MEPS 277:263-274 (2004)  -  doi:10.3354/meps277263

Seasonal distribution of minke whales Balaenoptera acutorostrata in relation to physiography and prey off the Isle of Mull, Scotland

Kelly Macleod1,2,*, Richard Fairbairns3, Alison Gill3, Brenan Fairbairns3, Jonathan Gordon1,2, Chris Blair-Myers4, Edward C. M. Parsons1

1Hebridean Whale and Dolphin Trust, Main Street, Tobermory, Isle of Mull PA75 6NU, UK
2Sea Mammal Research Unit, University of St. Andrews, St. Andrews, Fife KY16 8LB, UK
3Sea Life Surveys, Ledaig, Tobermory, Isle of Mull PA75 6NU, UK
4 Kent County Council, Maidstone, Kent ME14 1XQ, UK
*Present address: St. Andrews. Email:

ABSTRACT: Sightings of minke whales Balaenoptera acutorostrata were recorded in waters off the Isle of Mull between March and November each year from 1992 to 1999. Survey effort amounted to 42342.5 km, and 850 minke whale encounters were recorded. Data were analysed in relation to undersea topography and seabed sediment type using multiple logistic regression. The effect of potential minke whale prey distribution was inferred from maps predicting suitable habitats for the lesser sandeel Ammodytes marinus and herring Clupea harengus constructed using a Geographical Information System (GIS). Whale distribution changed with season, and this may be a response to a shift in prey preferences. In spring, sediment type was a significant predictor of whale presence and sightings predominated over mixtures of gravel/sand seabed sediments. This distribution closely matched that of the sandeel, which is dependent on suitable winter settlement grounds. Throughout summer, the distribution of the minke whale underwent considerable change. In June, minke whales were predominately distributed over the sandeel habitat, but in July they dispersed to the predicted pre-spawning herring habitat, clustering in that area by August. In the waters around Mull, shifts in prey distribution and abundance occur between March and November and are the most likely factor governing the distribution and abundance of the minke whale.


KEY WORDS: Minke whale · Bathymetry · Seabed sediment · Herring · Sandeel · Geographical Information System


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