The world's oceans are ground zero for climate change. They cover more than 70% of the Earth's surface and contain 97% of the planet's water. A weather phenomenon known as the "blob" is impacting the world's largest ocean, the Pacific.

The creatures at a San Diego rescue center are getting a second chance at life. SeaWorld's Jody Westberg expects to release sea lions early next year and is dreading what could happen next.

"The animals that are the most heart wrenching for us to rescue are the animals that the only reason we're rescuing them is because of something caused by human impact," Westberg said.

They could soon be victims of what's known as the "blob," a sci-fi sounding term for ocean heatwaves made worse by climate change. The blob is responsible for toxic algae blooms that kill plankton, a key food source for marine life.

The "blob" is responsible for toxic algae blooms that kill plankton, a key food source for marine life. CBS News

Oceanographer Melissa Carter measures water temperatures and algae levels. She's concerned that the massive blob that formed in the Pacific in 2015 is now reforming.

A side-by-side comparison of Pacific temperatures then and now show striking similarities. Some areas are 12 degrees above normal. Another blob could decimate the shellfish industry, as it did in 2015.

While the fish at Seattle's Pike Place Market are considered safe for now, a Washington state lab is conducting regular tests by blending them and measuring for toxins.



"The ocean is critical. It's the most critical piece of giving us a moderate climate on Earth," Carter said.

Experts warn marine life could be harmed by rising ocean temperatures. CBS News

But once again in the Pacific, what was moderate is now extreme, leaving an uncertain future for animals.

"They're really letting us know what's going on with the ocean's health. What's impacting them is eventually gonna impact us," Westberg said.

In our "Eye on Earth" series, we're looking ahead to a landmark United Nations Climate Action Summit next week. CBS News is the only broadcast network participating in the "Covering Climate Now" Project, in partnership with 250 other news outlets. We're highlighting the health of our planet with our own original reporting.