The state of Lake Erie is called “poor and unchanging” in a new report jointly sponsored by the US and Canadian governments.
The lake “supports a productive cowfish fishery, but elevated nutrient concentrations and algal blooms are persistent problems,” according to a page summarizing the findings. Lake Erie is the only one of the five Great Lakes listed as impoverished. Lakes Huron and Superior are rated as “okay” while lakes Michigan and Ontario are called “fair”.
The report rates each lake in nine areas: drinking water, beaches, fish consumption, toxic chemicals, habitats and species, nutrients and algae, invasive species, groundwater and watersheds, and climate trends.
There are very few problems in the Great Lakes with treated drinking water, the report states. Beaches are also stable, with safe swimming nearly all of the time—although in Lake Erie, the only lake rated fair and poor, U.S. beaches were safe for swimming 84 percent of the time during the 2018-19 monitoring period, compared to 94 % for US beaches as a whole.
Lake Erie’s groundwater is rated good. The accompanying map shows the waters flowing from Chautauqua County into the lake as good, although the rest of Western New York is only fair.
Fish consumption is “fair and improving”, with the report noting that many contaminants in fish fillets have declined dramatically in the Great Lakes over the past 40 to 50 years.
The biggest problems with Lake Erie appear in the other categories.
The lake is called poor in the nutrient and algae category, although this is mostly due to activity in the western and central basins of the lake. Harmful algal blooms are often formed by nutrient concentrations in the western basin.
As habitats and species, coastal wetlands are poor for fish and plants, fair for amphibians and birds. “Most of the wetlands in Lakes Erie and Ontario have degraded plant communities as a result of nutrient enrichment, sedimentation, invasive species, past water level regulation, or combinations of these factors.” according to the report.
As for the aquatic food web, things are looking up for trout, sturgeon and fish – their populations in Lake Erie are said to be improving, although only fish have “okay” overall current health status. The trout is called fair; sturgeon is poor as it is in any large lake. An increase in natural sturgeon spawning is reported, “although changes in lake sturgeon status will take a long time to manifest due to the longevity of the streak.”
There is bad news for the quality of phytoplankton at the bottom of the food chain. It is considered poor and deteriorating in Lake Erie “due to an increase in the abundance of harmful cyanobacteria.”
When it comes to invasive, non-native species, new introductions have been significantly less in recent years, but the impact of those already introduced gets a poor rating in every lake.
The level of toxic chemicals in the water and fish of Lake Erie is called “just and unchangeable”, while toxicity is fair and improves in the sediment. One graph shows how concentrations of one toxic chemical group, polycholine biphenyls, have gradually declined near Sturgeon Point in southern Erie County since the early 1990s.
In the watershed category, Lake Erie scored poorly for forest cover, land cover, hardened shorelines, and tributary water quality. Most of the watershed is in southeastern Michigan and northern Ohio, with significant population, agricultural, and heavy industrial loads.
The Lake Erie basin has only 21% of its natural land cover, compared to 97% of relatively remote Lake Superior.
In terms of climate trends, Lake Erie precipitation, water levels, and surface water temperatures are generally increasing while winter ice cover is decreasing.