Seiv The Whales (Sei Whale): Taylor Chase

Sei Whale (Balaenoptera borealis)

Ecology

As the third largest member of the Balaenopteridae family the Sei Whale can grow as large as 18 meters in length. Similar in physiology to the Humpback Whale, the Sei Whale is grey in color with a white region on the underside of their bodies. The Sei Whale is usually solitary or in small groups, without a well defined social structure. The Sei Whale, like other balaenopterids, have bristle like baleen plates instead of teeth and use them to filter massive amounts of water in order to feed on the small zooplankton. Balaenoptera borealis, is found in every ocean and migrate long distances. They are found in the high-latitude areas during the summer time, and migrate to low-latitude areas during the breeding season. Sei Whales reach sexual maturity between 5 and 15 years of age, after a 12 month gestation period a calf is born. The calves, on average, are 4.4 metes long and feed with their mother until they reach a length of nearly 9 meters.

Classification and Recovery

Currently, the Sei Whale is listed as an endangered species under the Endangered Species Act of 1973. Populations of Sei Whales where greatly reduced in the 1950s through the 1970s as a result of commercial whaling. By-catch is another cause of Sei Whale death, fishery related death due to the use of drift gillnet and other boating accidents may cause a significant number of whales to be killed. Current population statuses are unknown, and therefor the recovery plan is to provide a research strategy to obtain population trends, abundance, and structure. The current recovery plan also seeks to identify factors that limit the Sei Whales recovery. 

The adaptive management strategy has been divided into three parts:

1. Continued international regulation of whaling

2. Determine population size, trends, and structure

3. Continued stranding response and associated data collection.

Sources 

Final Recovery Plan for the Sei Whale (Balaenoptera Borealis). Silver Spring, Md.: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Office of Protected Resources, 2011. Print.

S.L. Perry; D.P. DeMaster; G.K. Silber (1999). "Special Issue: The Great Whales: History and Status of Six Species Listed as Endangered Under the U.S. Endangered Species Act of 1973".Marine Fisheries Review 61 (1): 52–58.

Picture Credit: Google, National Geographic