Recently,in Lima Ohio, dogs died after drinking water from a family pond....

Asked August 18, 2019, 8:25 AM EDT

Recently,in Lima Ohio, dogs died after drinking water from a family pond. Algae was the toxin. How do we test for the algae? Our family has a pond. The dogs go in and out at will, drink from it, too.

Pickaway County Ohio pond water quality algae control

1 Response

Greetings anonymous:

A somewhat frequent problem this year. Technically, those potentially toxic organisms aren't "true" algae, although they are commonly called "blue-green algae" (technically called cyanobacteria). Regarding general information on related organisms, this fact sheet that coauthors and I first published in 2010 may still be of some use (note that the contact info it gives for me is outdated): (also, some names have changed since: Anabaena has been renamed Dolichospermum, and Lyngbya has been renamed Microseira). Here’s an article that I wrote on managing against related problems in ponds: One of the most common blooming genera in recent times is Microcystis; it tends to form bright green, streaked surface scums in calm weather. In addition to the fact sheet, note the attached images that I shot on a pond with which I'm working in central Ohio. If you see any green scums that give you pause, I strongly encourage you to restrict access by your dogs.

Regarding testing for cyanotoxins, a toxin test at a single point in time is of extremely limited utility because toxin production by a bloom can change very rapidly. Here is an excerpt from a slide presentation of mine:

Many species can produce toxins, but variably so.

  • Single point-in-time tests don’t reveal much; meaningful toxin monitoring of a bloom site over time becomes prohibitively expensive.
  • Give monitoring priority on sites used for commercial purposes (like irrigation or aquaculture), domestic water supplies, or with public contact/access.
  • Less so (like probably not at all) on sites used for casual recreation or aesthetics (instead, limit human contact and restrict access by domestic animals).

The USEPA offers this list of labs who might contract to test worrisome waters: However, it’s both a little outdated (Beagle Bioproducts, e.g., no longer exists), and it lists entities (like municipal water systems) that aren’t likely to conduct such tests on contract with individuals. With Beagle gone, I usually suggest comparing bids between these entities: and

I hope this is useful.