The Minke Whale

(Balaenoptera acutorostrata)

Length: 8-10 metres (26-33 feet) Lifespan about 50 years.

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 they start 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 the last 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.