UNITED NATIONS — Actress and activist Jane Fonda is campaigning for a treaty to save marine creatures that are hunted for food including sharks, swordfish, octopus and tuna, saying they feel joy, feel sadness when they lose their offspring, and “are our brethren in the ocean.”

A day after talks resumed at U.N. headquarters to forge a long-awaited and elusive treaty to safeguard the world’s marine biodiversity, the 85-year-old Oscar winner told a news conference Tuesday that these marine creatures “play with us and they feel emotions — and how dare we so lack humility that we will risk killing them off for money and for food.”

For almost four years, Fonda said, she has been working with Greenpeace, and she came to New York to deliver 5.5 million signatures from people in 157 countries demanding a strong Global Ocean Treaty to Rena Lee, president of the U.N. negotiations. A key aim for the treaty is to turn 30% of the world’s oceans into marine sanctuaries by 2030 where fishing is banned.

Growing up in Santa Monica, California, Fonda said she loves the ocean and was at the beach every day that it was warm enough. And she said she has been scuba diving at the Great Barrier Reef in Australia, in the Galapagos in Ecuador, in the Caribbean, and elsewhere in the world.

“I’ve swum with some of the most magnificent creatures, and I know that they may very well be more intelligent than me,” Fonda said. “And I love them, and I think that we should all understand that we’re talking about saving the last great wild animals that are hunted for food.”

Fonda said the world can’t survive without healthy oceans, which scientists say provide 50% of the oxygen we breathe. But the oceans are subject to overfishing and pollution, including pieces of plastic that fish eat, she said.

The heating of the ocean as a result of climate change is also killing kelp beds that many marine creatures depend on to live, she said, and the leaching of fertilizer from industrial farms “is causing massive and expanding dead zones in the ocean.”

“The ocean is our ally,” Fonda said. “Let us love and respect it.”

Hervé Berville, France’s secretary of state for the sea who sat next to Fonda, said he believes “we have the political momentum” during negotiations that end on March 3 to overcome the remaining challenges and reach agreement on a treaty protecting 30% of the ocean by 2030.

Fonda warned that time is running out.

“Even dogs don’t poop in their kennel, because they know that the kennel provides security and a home for them,” she said. “We’re pooping in our kennel.”

Humans are destroying things they don’t understand, Fonda said.

“Why the treaty is important is it will force us to behave right, and to save this great ally that we have called the ocean — the one ocean on this blue planet that can save us,” she said. “There’s a lot at stake.”