Minke WhalesBalaenoptera acutorostrata
The Minke whale is the smallest of the rorquals. The male of the species can grow to a length of 9.8m (32ft) and the female larger at 11m (36ft) and weigh 10 tonnes. Populations in the Southern hemisphere on the average are slightly larger than other areas. Some animals are inquisitive and approach quite closely, but in most cases it is unusual to get a clear view. The Minke can be confused with the Sei, Bryde's, Fin or Northern Bottlenose whale, however, the dive sequence is distinctively different, the head is unscarred and it's mouthline is relatively straight.
The Minke whale has a slender streamlined body with a pointed head and often inconspicuous blow. The body is dark grey to black on the back, lightening to white on the belly and undersides of the flippers. There are often areas of light grey on the flanks, one just above and behind the flippers and the other behind the head. Individuals in the Northern hemisphere have a diagonal white band on the upper surface of each flipper. The head of the whale has an overall triangular shape, a single sharp longitudinal ridge along the top and forward of the blowhole and a narrow pointed snout. It has twin blowholes typical of all baleen whales.
Baleen plates are found on each side of the upper jaw. The plates numbering between 230 to 360 are short 20-30cm (8-12in) in length and about 12cm (5in) in width. The colour of the plates vary from region to region; in the North Atlantic, it tends to be creamy white; in the North Pacific, it is usually creamy yellow; and in the Southern hemisphere it is creamy white at the front and dark grey at the back. Atlantic Minkes usually have more plates than the Pacific Minkes.
Minke whales can be found virtually worldwide, but are less common in the tropics than in cooler waters. The Minke often enters estuaries, bays and inlets and during summer may feed around headlands and small islands. Most, seasonally migrating from polar feeding grounds to warm temperate to tropical breeding grounds although there appears to be some groups resident year-round. There are three geographically isolated populations recognized, in the North Pacific, in the North Atlantic and in the Southern Hemisphere.
The Minke is the smallest of the seven great whales. It's size made it uneconomical to harvest commercially while the larger whales were in abundance. The species became protected with the declaration of the 'Moratorium' on whaling by the International Whaling Commission in 1986. Norway and Japan are two countries that argue since the Minke is abundant it is not endangered and therefore they are harvesting (killing), albeit in small numbers, this species on a regular basis. Although it's numbers are not endangered it is on the endangered list as a threatened species, and is protected (since 1986) worldwide by international law.
This species is attracted to ships and often approaches moving vessels. The Minke whale is a fast swimmer and can keep pace with a ship travelling at 24-30 knots per hour. A Minke may suddenly appear alongside without warning but it is unlikely to bow-ride.
The blow is low and indistinct, often invisible without a dark background. This is possibly because theystart to exhale while still underwater. The breathing sequence consists of 5-8 blows at intervals of less than a minute, followed by a deep dive that can last up to 20 minutes. It normally takes only 1 or 2 breaths between dives when travelling. The fin always appears with the blow and the tailstock is arched high into the air before sounding. The flukes are never shown unless the whale breaches.
Minkes observed breaching usually leave the water at 45° and re-enter without twisting or turning their bodies. Most of the body may leave the water with the initial surge and the entire dorsal fin is often visible. The back can be arched allowing for a clean dolphin like re-entry or held straight causing a tremendous splash as it lands on its stomach.
The Minke Whale is the smallest Rorqual and has a central ridge on top of a flat head. The fin is in thelast third of the back, is tall and erect and relative to body size, is the tallest of all baleen whales. The flipper is pointed and measures about 12% of body length. The neck is creased by 60-70 grooves running all the way back to the navel. The colour is bluish dark grey above and lighter below. The distinctive marking is a bright white patch or diagonal band across the middle of the upper surface of the flipper, the size and shape of which shows a wide variation.
The whale favours shallow water, estuaries and tidal streams in warmer water, venturing into inland seas and rivers more often than other baleen whales. It sometimes gets trapped inside small pockets of open water within pack-ice.