By JULIA ROEDER<\/p>\n
Capital News Service<\/p>\n
LANSING \u2014 Every spring, as the Great Lakes region warms, scientists watch for the return of harmful algal blooms.\u00a0<\/p>\n
While the average passerby doesn\u2019t notice the blooms until the bright green layer covers the shoreline, scientists can begin predicting the blooms weeks or even months before they become visible.\u00a0<\/p>\n
Harmful algal blooms are rapid growths of toxin-producing bacteria that infiltrates drinking water, threatens wildlife and poses health risks to people and pets.<\/p>\n
The forecasts for the blooms are important not only for beachgoers, but also for fishers and businesses that depend on the Great Lakes.<\/p>\n
While harmful blooms occur throughout the Great Lakes, the National Oceanic and Atmospheric Administration (NOAA) currently issues seasonal forecasts only for western Lake Erie, which has the right combination of nutrients, weather and decades of scientific data to forecast, compared to the other lakes.<\/p>\n
The reason for forecasting the lake is simple: Lake Erie\u2019s algal blooms can threaten drinking water, recreation and the local economy.<\/p>\n
While NOAA\u2019s short-term forecasts help track blooms as they develop over the span of a few days, the seasonal outlook looks months ahead. These predict how severe the bloom is likely to be, based primarily on phosphorus levels in the Maumee River.<\/p>\n
The Maumee flows from Indiana east through Ohio, ending in Toledo, where it drops off into the western side of Lake Erie. Agriculture along the waterway dumps phosphorus from fertilizers into the river, which carries nutrients to the lake.\u00a0<\/p>\n
When too much phosphorus enters Lake Erie, it acts like fertilizer, feeding algae and driving the harmful blooms that spread across the lake.<\/p>\n
\u201cThe main factor that impacts how bad a bloom is going to be is the amount of nutrients,\u201d said Gregory Dick, the director of the Cooperative Institute for Great Lakes Research at the University of Michigan.<\/p>\n
Dick said NOAA\u2019s seasonal outlook focuses on bloom size rather than location in the basin because winds, lake currents and weather determine how algae moves and accumulates throughout the summer.<\/p>\n
\u201cThe seasonal forecast is essentially predicting how bad the bloom is going to be that year,\u201d Dick said. \u201cIt\u2019s not making specific predictions about when or where the bloom is going to be.\u201d<\/p>\n
Every year in late June, NOAA releases its seasonal forecast for western Lake Erie. This year, the agency predicted a\u00a0moderate\u00a0bloom. By mid-July, the first visible signs of cyanobacteria had begun appearing in parts of the lake\u2019s western side.\u00a0<\/p>\n
Algae on its own is not the problem. It is a naturally occurring part of the Great Lakes ecosystem, and the base of the food chain \u201cthat feeds the small shrimp-like organisms that then feed the fish and everything else in the lake,\u201d said Thomas Bridgeman, an ecology professor and director of the Lake Erie Center at the University of Toledo.\u00a0<\/p>\n
Problems begin when extra nutrients, like phosphorus or nitrogen, wade into the lake, prompting an overgrowth of algae and rapid reproduction of certain bacteria. One of the more harmful kinds is cyanobacteria, which behave like algae but produce dangerous chemicals.<\/p>\n
\u201cIf they get into drinking water supplies, or if they wash up on beaches and people or dogs are exposed, they can be made very sick or even die,\u201d Bridgeman said. <\/p>\n
These dangers became\u00a0clear\u00a0in 2014 when toxins from a harmful bloom contaminated Toledo\u2019s drinking water.<\/p>\n
Although nutrients drive most of the bloom\u2019s growth, weather determines how much phosphorus reaches the lake from agricultural fields.<\/p>\n
\u201cIn years when we have much more rainfall, there\u2019s much more runoff, and that washes more phosphorus into the lakes and causes bigger blooms,\u201d Dick said.<\/p>\n
Rick Stumpf, an oceanographer who leads NOAA\u2019s harmful algal bloom forecasting efforts at the National Centers for Coastal Ocean Science, noted that not all rainy springs look the same.<\/p>\n
\u201cA wet spring could be because it just keeps raining, or because there\u2019s a week of intensive rain,\u201d Stumpf said. \u201cThe worst blooms occurred when there have been floods in the Maumee River Basin.\u201d<\/p>\n
Rising lake temperatures from global warming add more uncertainty to predicting blooms.<\/p>\n
According to October data\u00a0from\u00a0NOAA\u2019s Great Lakes Environmental Research Lab, all five of the lakes were around 4 to 5.5 degrees Fahrenheit warmer last fall than their long-term average for the last three decades.<\/p>\n
