With all the recent news around swimming advisories and beach closings – it is easy to become concerned about our local water bodies where we go to swim, fish, or enjoy the view. Ohio Sea Grant, the Ohio Environmental Protection Agency and many other state and local agencies work to provide up-to-date information on our local water resources. Here’s some more information about your water quality and where to look to find information about keeping you and your family safe while also being able to take advantage of the wonderful recreational water resources Ohio has to offer.
Ohio Sea Grant and Stone Laboratory will host a free public webinar on Thursday, July 12 from 11 a.m. to 1 p.m. to explain NOAA’s 2018 Seasonal Forecast of Harmful Algal Blooms (HABs) for Lake Erie, including expert commentary, a discussion of the history of this issue on Lake Erie, Ohio’s response to the problem, and a Q&A session.
Registration is required.
Harmful Algal Bloom – what’s that?
Microcystis, and Planktothrix, and Dolichospermum oh my! Those names may sound foreign to you, but those are all species of harmful algal blooms, or HABs – any large increased density of algae that is capable of producing toxins. The HABs sighted on Lake Erie – and in some inland water bodies – tend to be cyanobacteria, also called blue-green algae.
Where and when do HABs start in Lake Erie?
Because blue-green algae prefer warm water and high concentrations of phosphorus, they usually occur first in Maumee Bay at the mouth of the Maumee River and in Sandusky Bay at the mouth of the Sandusky River. Both bays are very warm and shallow and the watersheds of both rivers have very high percentages of farm land (the Maumee is the largest tributary to the Great Lakes and drains 4.2 million acres of agricultural land). As a result, both streams contain very high concentrations of phosphorus. E coli at beaches is the result of sewage, pet, or livestock waste from a nearby discharge or stream, and is not related to a harmful algal bloom.
How do I know whether it is safe to swim?
- Before traveling, it may be a good idea to google the beach you’re visiting, and if possible call them to ask about any active advisories or warnings. One good resource is the ODNR Office of Coastal Management’s list of publicly accessible Lake Erie beaches at http://coastal.ohiodnr.gov/gocoast.
- See Ohio Algae Information for Recreational Waters – http://epa.ohio.gov/HAB-Algae for the most up to date information, and see the Ohio Beach Guard Recreational Swimming Advisories – http://publicapps.odh.ohio.gov/beachguardpublic/ page for beach advisories.
- At the beach, look for orange or red signs – those indicate the two types of harmful algal bloom advisories/warnings.
- An orange sign (advisory) means the water contains some toxin. Children and the elderly, people with health problems, and pets should avoid contact with the water.
- A red sign (warning) means toxin levels are too high and everyone should avoid contact with the water.
- If there are no signs, but the water looks bright green or has floating green scums, the Ohio EPA recommends a “when in doubt, stay out” approach.
- Even if a beach has an advisory or warning posted, activities on land are perfectly safe, so there are still ways to enjoy a day at the beach.
What do toxin levels mean?
The World Health Organization (WHO) sets the maximum allowable concentration of microcystin in drinking water at 1 part per billion (ppb) — about equivalent to 1 drop of toxin in an Olympic-sized swimming pool. Ohio has followed that recommendation so far, but is expected to convert to U.S. Environmental Protection Agency (EPA) guidelines soon, which advise microcystin limits of 0.3 ppb for children under 6 and 1.6 ppb for the general population.
If toxins have been detected in one part of the lake, is the water in the whole lake unsafe?
Blooms are generally limited by water currents, winds and where nutrients enter the water. Toxin can persist in the water for more than 30 days, but is rapidly diluted and quickly reaches safe levels when the bloom dissipates and as one moves away from the bloom. Water treatment plants in Lake Erie’s western basin routinely monitor the water they bring in for human use, so affected areas can know about a problem quickly.
How is toxin removed from the water?
Water treatment plants use activated charcoal (also called activated carbon), as well as UV rays and other techniques, to remove toxic substances from the water. The toxins, such as microcystin, bind to the charcoal particles, which are then filtered out of the water again.
What about Lake Erie fish? Are they safe to eat?
The Toledo Blade has reported on this question. As long as standard guidelines are followed, such as properly cleaning and rinsing fish fillets, the Ohio Department of Natural Resources considers fish from the lake safe to eat.
What about drinking water advisories?
You can find a list of drinking water advisories on Ohio EPA’s Drinking Water Advisory GIS tool: http://oepa.maps.arcgis.com/apps/webappviewer/index.html?id=5b1c1a32a7954cedb094c11dc7fd87b7
Be sure to follow Ohio Sea Grant for the most up to date info this summer! I recommend taking a look at our recent video on Harmful Algal Blooms: https://www.youtube.com/watch?v=CvEJHzFzIL4.
NOAA Lake Erie Harmful Algal Bloom Bulletin: https://www.glerl.noaa.gov/res/HABs_and_Hypoxia/bulletin.html
Frequently Asked Questions about Harmful Algal Blooms: http://ohioseagrant.osu.edu/research/issues/habs/faqs
Ohio Algae Information for Recreational Waters: http://epa.ohio.gov/HAB-Algae