at favourable conservation status those species identified to be in need of protection, including all cetaceans. In July 2005 we surveyed the entire EU Atlantic continental shelf to generate robust estimates of abundance for harbour porpoise and other cetacean species. The survey used line transect sampling methods and purpose built data collection equipment designed to minimise bias in estimates of abundance. Shipboard transects covered 19,725 km in sea conditions ⩽Beaufort 4 in an area of 1,005,743 km2. Aerial transects covered 15,802 km in good/moderate conditions (⩽Beaufort 3) in an area of 364,371 km2. Thirteen cetacean species were recorded; abundance was estimated for harbour porpoise (375,358; CV = 0.197), bottlenose dolphin (16,485; CV = 0.422), white-beaked dolphin (16,536; CV = 0.303), short-beaked common dolphin (56,221; CV = 0.234) and minke whale (18,958; CV = 0.347). Abundance in 2005 was similar to that estimated in July 1994 for harbour porpoise, white-beaked dolphin and minke whale in a comparable area. However, model-based density surfaces showed a marked difference in harbour porpoise distribution between 1994 and 2005. Our results allow EU Member States to discharge their responsibilities under the Habitats Directive and inform other international organisations concerning the assessment of conservation status of cetaceans and the impact of bycatch at a large spatial scale. The lack of evidence for a change in harbour porpoise abundance in EU waters as a whole does not exclude the possibility of an impact of bycatch in some areas. Monitoring bycatch and estimation of abundance continue to be essential. Peer reviewed