Group of rescued gray seals heads home after rehabilitation

John Yang:

Finally tonight, we go to New England, where a group of seals is making a splash.

John Yang (voice-over):

On a beach in Westerly, Rhode Island, onlookers watch as a gray seal emerges from a crate and heads toward the waters of the Atlantic Ocean, flopping along on its belly in an undulating motion known as galumphing.

Sarah Callan, Mystic Aquarium:

It's so important to protect the species because prior to the 1970s, the populations were almost completely decimated.

John Yang (voice-over):

Sarah Callan manages the animal rescue program at Connecticut's Mystic Aquarium. The released seal was one of six her team rescued during March and April from the waters near Block Island, Rhode Island. They had become ensnared in fishing gear and other debris.

Callan says sea litter, much of it plastic, is a growing threat to seals and other mammals around the globe. Each year, nearly 100,000 marine mammals are killed or injured after becoming ensnared in discarded plastic.

Sarah Callan:

We've had animals get entangled in frisbees that end up around their necks, so all sorts of everyday things. Animals can ingest the plastic as well, which poses many threats to them.

John Yang (voice-over):

Callan's team spent weeks nursing the rescued seals back to health, treating their severe infected wounds with antibiotics before releasing them. Researchers made sure they'd be able to track them.

Sarah Callan:

The seals that we released had a variety of tags on them, and those tags are going to give us really great real time data about the animal's location, how deep they're diving, and then how long they spend at each depth.

John Yang (voice-over):

Gray seals can dive up to 1,000ft for food and can hold their breath underwater for up to 90 minutes. And Callan says they play a big role in the health of their ecosystems.

Sarah Callan:

Seals help nourish the ocean, they spread nutrients around, and they're just such a vital part of the environment.

John Yang (voice-over):

In addition to marine pollution, habitat loss and climate change threaten their future. And Sarah Callan says her group and others like it will be around as long as seals and other marine animals need help.