Diet of Mediterranean monk seals (Monachus monachus).
Edridge A1, 1, Pierce G J1, Santos M B1, Dendrinos P2, Psaradelli M2, Tounta E2, & Androukaki E2
1School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
2MOm/ Hellenic Society for the Study and Protection of the Monk Seal, 18 Solomou Str. GR-10682 Athens, Greece
The Mediterranean monk seal is a critically endangered species facing a range of threats including fishery interactions. Its diet was investigated as part the LIFE project "Monk Seal and Fisheries: Mitigating the conflict in the Greek Seas". Stomach contents were obtained from 27 carcasses collected in Greece between 1997 and 2008, including males and females, pups and adults. In total, 530 prey items from 71 species were identified, including 266 cephalopods (50%), 253 fish (48%), and a few other molluscs (1.6%) and crustaceans (0.4%). Faecal samples were collected but contained no identifiable prey remains. Octopuses, Octopus vulgaris (34% by number) and Eledone cirrhosa (11%), were the most numerous prey and probably form the largest part of prey biomass. Fish of the families Sparidae (28%) and to a lesser extent Scorpaenidae (3%), Congridae (2.5%) and Atherinidae (2.5%) were also numerically important. Most prey species were of commercial importance in fisheries. Multivariate analysis (redundancy analysis, RDA) suggested that diet varied according to cause of death and seasonally, although statistical significance was marginal (reflecting the small sample size). Sparids occurred more frequently in deliberately killed animals than in those that died naturally. The small population size of monk seals means that their total consumption of fish and cephalopods in the Mediterranean is rather low. However, the fact that nine (1/3) of the animals sampled had been deliberately killed and the predominance of commercial fish species in the stomach contents confirm the high probability of interactions between monk seals and commercial fishing activities.