Fish waste appears to play an important role in regulating the oceans’ delicate chemistry, helping to balance acid levels that can harm sea life, according to research published today in Science.

The news comes at a time of increasing concern about the effects that humans’ carbon dioxide emissions are having on the world’s oceans. Since the beginning of the Industrial Revolution, the oceans have absorbed about a third of human-caused CO2 emissions. That has resulted in water 30 percent more acidic than it was before factories, cars, planes and other fossil-fuel burning machines became widespread.

And that’s a problem for shellfish, corals and marine animals that grow hard shells made of a chalky, alkaline mineral called calcium carbonate.

An economic stimulus plan released by House Democrats yesterday would pump more than $1 billion into climate science at federal agencies, including long-ailing environmental satellite programs.

The $825 billion proposal would also provide tens of billions of dollars for the programs to encourage energy efficiency and develop renewable and alternative fuels and technology to capture and sequester carbon dioxide emitted by power plants.

The House bill’s strong emphasis on science agencies is unusual for a supplemental spending bill, let alone one aimed at propping up the sagging economy, experts said.

An environmental group said yesterday that it will sue the federal government to gain protection for the ashy storm-petrel, a California shorebird whose habitat is threatened by climate change.

The Center for Biological Diversity filed formal notice of its intent to sue the U.S. Fish and Wildlife Service, which missed an October deadline to decide whether to grant endangered or threatened status to the petrels.

The agency agreed to consider protecting the birds under the Endangered Species Act in May,