[USA] The open waters of Lake Erie are a little less of a scary blue-green this week as the microcystis cyanobacteria bloom west of West Sister Island is producing less toxic microsystin.However, scum areas produced by blooms remain a significant risk to boaters and lake inhabitants. And the harmful algal bloom (HAB) in Grand Lake St. Marys still has residents and recreaters seeing red due to a recreational no contact advisory.
Although some speculate that this is the new norm on Grand Lake, scientists, officials and members of the Ohio agricultural industry haven’t given up that water body’s ghost. And the fishing and tourism industries, plus the 12 million people who live in the Lake Erie watershed (11 million of whom get their drinking water from Lake Erie itself), are arming themselves for the battle against the bloom, or at least a fight that will keep the health of the shallowest Great Lake from collapsing altogether.
This spring, the National Centers for Coastal Ocean Science and Great Lakes Environmental Research Laboratory began arming the general populace with what it has learned since blue-green algae became a growing concern in the 1990s. Although the Ohio Department of Natural Resources, Ohio Department of Health and Ohio Environmental Protection Agency have for several years posted consumption and ‘get off the beach’ advisories, in April 2015 the Lake Erie Harmful Algal Bloom Bulletin compiled data collected by the National Water Quality Laboratory at Heidelberg University to predict the likelihood of HAB. When heavy rains in June flushed fields in what is referred to as nutrient loading, the predictions quickly changed from ‘if’ to ‘when and where’ HAB would be.
At Ohio State University’s Stone Laboratory on Gilbratar Island, research is conducted during the summer months by people like Dr. Justin Chaffin, Research Coordinator, Ohio Sea Grant and OSU Stone Lab. Chaffin recorded “Christmas in July”: this year’s highest level of microcystis cyanobacteria off Stone’s Lab docks which faces the popular tourist destination, Put-in-Bay.
With your Average Joe warned with a weekly report of HAB, scientists continued to monitor just how harmful this year’s HAB would be. What they found is that, although 80 percent of the green in Lake Erie this summer was microcystis cyanobacteria, the trigger that caused this ‘blue green algae’ to release microcystin toxin as it did in August 2014 wasn’t there. Researchers in Canada and the U.S are speculating that one form of nitrate wasn’t as prevalent in Lake Erie watershed runoff this spring.
Still, blue-green algae isn’t a lake food chain staple. Diatom algae are. These were absent from all lake water samples collected at Stone Lab in August, except for one sample collected on Aug. 10.
“We’re the walleye captal of the world,” said Dr. Chris Winslow, Interim Director, Ohio Sea Grant College Program at Stone Lab. “‘Bassmasters’ magazine’s most recent ranking of the top 10 lakes for smallmouth bass ranked Lak Erie as 22. It’s a great fishery. We have no problem being a lake that has enough nutrients to support that web. It’s that situation right now where we have too much of a good thing. The phosphorous loadings here have pushed our algal growth too far.”
Stone Lab has reached out to charter boat captains to help with monitoring water conditions, including algal growth. Currently, six captains collect a sample weekly after fishing. Stone Lab retrieves the sample and analyzes it.
In the Port of Toledo, scientists are working with the ag community to make good use of sediments that are dredged from the river and mouth of the bay each year, including silt from the 5,024 square miles land that drain into Lake Erie from the Maumee River watershed. Those sediments are now part of the “Dredging Center of Innovation,” an agricultural improvement research facilty built along the mouth of the Maumee River of reclaimed sediment.
Along the north coast of Lake Erie’s western basin, the Ohio Coastal Management Program is identifying restorable wetlands through the Healthy Lake Erie Fund. “We’re starting to reconnect these wetlands for fisheries and habitat benefits; maybe for nutrient processing benefits,” said Dr. Scudder Mackey, Chief of The Office of Coastal Management at Ohio Department of Natural Resources.
Jim Hoorman, Assistant Professor and Extension Educator with Ohio State University Extension Putnam County, is working diligently with local farmers to use cover crops —in the right combinations— to keep phosphorous and nitrogen out of the water altogether. Last Thursday, Hoorman led a cover crop conservation farm tour at the Terry and Dennis Turnwald Farm, outside Cloverdale. At that site, 12 cover crop plots were planted on July 29 with four different treatments. The event drew people from Putnam County as well as from Akron, Cleveland and Toledo.
When asked which cover crop combo help keep soil on the field and not in waterways, Hoorman said, “We like to see grasses, legumes and/or brassicas that survive the winter.” He added that mixtures heavy on grasses that survive the winter are best at incorporating phosphorous and and nitrates in the soil.
As all of these measures are taken to combat HAB and the growth of Lake Erie’s “dead zones” — areas with little or no dissolved oxygen due to decomposing algae — all players know the game is ongoing as they must keep one step ahead of altering weather patterns. No matter who is responsible, why or with what frequency the Earth’s climate is changing, researchers no sooner find a key to what makes HAB tick, only to find an exception to a solution.
For instance, the winters of 2014 and 2015 were particularily cold in much of the United States, including Northern Ohio. As thick layers of ice formed across the surface of Lake Erie, all the scums and HAB froze right along with the water. Problem solved, right?
Maybe not, according to Dr. Mike McKay, Bowling Green State University’s Department of Biological Sciences. He has spent a great deal of time on Lake Erie during the winter months and has seen an overall decline in ice cover. McKay and other researchers measure light penetration through the ice. They have found that typical years of ice cover prevent winds from mixing sediments up in the water and keep cold-loving diatom algae at healthy levels. McKay said little ice cover in 2012 resulted in an 80 to 90 percent decline in this biomass.
“I think a future Lake Erie may be one of little to no winter ice. This may be increasing in frequency, consistent with climate warming,” said McKay. “Does it matter? Maybe, maybe not. The ecosystem could readjust itself. Right now there are major food web implications. Will we see a dip in fish populations down the road? That remains to be seen.”
There is good news on the horizon, however, which may come yet this year. Humans who turn on their taps in HAB areas of concern may still be able to safely drink the water, no matter what color the flow. Later this summer, with monies from the Lake Erie Protection Fund, scientists hope to discover if pitcher-style water filters can remove microcystin.
View original article at: What color is your water? Research leads to answers, more questions