Effects of winter fishery activities on resting numbers, food and body condition of large gulls Larus argentatus and L. marinus in the south-eastern North Sea

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 194:241-247 (2000) - doi:10.3354/meps194241 Effects of winter fishery activities on resting numbers, food and body condition of large gulls Larus argentatus and L. marinus in the south-eastern North Sea O. Hüppop*, S. Wurm Institut für Vogelforschung ŒVogelwarte Helgoland¹, Inselstation, PO Box 1220, 27494 Helgoland, Germany *E-mail: o.hueppop-ifv@t-online.de ABSTRACT: C Influences of fishery activities on herring gulls and great black-backed gulls (Larus argentatus, L. marinus) wintering on the island of Helgoland, south-eastern North Sea, were studied. When cod fishery discards were available close to the island, 83 to 87% of the gulls¹ pellets contained fishery discard remains and 70 to 73% of all pellets consisted exclusively of these. At times when no nearby trawling took place (Christmas/New Year), numbers of herring gulls dropped by up to 86% and numbers of great black-backed gulls by up to 80%. Similar declines were observed during a trawling moratorium in February 1998. Adults of both gull species had a significantly lower body mass during periods of no fishing around the island (13 and 24% less, respectively). Retraps of single gulls support these findings. The results show for the first time a strong influence of discard availability on numbers and body condition of large gulls wintering in the south-eastern North Sea. Effects on gull winter mortality and thus on population dynamics can be assumed. KEY WORDS: Fisheries · Herring gull · Great black-backed gull · Resting numbers · Food · Fishery discards · Body condition · North Sea Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 194. Publication date: March 17, 2000 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 2000 Inter-Research.