Sei Whales

The Sei Whale (pronounced "Say") is an irregular visitor to our area. I say "irregular" because we may go years without seeing one on one of our whale watches, then dozens may move into the Gloucester area seemingly overnight. As you might guess, prey distribution probably has a lot to do with these unpredictable shift in Sei Whale abundance. In the Summer of 1985, for example, Sei Whales were probable the most common whale species in our area for much of the year. The Summer of 2005 also so a good number of Sei Whales in the Jeffrey's Ledge and southern Stellwagen Bank region in July and August.

Identification of a Sei Whale is difficult for whale watchers not familiar with this species. Sei Whales look superficially similar to Finback Whales on they are smaller, darker, and lack the asymmetrical coloration of the Fin Whale. Upon close examination, Sei Whales are often marked with lighter "spots" which are actually scars from Cookie-cutter Sharks which seem to delight in taking small bites out of the flanks of these whales (look closely at the photograph above and you can see a few of these scars). The dorsal fin of a Sei Whale is also proportionally larger and more erect than that of most Finback Whales... I like to describe Sei Whales as looking like an over-turned surf boards. Whalers used to identify this species by watching the way in which they swam... Sei Whales change direction very erratically when feeding. The preferred food item of the Sei Whale is a small schooling fish such as Herring and Pollock. In fact, "Sei" is an adaptation of the Norwegian word for Pollack ("Seje") and these whales were called "Seje" or "Pollock Whales" because large numbers of Seje/Sei Whales showed up along the Norwegian coast at the same time schools of Pollack arrived.

Sei Whale are a widely distributed species (they are found in all major oceans) but little is known of their biology or habits.