Quantcast

Great Lakes Ecosystems Threatened by Food Scarcity

Declines of the food resources that feed lake organisms are likely causing dramatic changes in the Great Lakes, according to a new U.S. Geological Survey (USGS) study.

USGS scientists and partners found that since 1998, water clarity has been increasing in a majority of the Great Lakes, while phytoplankton (the microscopic water organisms that feed all other animals), native invertebrates and prey fish have been declining.

These food web changes fundamentally affect the ecosystem’s valuable resources and are likely caused by decreasing levels of lake nutrients, and by growing numbers of invasive species such as zebra and quagga mussels.

"These findings provide critical information to help decision-makers understand changes that are affecting the Great Lakes fishery that generates about $7 billion for the economy each year," said Suzette Kimball, acting director of the USGS. "The work is the result of a strong public-private collaboration and greatly contributes to managers' ability to deal effectively with the changes occurring in these unique and vast freshwater ecosystems so important to our nation."

The study found that inputs of phosphorus—the nutrient that limits phytoplankton growth—have declined in the Great Lakes since 1972, when the Great Lakes Water Quality Agreement was signed. The growing numbers of invasive species such as zebra and quagga mussels have caused phosphorus levels to decline further over the last decade in some lakes by filtering out phytoplankton and the nutrients therein. These decreases in nutrients have the potential to affect the smallest organisms up to the top predators: in Lake Huron, for example, plankton and fish appear to be controlled by declining nutrients or food.

"Our study provides a comprehensive ecological report card that highlights existing gaps in scientific understanding and monitoring of the complex Great Lakes ecosystems," said David "Bo" Bunnell, USGS scientist and lead author of the study. "Ideally, it will spur future research to more rigorously test some of the predictions born from our relatively simple analyses."

The Great Lakes provide valuable ecosystem services to the 30 million people that live within the watershed, but portions have been degraded since the industrial era. In 2010, the U.S. government initiated the Great Lakes Restoration Initiative, the largest investment in the Great Lakes in two decades, investing approximately $1 billion over the past four years.

USGS partners in this new study include the CSC information technology firm, U.S. Environmental Protection Agency, Ohio State UniversityUniversity of Wisconsin-Green BayMichigan State University, National Oceanic and Atmospheric Administration, Michigan Department of Natural Resources, University of Michigan, U.S. Fish and Wildlife Service and University of Illinois at Chicago.

The report is published in the journal BioScience.

Visit EcoWatch’s BIODIVERSITY and WATER pages for more related news on this topic.

EcoWatch Daily Newsletter

Justin Trudeau delivers remarks during an election rally in Markham, Ontario, Canada, on Sept. 15. Creative Touch Imaging Ltd. / NurPhoto via Getty Images

By Chloe Farand for Climate Home News

Canadians are voting on Monday in an election observers say will define the country's climate future.

Read More Show Less
Activists Greta Thunberg (2ndL), Iris Duquesne(C), and Alexandria Villaseñor (3rd R) attend a press conference where 16 children present their official human rights complaint on the climate crisis to the UN Committee on the Rights of the Child at the UNICEF Building on Sept. 23 in NYC. KENA BETANCUR / AFP / Getty Images

By Jessica Taft

Fifteen kids from a dozen countries, including Swedish activist Greta Thunberg, recently brought a formal complaint to the United Nations. They're arguing that climate change violates children's rights as guaranteed by the Convention on the Rights of the Child, a global agreement.

Read More Show Less
Sponsored
Cleanup costs for abandoned oil and gas wells once the producers have moved on could fall heavily on the public.
Susan Vineyard / iStock / Getty Images Plus

By Justin Mikulka

Increasingly, U.S. shale firms appear unable to pay back investors for the money borrowed to fuel the last decade of the fracking boom. In a similar vein, those companies also seem poised to stiff the public on cleanup costs for abandoned oil and gas wells once the producers have moved on.

Read More Show Less
Blue tarps given out by FEMA cover several roofs two years after Hurricane Maria affected the island in San Juan, Puerto Rico, Sept. 18. RICARDO ARDUENGO / AFP / Getty Images

Top officials at the Department of Housing and Urban Development confirmed to lawmakers last week that they knowingly — and illegally — stalled hurricane aid to Puerto Rico.

Read More Show Less
Actress Jane Fonda (C) and actor Sam Waterston (L) participate in a protest in front of the U.S. Capitol during a "Fire Drill Fridays" climate change protest and rally on Capitol Hill, Oct. 18. Mark Wilson / Getty Images News

It appears Jane Fonda is good for her word. The actress and political activist said she would hold demonstrations on Capitol Hill every Friday through January to demand action on the climate crisis. Sure enough, Fonda was arrested for demonstrating a second Friday in a row Oct. 18, according to The Hollywood Reporter. Only this time, her Grace and Frankie co-star Sam Waterston joined her.

Read More Show Less
Sponsored
Visitors look at the Aletsch glacier above Bettmeralp, in the Swiss Alps, on Oct. 1. The mighty Aletsch — the largest glacier in the Alps — could completely disappear by the end of this century if nothing is done to rein in climate change, a study showed on Sept. 12. FABRICE COFFRINI / AFP via Getty Images

Switzerland's two Green parties made historic gains in the country's parliamentary elections Sunday, according to projections based on preliminary results reported by The New York Times.

Read More Show Less
A mural in Richwood, West Virginia, a once booming Appalachia coal town, honors the community's history. Jeff Greenberg / Universal Images Group / Getty Images

By Jeff Turrentine

The coal industry is dying. But we can't allow the communities that have been dependent on coal to die along with it.

Read More Show Less
ThitareeSarmkasat / iStock / Getty Images

by Jillian Kubala, MS, RD

Every fruit lover has their go-to favorites. Bananas, apples, and melons are popular choices worldwide and can be purchased almost anywhere.

Read More Show Less