WATER INSTITUTE SCIENTISTS HELP REPORT

ON THE STATE OF THE LAKES

By Casey Twanow

 

MILWAUKEE - Over 300 Great Lakes experts from the U.S. and Canada met November 1-3 in Milwaukee at the State of the Lakes Ecosystem Conference (SOLEC). The conference is held every second year as part of the binational Great Lakes Water Quality Agreement (GLWQA), to update resource managers and the general public on the health of the Great Lakes.

At the conference, scientists from both countries report on the status and trends in the Great Lakes in categories like contamination, aquatic habitats, and invasive species. Reports are based on analysis of compiled data and published papers from university and government sources. Tim Eder, the Great Lakes Commission’s executive director, called the research presented at SOLEC “the best science in the world on the health and conditions of the Great Lakes.” Several scientists from UWM’s Great Lakes WATER Institute participated in this year’s conference.

Harvey Bootsma reported on nutrients in the lakes, including nitrogen and phosphorus, which fertilize algae growth. Rebecca Klaper presented information on newly recognized water contaminants such as pharmaceuticals and personal care products. Sandra McLellan joined a panel discussing Great Lakes beach issues such as monitoring, management and public education.

Bootsma reported that total phosphorus loads flowing to the Great Lakes meet water quality goals, except in Lake Erie. High phosphorus levels in some nearshore waters, however, likely contribute to excess growth of the nuisance algae Cladophora in Lakes Michigan, Huron, Erie and Ontario. When Cladophora washes ashore and rots, it not only affects beach aesthetics, but can be a health and safety risk.

 

Industrial activities, wastewater, and agricultural runoff add phosphorus to the lakes. Long-term management is complicated by phosphorus accumulated in agricultural soils and washed into streams and lakes over time. Bootsma said this is “a hurdle we’re going to have to consider for decades, if not centuries, to come.”

 

Based on current trends, Bootsma said chlorides and nitrogen in the Great Lakes will continue to increase. Industrial activities and runoff carrying road salts and fertilizers add to their levels in the lakes. Calcium levels in the Great Lakes, which affect clarity, have declined due to uptake by invasive mussels. The impacts of changing levels of chlorides, nitrogen and calcium on the lakes’ ecosystem are unknown.

Klaper reported research on the effects of prescription drugs and antibiotics (disposed of down the drain and excreted), and fragrances and chemicals in consumer products that enter our wastewater and streams. Scientists have recently begun to study the effects of these pollutants on aquatic life, and sampling fish, mussels and sediments for accumulation of many compounds is underway.

In Milwaukee’s harbor, Klaper found that water samples from near wastewater treatment outfalls contained common painkillers (acetaminophen and hydrocodone) and antibiotics (amoxicillin) in measurable levels. She has exposed invertebrates and fish to anti-depressants and lipid regulators, and said “We’ve found that these drugs may have unintended effects in aquatic organisms,” including affecting heart rate and reproduction.

Further research and funding is needed to understand the ecosystem effects of these emerging contaminants, and new management techniques may be required to control them. One preventative measure is collecting unused and expired medications for proper disposal, instead of flushing them down the sink or toilet. Klaper said that a recent Milwaukee collection day yielded 16 30-gallon drums of unused medicines.

  

Overall, the reports of university and government scientists created a discouraging picture. Some aspects of Great Lakes health are good, such as drinking water quality, or improving, such as contamination in sport fish. Most measures of ecosystem health vary across different lakes and watershed areas, with Lake Superior supporting the healthiest ecosystem. Many conditions have shown little change in recent years, such as beach closures, while some are deteriorating, such as declining populations of small prey fish, and worsening impacts of invasive species.

For Lake Michigan, specific concerns included declining populations of diporeia, a shrimp-like bottom-dweller that is a major food source for many native fish. Carrie Lohse-Hanson from Minnesota’s Pollution Control Agency characterized the lake’s diporeia populations as “in poor shape and getting worse.” This decline, observed in all Great Lakes except Lake Superior, has not been explained but is correlated with the growing range of invasive quagga mussels. In discussing invasive species, Judy Beck of the Environmental Protection Agency described Lake Michigan as a “worst-case scenario” because of the dual threats of invasive species from overseas in contaminated ballast water and Asian carp from the Mississippi River system.

A Lake Michigan session at SOLEC provided updates on clean-up and restoration efforts in the lake’s 10 Areas of Concern identified by the GLWQA. Wisconsin’s Areas of Concern include the Milwaukee Estuary and the Sheboygan River. In many Areas of Concern, sediments contaminated by past industry and development have been removed to improve water quality. The session also reviewed the Lakewide Management Plan for Lake Michigan. The GLWQA calls for development of such a plan for each lake to summarize progress towards water quality goals.

SOLEC reports are available online at http://www.epa.gov/solec, and reports on Lake Michigan’s Areas of Concern and Lakewide Management Plan are available at www.epa.gov/glnpo/michigan.html.

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