Authorities recently gave out advisories regarding the high level of toxic mercury in Great Lakes fish. With the advisories came a recommendation to limit certain fish species consumption.Livnfresh is an advocate for keeping Lake Michigan and the Great lakes beautiful and clean for humans as well as the creatures that dwell beneath.
Side effects of Mercury
Mercury, a heavy, silver metal forms as a liquid at room temperature and is deadly to animals, especially to humans. The Environmental Protection Agency or EPA discovered that short-term exposure to mercury found in water can result in health hazards. Kidney damage can happen when exposed to mercury at levels beyond the contaminant level of 0.002 ppm. The toxic substance can also result to brain damage in children and hinder brain development in developing babies. Mercury can also attack the immune system and damage heart function in adults.
Since 1970 the mercury content found in Greta Lakes based fish continued to drop progressively. The reduction of mercury was the result of stricter Midwestern smokestacks regulations and the closure of coal-fired manufacturing plants. Also, technology provides massive benefit for pollution prevention.
Research scientist at the Environment and Climate Change Canada, Agnes Richards said, “We’ve been monitoring since the 1970s and the (mercury contamination) trends overall have been declining, as have been the emissions of mercury into the atmosphere and deposition into the lakes.”
Richards also added, “We decided to look at recent trends, from 2000 to 2015. What we found is, at some specific sites, trends have reversed.”
Reversal of the trend
In the past years, the trend started to change. Scientist found mercury level increasing in several Great Lakes fish like walleye and lake trout. Another peculiar case in the toxic mercury reports shows that not all fishes are affected. Researchers are still conducting more studies to find out the reason for the incidence.
Joseph Bohr, the aquatic biologist for the Michigan Department of Environmental Quality’s Water Resources Division claimed that mercury level in some fish continues to rise. He said (in the same article), “Out of 19 data sets, we see eight where we can see a significant trend.”
In Lake Michigan, Bohr mentioned that walleye and lake trout in the Grand Traverse bays show an increase of mercury content. Scientists can also see the same trend in Lake Huron in the walleye from Saginaw Bay and the lake trout found in Thunder Bay. Lake Erie also shows mercury level rising. The aquatic biologist said that the average increase of mercury level reaches up to 2% annually.
For the meantime, the increasing level of mercury toxicity remains in isolated areas.
Scientist Hypothesis-are storms to blame?
Ecotoxicologist of Environmental Canada, Shane De Solla believed that the warming of the Great Lakes shows a key factor in the trend. De Solla, the co-author of the research said, “The lakes are slightly warmer, and that increases the production of methyl mercury.”
Richards also mentioned that the region’s regular strong storms in the past years can also affect the Great Lakes. She said, “That results in a lot of flooding, and the re-suspension of sediments, what was buried before can become exposed, and that can increase the conversion of mercury to methylmercury.”
Meanwhile, Bohr mentioned about the invasive species which “significantly changed the food web.” These invasive species significantly altered the fish diets.
He said that in Saginaw, Thunder bays, and Grand Traverse carp are not showing any increase in mercury levels. Bohr added that in the Detroit River and St. Clair River carp are even seen decreases in mercury. He believed that the findings show important clues because carp being bottom feeders and eat differently from big sports fish.
Bohr said that carp are “low on the food chain” and “mucking around on the bottom eating insects, basically.”
De Solla believed that the mercury level in the Great Lakes will not cause any “catastrophic in the next little while.” However, if it continues to increase then “it could become a problem again.”
Mercury levels found in the fishes remains below the US Environmental Protection thresholds. Nevertheless, researchers want to establish if the reported mercury level is a temporary condition or will cause an environmental concern.
Billions worth of fish industry possibly effected
The outcome can greatly affect Michigan’s fishing industry. The data of The Michigan Department of Natural Resources concluded that anglers spent at least $2.4 billion in equipment and trip-related expenditure in 2011.
What Can We As Michigan Residents Do?