Do fish you eat carry blue-green algae toxins?

MARTIN COUNTY – The toxic blue-green algae blooms are gone, but the effects may not be.

The Ocean Research & Conservation Association wants to find out if fish people eat from the St. Lucie River and Indian River Lagoon in Martin County are tainted with toxins from blue-green algae.

And if you catch fish in the river and lagoon, you can help them find out.

"The idea is to see if toxins in the blue-green algae are transferring from the algae to fish," said ORCA research scientist Beth Falls, "and from the fish into the people who catch and eat them. Basically, we want to see if there's a problem in our waters that needs more research."

Researchers at the Fort Pierce-based nonprofit want to look at all types of fish that people eat from waters throughout Martin County: the lagoon, the north and south forks of the St. Lucie and the canals that run into the river.

The goal is to get 50 edible-size fish, she said. "More would be great."

The research is being funded by a $30,000 grant from the Guardians of Martin County.

Targeting a toxin

ORCA will look specifically for microcystin, the most common toxin in the blue-green algae blooms that blanketed a wide swath of the river in and around Stuart in 2016.

As algae is eaten by tiny animals in the estuaries, and as those animals are eaten by larger ones, the amount of microcystin increase. That mean fish eaten by humans could have high levels of the toxin. Scientists call that process bioaccumulation.

"We know that microcystin bioaccumulates, at least in laboratory experiments," Falls said. "What we don't know is how much it builds up in fish in our local waters and how much of a risk it is to people who eat those fish."

Researchers will look for the toxin on the fish's skin, in its liver and in its meat.

"We're trying to connect the dots," Falls said. "If the toxin is in the water, does it get on the fish and in the fish? If it gets in the fish, it'll go to the liver first. Then, does the liver filter it out or does it get into the meat?"

Bloom or no bloom

Fish big enough to eat now were around during the 2016 algae bloom and perhaps previous blooms caused by massive Lake Okeechobee discharges in:

April 2003 to April 2004 (163.2 billion gallons)

September 2004 to April 2006 (457.2 billion gallons)

March to September 2010 (83.7 billion gallons)

Discharges in 2013 (136.4 billion gallons) and 2017 (192 billion gallons) didn't cause widespread algae blooms.

But in 1998, a year of massive Lake O discharges, thousands of fish from 33 species in the lagoon from Melbourne to Jupiter died or got open lesions on their skin.

Even when there's no floating guacamole bloom on top of the water, there's blue-green algae in the water, Falls said, and there are tiny critters eating it.

Blue-green algae also contain a toxin called BMAA suspected of triggering neurological diseases such as Alzheimer's, Parkinson's and amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig's disease.

Fish used in the study will be frozen so they can be tested for other toxins in future studies, Falls said.

Angling for research

Anglers who are willing to cooperate in the study should contact Falls before the study begins.

"We need to know as much as possible in advance where people are going to be fishing and what they'll be fishing for," Falls said. "That will give us an idea of what to expect."

Fishermen will have to turn over an entire fish and provide information, including the time and date it was caught and the GPS coordinates of where it was caught.

ORCA staff are working with area bait shops to act as drop-off points.

Will local fishermen participate?

"Absolutely," said Jonathan Earhart, owner of Chaos Fishing Charters in Stuart. "I've got 20 to 30 fishing buddies who would be happy to hand over a fish if it's for research to help the water."

How to help

Anglers willing to cooperate in the search for blue-green algae toxins in fish from the St. Lucie River and Indian River Lagoon in Martin County should contact Beth Falls before the study begins May 1 at:

bfalls@teamorca.org

772-467-1600