The minke whale (Balaenoptera acutorostrata), while still being one of the largest animals you might be likely to see in British waters, is actually the smallest of the rorqual whales. Their dark-grey skin covering the top half of their body is contrasted with a much lighter underside, and a single white “arm band” is usually visible on each of their flippers. Adult males typically reach a length of 6.7 – 9.8m, female adults average out at around 7.3 – 10.7m; and their typical weight can be anything from 8 to 13 tonnes.
IUCN Least Concern
As they’re the most abundant rorqual whale species, the International Union for the Conservation of Nature (IUCN) Red List has it classified as Least Concern (LC), in terms of its conservation status. They are listed on Appendix I of CITIES throughout the world, with the only exception of Greenland, where it is instead listed under Appendix II.
Where to find them:
B. acturostrata have recently (summer, 2012) been spotted just out of the mouth of the river Mersey by Liverpool Bay Marine Life Trust staff, and Sea Watch community sighting records list reports of them off the coast of Blackpool in recent years, prior to this.
They’re known to occupy both coastal and off-shore waters, preferring cooler areas at higher latitudes during the summer, and moving into warmer waters, at lower latitudes during the winter; on the whole – some areas are known to have year-round populations, however; we’d be interested to find out whether our own, local specimens behave in such as way, much as at least part of our Harbour Porpoise (Phocoena phocoena) population does.
Minkes are baleen whales, meaning that they filter water through their baleen plates, to sieve out invertebrates and small fish. Throughout the north Atlantic, their diet consists of largely sand lace, sand eel, salmon (a species that we’re currently seeing an exciting resurgence in, locally), capelin, mackerel (something that we have in great abundance, in this region in particular), cod, whiting, sprat, wolffish, dogfish, pollack, haddock, herring, euphasiids (krill and the like) and copepods (very small crustaceans and assorted planktonic species).
So far, in this region, minke whales have only been spotted individually, and they are largely a solitary species; but they are often seen feeding in pairs. They’ve been known to trap shoals of fish against the surface of the water, which they can take advantage of due to their surprising manoeuvrability.
Did you know Liverpool Bay Marine Life Trust volunteers spotted a minke whale leaving the River Mersey in summer 2012?