Common minke whale (Balaenoptera acutorostrata)
The minke whale is the most numerous of the rorqual whales in Norwegian waters, with the Northeast Atlantic stock numbering well over 100,000 animals. The minke whale is the smallest of the rorqual whales. It has the same general shape and colour as the larger members of this group, being quite sleek and streamlined in build, dark grey or black dorsally and lighter ventrally.
The minke whale is the smallest of the rorqual whales. It has the same general shape and colour as the larger members of this group, being quite sleek and streamlined in build, dark grey or black dorsally and lighter ventrally. In the North Atlantic minke whales can reach a length of 10 metres long, with females being slightly larger than males; they have a distinct white patch on their small pectoral (front) fins. The minke whale has an extremely narrow, pointed rostrum and a distinct head ridge. The dorsal fin is sickle-shaped and relatively tall compared to the size of the whale and it occurs quite far forward on the last 1/3rd of the body. Like all rorquals minke whales have prominent grooves on their throat region that extend from the chin back under the belly to approximately the midline. Minke whales normally take a short series of breaths when they are on the surface between dives. They do not show their flukes (tails) when they leave the surface and their blow tends to be diffuse and not very tall (max two metres). Calves are approximately 2.5 m long when they are born.
Minke whales are very broadly distributed in both northern and southern oceans. The species of minke whale that lives in the North Atlantic spends the winter months at the southern end of its range somewhere between the Straits of Gibraltar in the east and the Caribbean in the west (their winter distribution and behaviour is very poorly documented). They migrate northward in the spring reaching as far west as Baffin Bay in the Canadian Arctic and Svalbard in the east. In Svalbard, they are seen throughout the spring and summer, primarily on the west and north coasts of Spitsbergen. Remarkably, a Southern Ocean minke whale, as well as a hybrid between a North Atlantic and a Southern Ocean individual (which as classified as separate species) have been recently taken in the Norwegian harvest. These new genetic findings challenge the traditional wisdom, which was that the populations did not cross the equator from their respective hemispheres.
The minke whale is the most numerous of the rorqual whales in Norwegian waters, with the Northeast Atlantic stock numbering well over 100,000 animals. They are seen regularly along the coasts and deep into the fjords of Svalbard. Minke whales are usually solitary, although two or three individuals travelling together is not an uncommon sight. Clusters of animals have been documented at high latitudes but it is not known if this clustering is caused by concentration of prey or if it is socially facilitated. Males and females and their calves tend not to be found in the same areas; both age and sex segregation appears to take place. Almost all of the animals harvested around Svalbard are females. Minke whales surface only briefly for one or two breaths when they are travelling, so they can be overlooked easily, but when they are feeding they often surface repeatedly in an area or circle just below the surface and hence are easier to spot. Breaching has been observed in this species, but is not routine. Some minke whales approach boats readily and are very curious. A variety of sounds have been recorded from minke whales, including grunts, thumps and descending frequency sweeps, but they are not a particularly vocal species. North Atlantic minke whales feed on a variety of small fishes, including sand eels, capelin, mackerel, sprat and herring, as well as smaller food items such as euphausiids and larger fishes including salmon, cod, coal fish, whiting haddock and other species. Their diet varies considerably by season and location as well as from year to year. They feed in a manner similar to the other baleen whales (see Bowhead whales). Killer whales are known to hunt minke whales.
Life History & Reproduction
In the North Atlantic, mating occurs from October through until March. Gestation is approximately 10 months. Calves are born on the wintering grounds and stay with their mothers for four to five months. Sexual maturity is reached at approximately seven years of age in females, and perhaps a year earlier in males. Forvaltningsstatus og overvåkning
Status and monitoring
Minke whales have been hunted since the middle ages during their coastal migrations. Fishermen with primitive gear could trap the whales inside bays and fjords and then kill them with arrows. During the early periods of intense commercial whaling minke whales were largely ignored because of their small size but today they are the only large whale species that is commercially harvested. In Norway, including in Svalbard waters, minke whales are harvested on a quota-system, well within sustainable harvesting limits.
MOSJ indicators (Environmental Monitoring of Svalbard and Jan Mayen):
Awaiting results from MOSJ…