Sea Lions

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Context

• The Channel Islands Marine & Wildlife Institute reported 1,000 sightings of sick and dead marine mammals from June 8 through 14.
• They were found dead and sick along the coast of Southern California.
• Many sick sea lion and new born pups are rescued from the beach and taken care at marine mammal care centres.

Other Details

• Outbreak of algae bloom, also known as red tide, is being blamed for causing sickness and death to sea lions and dolphins.
• As per California wildlife experts there is a sudden surge in animals falling ill to a neurotoxin.
• Small fish consume the toxin and pass it up the food chain.

Symptoms of Sickness

• Swaying their heads back and forth.
• Foam at the mouth.
• Experiencing seizures.
• Lying listlessly in the surf.

California Sea Lions

• The scientific name of California sealions is Zalophus californianus.
• These animals belong to the family Otariidae.
• This coastal eared seal is one of six species of sea lions and is native to western North America.

Features

• Large and playful eyes.
• Pale to dark brown in appearance but seems black when wet.
• A thick neck.
• They can reach a maximum length of about 2.5 metres.
• Weight could be as heavy as 1200 pounds.
• In captivity it can live more than 30 years.

Significance

• Important for Marine diversity.
• Tourist attractions and hence can contribute to support economy.
• Sea lions are considered a sentinel species, it means they are the animals that can help identify environmental risks to humans.

Diet and Habitat

• They feed on a wide variety of seafood, mainly squid and fish, and sometimes clams.
• They could be found along the western coast and islands of North America, from southeast Alaska to central Mexico.
• It is mostly a coastal animal that frequently comes out from the water when swimming.
• Highly trainable and are generally friendly to humans.

Threats

• Algae Bloom
• Introduced species, such as dogs, carry diseases that can spread to sea lions.
• Climate change effect on ocean currents makes their survival difficult by severely affecting the food (fish) availability.
• Their by-catch in fisheries could be another threat for their survival.

Algae Bloom The algae is a natural phenomenon that causes the production of a neurotoxin called domoic acid. However a harmful algal bloom (HAB) occurs when toxin-producing algae grow excessively in a body of water. Reasons of Algal bloom Human induced climate change Release of excess of nitrates washed out to sea. Discharge of other polluting substance and industrial affluent to oceans.

Conservation Status

• California sea lion are considered as Least Concern as per IUCN Red list.
• It is protected by the federal Marine Mammal Protection Act (MMPA), 1972.

PRACTICE QUESTION Consider the following statements about Californian Sea Lion: 1. It is considered as one of the most vulnerable types of sea lions. 2. This Species is friendly to humans and highly trainable. Which of the statements given above is/are correct? A. 1 only B. 2 only C. Both 1 and 2 D. Neither 1 nor 2 Answer: (B)

https://www.thehindu.com/sci-tech/energy-and-environment/sick-sea-lions-washing-ashore-in-california-due-to-algae-bloom/article67018344.ece