Minke Whale – Balaenoptera acutorostrata
Size: max 9.8 m
Key feature: Blow hole and dorsal fin visible together
Behaviour: Breaching and distinctive dive
Minke whales are the smallest of the Rorqual whales. Rorqual is the folds of skin under the lower jaw, which allows the mouth to expand when taking in large amounts of water to sieve through the baleen for food. The appearance is variable and sub species of Minke whale occur. They have a dark dorsal side and a white underbelly with a grey “smoky” pattern on its flanks. If spotted breaching, Minke whales can be distinguished by the white band on their flippers; however this can be variable in size, and sometimes be absent. They have a small sickle shaped dorsal fin, two thirds of the way down their back, this can be seen at the same time as the blow hole.
Minke whales tend to move unpredictably, sometimes they are inquisitive and approach boats, however mainly are hard to see. Their dive is distinctive and is often the key to identifying the animals; first the streamline head appears, followed by the blow hole, the blow can reach 3 m, but is often hard to make out, the dorsal fin follows and can be seen at the same time as the blow hole. As the whales dive downwards the tail stock arches but the flukes remain below the surface. The Minke whale often breaches, revealing its tell-tale striped flippers. They are usually solitary animals, but when feeding can be seen in groups of up to 10 individuals.
The Minke whale is the most abundant rorqual whale. It has a worldwide distribution, but consists of different species; a common Minke and an Antarctic Minke, within the common Minke, different sub-species exist. Some of the populations of Minke whale migrate throughout the year. Minke whales can be seen from the Isle of Mull to the west of Scotland. They have also been seen on ORCA surveys to the Bay of Biscay and through the North Sea.
Minke whales are one of many species which have been put under threat by commercial whaling, their name even originated from a 18th century Norwegian whaler. They were commercially hunted by a number of countries until the 1980s. However hunting of minke whales continue today with Japan, Iceland, and Norway continuing to hunt Minke whales. Japan catch whales for “scientific research” then commercially process the whale carcasses after the research has taken place. As well as whaling, threats which impact all cetaceans such as pollution, reduction of prey by over fishing and bycatch apply to Minke whales. There have also been numerous records of ship collisions causing fatalities of Minke whales in UK waters.