Two reports published in December call attention to the loss of critical seagrasses and phytoplankton in saltwater ecosystems worldwide.

Frederick Short, research professor of natural resources and marine science at the University of New Hampshire, says seagrass ecosystems are at a “global crisis” in an article he co-authored in the December issue of Bioscience, the journal of the American Institute of Biological Sciences.

The article cites the critical role seagrasses—underwater plants that live fully immersed in the sea—play in coastal systems and how coastal development, population growth and the resulting increase of nutrient and sediment pollution have contributed to large-scale losses worldwide.

“Seagrasses in New England are declining in most areas due to human impacts, from eutrophication and upland development, mainly,” said Short in press release last week. “North of Cape Cod, we estimate we’ve lost 20 percent of seagrass from historical distribution levels; south of Cape Cod, where the shoreline is more developed, we’ve lost 65 percent.”

Short is part of a team calling for a targeted conservation effort to preserve seagrasses and their ecological services to the world’s ecosystems, according to a press release from UNH.

“Seagrasses are the coal mine canaries of coastal ecosystems,” said co-author Dr. William Dennison, of the University of Maryland Center for Environmental Science. “The fate of seagrasses can provide resource managers advance signs of deteriorating ecological conditions caused by poor water quality and pollution.”

While recent studies rank seagrass as one of the most valuable habitats in coastal systems, media coverage of other habitats—including salt marshes, mangroves and coral reefs—receive 3 to 100-fold more media attention than seagrass systems.

Seagrasses influence the physical, chemical and biological environments of coastal waters, and can provide critical habitat for aquatic life, alter water flow and mitigate the impact of nutrient and sediment pollution, according to the press release.

An article in the journal Nature published Dec. 7, says the oceans have lost some of their green tint over the past decade, most likely because the plants that produce that shade are reproducing more slowly as the oceans are warming. The result is a reduction in ocean life and an increase in atmospheric carbon dioxide, say scientists at the University of California, Santa Barbara.

“We show on a global scale that the growth of these plants, called phytoplankton, is strongly tied to changes in the warming of the ocean,” said David Siegel, co-author and professor of marine science in the Department of Geography at the University of California, Santa Barbara, in the article.

“Phytoplankton are responsible for about the same amount of photosynthesis each year as all the plants on land combined,” according to the article.

If the microscopic plants grow even slower in the warmer oceans of the future, as predicted, there will be less food available to fish, birds and other creatures in the food change. In addition, less carbon dioxide will be taken up by these oceanic plants, allowing it to accumulate more rapidly in the atmosphere, which would in turn accelerate warming.