THE MINKE WHALE Balaenoptera acutorostrata

 

Recognition:

Small whale with a sharply pointed snout. Low "blow" (visible exhalation). Relatively short flippers (1/8 body length) with diagonal white band above. Colour: dark grey-black back, white on belly and underside of flippers.
Length: female about 8.5m; male about 8.9m.
Weight: approx. 10 tonnes.

The minke whale has a remarkable song that sounds very mechanical and which must have caused great problems for the military when they first started to listen for submarines during the cold war. N.B. This sound clip is 60 seconds (626 KB) in length and may take a little time to download. A 5 second (56KB)version is also available.

General Ecology:

The minke is the smallest of the baleen (filter-feeding) whales and is found throughout the world's oceans, from the Arctic to the Antarctic. The minke is the whale most likely to be seen from the shore in the U.K. and Ireland, especially in Scotland, the Northern Isles and Western Ireland. It is rare in the Southern North Sea and Channel region.

Most of the baleen whales undergo seasonal migrations and, in many cases, these are over vast distances. The minke whale is unusual in apparently not conforming to this pattern, although they seem to move further away from the shore in the autumn, perhaps for breeding purposes. They also appear to be more solitary than other baleens and are usually seen singly or in pairs, although larger groups can gather. Some individuals have been closely monitored and remain within certain areas or "home ranges".

Minke whales are very adaptable and eat a wide range of fish and squid, as well as krill and other plankton. They feed in a variety of different ways, depending on the prey concerned and often trap shoals of fish against the water surface. Births occur in mid-winter, after a pregnancy of ten months. The new born calf is only about 2.6m long. It stays with its mother for about two years and reaches sexual maturity at about seven. The natural life span of minke whales is some fifty years.

Conservation:

The story of this whale's name illustrates its blighted history. Minke was an 18th-century Norwegian whaler, infamous for regularly breaking the rules concerning the sizes (and therefore species) of whales that he was permitted at that time to hunt. Soon all the small whales became known as "Minke's whales". Eventually, it was formally adopted as the name for this small species.

In fact, because they are such a small whale, the whaling industry generally ignored the minkes until quite recently. As the larger whales became more scarce (and gained protected status), so minke whales became more economically attractive. In the North Atlantic, from the 1920s, whaling for this species has been conducted along the coast of Norway. This expanded, just before World War Two, to Spritsbergen, Shetland and the Faroe Islands and, more recently, the Barents Sea and Iceland. When whale populations dwindled in the late 1940s, the International Whaling Commission (IWC) was established to manage whale stocks. The IWC announced how many whales could be taken in any year, however, populations continued to decline. In 1985/6 a worldwide moratorium on whaling was put in place, banning all whaling. Norway, however, "took out a reservation", meaning that they could continue by IWC rules to legally hunt North Atlantic minke whales and, in 1993 and 1994, they killed several hundred. This has caused great dismay in other countries, including the U.K., who have officially objected to this hunt. In UK waters it is illegal to intentionally kill, injure, capture or harass any species of whale or dolphin. However, there is little in international law that can be done about hunting, except control of exports which is covered by CITES (the Convention for International Trade in Endangered Species). This is important because the main consumers of whale meat are still the Japanese and, if Norway could legally export whale meat to Japan, this might further promote whaling. In 1993 a shipment of whale meat, labelled as "shrimp", was discovered at Oslo airport in Norway, on route to Asia.

Like other cetaceans, minke whales are also threatened by degradation of their habitat. This may be caused by depletion of their prey, perhaps resulting from over-fishing, and pollution and global climatic changes. Climatic change could, for example, affect ocean currents and therefore the locality and abundance of the whales' prey. An unknown number of minke whales also become entangled in fishing nets each year. The significance of these threats is only poorly known.

Frequent Questions:

Is hunting whales cruel?
Minke whales are hunted using an explosive harpoon. These replaced the "cold" (non explosive) harpoons because they killed the animals more quickly. However, the whales may still take a considerable length of time to die and there is widespread agreement, especially when it is compared to methods used to kill farm animals, that whaling is inhumane.

Is the minke whale population of the North Atlantic large enough to support a limited hunt?
Some of the fiercest battles at the IWC have been fought in recent years about the size of this population. Norway bases it's own quota on population estimates made by Norwegian scientists and these have been questioned. At what population size a whale population can actually be "sustainably harvested", if at all, is also a point of debate, especially noting the present lack of understanding of other threats to these animals. Another consideration is whether or not whaling out on the high seas can actually be properly controlled.

Further Information:

All available from The Mammal Society.

 

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