The blob is a term used to refer to a large mass of algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 that was first spotted floating in the Chukchi Sea

Chukchi Sea

Chukchi Sea is a marginal sea of the Arctic Ocean. It is bounded on the west by the De Long Strait, off Wrangel Island, and in the east by Point Barrow, Alaska, beyond which lies the Beaufort Sea. The Bering Strait forms its southernmost limit and connects it to the Bering Sea and the Pacific...

 between the Alaskan

Alaska

Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

 cities of Wainwright

Wainwright, Alaska

Wainwright or Ulguniq or Kuuk is a city in North Slope Borough, Alaska, United States. At the 2000 census the population was 546, making it the third largest city in the North Slope Borough. The community was named after Wainwright Lagoon, which in turn was named an officer under Capt. F.W....

 and Barrow

Barrow, Alaska

Barrow is the largest city of the North Slope Borough in the U.S. state of Alaska. It is one of the northernmost cities in the world and is the northernmost city in the United States of America, with nearby Point Barrow being the nation's northernmost point. Barrow's population was 4,212 at the...

in July 2009. A notable feature of the mass is its length of at least 12 miles (19.3 km). The algae is colored black, which is considered to be unusual. Early examiners of the algae were unable to determine its species.