Blue Whales

By Brenden Napier

What is the Blue Whale?

The blue whale, or Balaenoptera musculus, is an enormous marine mammal in the baleen whale family. It feeds strictly on a small marine invertebrate called krill which it filters out of the water by the thousands using its filtering system called a baleen. These whales can reach up to 33 meters long and weigh over 150,000 kilograms, the length equivalent to a traditional basketball court and the weight equivalent of well over 2,000 people. Blue whales are identified by their large slender shape, often double that of humpback whales, and their splotchy grey markings that often look blue through the water. Three subspecies have been identified located in the northern hemisphere, antarctic, and Indian ocean.

Where do they reside and how does their location change?

Three geographic populations have been identified in the northern Atlantic, northern pacific, and southern hemisphere. The north Atlantic population which I will be focusing on ranges from the equator all the way up to the Gulf of St. Lawrence near Greenland. Blue whales are known for being a nomadic species that rarely stays in the same vicinity for more than 10 days. These animals can be seen in coastal waters, but the majority of these individuals tend to be found offshore. Their populations are distributed according to food availability and migratory patterns. They make pole movements during spring to capitalize on the plankton found in the poles and in the fall they tend to make tropic movements to limit expended energy while fasting.

When did blue whales become a listed endangered species and how are they listed?

Beginning in 1939, protective action began to take place starting with portions of the Southern Hemisphere. The International Convention for the Regulation of Whaling gave populations in the North Atlantic protection in 1955 and that protection was extended to the Antarctic in 1965 and the North Pacific in 1966. Iceland unfortunately did not formally recognize this protection until 1960. They are listed under the Endangered Species Act as well as the Marine Mammal Protection Act. The IUCN Red List recognizes the Antarctic population as endangered, the North Pacific Stock as low risk, and the North Atlantic Stock as vulnerable.

Why did the whales become endangered in the first place?

Different populations have slightly different reasons for being listed, however the dominant cause of endangerment by far is over hunting. They were hunted for their abundant source of baleen, blubber and meat. In the late 19th to mid 20th centuries, an estimated 11,000 individuals were killed due to whaling out of a then estimated 15,000 existing whales. Other somewhat negligible causes of endangerment consist of vessel strikes, whose injuries can be found in 9 percent of all whales seen in the St. Lawrence Gulf area, chemical pollution of habitat, as well as fishing gear entrapment.

How do we plan on recovering this species?

 Recovering these endangered populations of Blue Whales requires many things to happen. In order for the whales to be delisted or downlisted, first scientists must determine the stock structure of blue whale populations occurring in U.S. waters as well as around the world and estimate the size of these stocks. Then they must monitor trends in abundance by conducting annual independent photo-identification surveys. Scientists must identify essential habitat to the animals and protect this habitat. Once these preliminary things happen, scientists can begin to reduce or eliminate altogether human effects on the animals like ship collisions and fishing gear entanglement. Scientists' next priority is to maximize the information gathered from dead, stranded, and entangled blue whale. Then they must coordinate state, federal, and international efforts to implement recovery action and establish a criteria for deciding whether to delist or downlist blue whales.


What can you do?

To further protect these whales from extinction, advocates can take a stand to set a speed limit in shipping lanes that coincide with blue whale migratory paths. For example, 15 miles off the coast of Sri Lanka lies one of the worlds most bustling shipping lanes. We can advocate for a set speed limit of 10 knots to reduce the severity of major injuries that occur to blue whales.

Works Cited

"Graphic: How to skin a blue whale and prepare it for display in a museum." National Post. N.p., 

     n.d. Web. 2 Dec. 2015. <http://news.nationalpost.com/news/canada/ 

     graphic-how-to-skin-a-blue-whale-and-prepare-it-for-display-in-a-museum>. 

"Hunting Blue Whales." Blue Whale Endangered. N.p., n.d. Web. 2 Dec. 2015. 
     <http://endangeredbluewhale.blogspot.com/2012/12/human-impacts-history-of-man-and-blue.htm       l>. 
National Geographic Article About Whale Conservation. National Geographic Kids. N.p., n.d. Web.        2 Dec. 2015. <http://kids.nationalgeographic.com/content/dam/kids/photos/animals/Mammals/A-       G/blue-whale-map.GIF>.