IKAN Guide to Whales

Sei Whale - Balaenoptera borealis

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The adult sei whale measures between 12 - 16 meters in length and can weigh between 20 - 30 tons.

The sei whale is distributed globally but is found mainly in offshore temperate waters. They belong to the family Balaenopteridae, possessing plates of baleen that filters small crustaceans, fish as well as small mollusks such as squid and octopus. The sei whale is capable of swimming very fast, but it generally stays close to the surface and can be followed by the so-called "fluke prints" or swirls of water created when the whale beats it's tail. Their pod size is usually about 2 - 5 individuals but it would depend on food availability. Whalers heavily hunted the sei, particularly during the 1960s. As a result of this the population was severely depleted and, despite the whaling moratorium imposed by the International Whaling Commission in 1986, the sei still needs a long time to recover. Various threats still linger which may effect the recovery of the sei population. Among these threats would be pollution, fishing gear entanglement and collisions with boats, and recently, Japan started hunting 50 sei whales in the name of 'scientific research'.