Dick said warming temperatures also extend bloom seasons across the Great Lakes.\u00a0<\/p>\n
Calm weather on the lakes favors blooms because of how mobile the algae can become.\u00a0<\/p>\n
Stumpf said, \u201cWinds matter because these blooms do better in calm water. If it\u2019s calm, they float up to the surface and block the light, keeping the competition down.\u201d<\/p>\n
Once a bloom begins developing, forecasting shifts from seasonal to daily predictions.<\/p>\n
\u201cSatellite data is a key piece because we can determine how much bloom there is over the whole lake every clear day,\u201d Stumpf said. \u201cThat\u2019s way more data than you can possibly get from field sampling and way cheaper.\u201d<\/p>\n
Satellite imagery distinguishes harmful cyanobacteria from beneficial algae that forms the base of the food chain.\u00a0<\/p>\n
There are two types of algae forecasts from NOAA \u2014 one predicts long-term, months in advance, and another is short-term, days in advance.\u00a0<\/p>\n
NOAA\u2019s short-term Lake Erie forecasts combine satellite observations with predictions of wind and water currents<\/p>\n
\u201cSatellite images can tell us where the bloom is now,\u201d Dick said. \u201cThe forecast can tell us where the bloom is expected to go in the next few days based on forecasts of wind and water currents.\u201d<\/p>\n
Stump said short-term forecasts can help know what to expect over three or four days.<\/p>\n
Still, forecasting has its limitations.<\/p>\n
\u201cYou can always make a prediction,\u201d said Dan Obenour, a professor in the Department of Civil Construction and Environmental Engineering at North Carolina State University. \u201cAs you go further and further out in the future, the uncertainty increases. At some point, the forecast becomes useless.\u201d<\/p>\n
Researchers have found that conditions through late June provide the most reliable window for forecasting Lake Erie\u2019s harmful blooms.<\/p>\n
By June, scientists can estimate how large the harmful bloom is likely to grow over the summer, Obenour said. This is largely determined by the amount of phosphorus that washed into Lake Erie during the spring.<\/p>\n
\u201cFor Lake Erie, we can only forecast a few months ahead,\u201d Stumpf said. \u201cWe can\u2019t forecast further than our confidence in the weather models.\u201d<\/p>\n
Outside of Lake Erie, forecasting continues to be more difficult.\u00a0<\/p>\n
\u201cWe don\u2019t understand all the factors yet,\u201d Stumpf said. \u201cThe Lake Superior blooms are very event-related, so there\u2019s no way we could forecast those far in advance.<\/p>\n
Although there are still limitations to predicting blooms, researchers are looking to improve forecasting.\u00a0<\/p>\n
Dick said one of the biggest challenges is predicting toxicity rather than bloom size.<\/p>\n
Stumpf said, \u201cWe\u2019re now trying to forecast not just how big the bloom will be, but how scummy it will become and how long it will last.\u201d.<\/p>\n
He said forecasting helps scientists learn important lessons for preventing future blooms.<\/p>\n
\u201cOur ability to forecast blooms means we have a good understanding of the factors that cause them,\u201d he said. \u201cKnowing that phosphorus in the spring is the key factor helps guide efforts to keep phosphorus off farm fields.\u201d<\/p>\n
Julia Roeder is an environmental reporting intern through a partnership with Capital News Service, MSU Knight Center for Environmental Journalism and the Mott News Collaborative. This story was produced for Great Lakes Now\/Detroit PBS.<\/p>\n","protected":false},"excerpt":{"rendered":"By JULIA ROEDER Capital News Service LANSING \u2014 Every spring, as the Great Lakes region warms, scientists watch…\n","protected":false},"author":2,"featured_media":290714,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[120594,120595,136,138,137,120596],"class_list":["post-290713","post","type-post","status-publish","format-standard","has-post-thumbnail","category-erie","tag-capital-news-service","tag-cns","tag-erie","tag-erie-headlines","tag-erie-news","tag-great-lakes-echo"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/posts\/290713","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/comments?post=290713"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/posts\/290713\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/media\/290714"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/media?parent=290713"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/categories?post=290713"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-pa\/wp-json\/wp\/v2\/tags?post=290713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}