Warmer temps increase threat of toxic algae

Warmer temperatures and high acidity in the Inland Bays could feed toxic algae in the future, but so far this year, algae blooms have been minimal.

“We haven't had any big blooms of toxic algaes, but there is a potential to become worse as weather becomes warmer and water becomes more acidic,” said Marianne Walch, science and restoration coordinator for the Delaware Center for the Inland Bays.

On July 26, University of Delaware researcher Nayani Vidyarathna presented her findings on potential toxic algae blooms to the Scientific & Technical Advisory Committee of the Center for the Inland Bays, showing how lower pH levels and rising water acidity could cause algae growth, which is harmful to fish and sea life.

“It can happen in the Inland Bays if water temperature and carbon dioxide increases,” she said.

Scientists who monitor the Inland Bays say there have been no major algae blooms this season or year.

“This year is more normal. Not as wet,” said Ed Whereat, of the Citizen Monitoring Program for University of Delaware. “The blooms that can kill fish are few and far between...The spring bloom didn't really occur, or we didn't catch it.”

There appears to be a micro algae bloom near the Burton Island power plant, but CIB scientist Andrew McGowan said overall micro algae is also down this year. “The water is far more turbid, so I'm not sure why it's down,” he said.

Walch said she was unsure whether better land management along Bethany Beach's canals has limited the amount of fertilizer that runs into the waterways – a usual suspect for algae blooms in the Inland Bays. A sharp drop in rainfall over last year's very wet summer is likely a big reason algae blooms are down.

“In those wet years, we see bigger blooms,” she said.

This year, Walch said, bay grass in the Inland Bays is growing nicely which is a good sign of healthy water. “This may mean water quality is improving,” she said.