The Associated Press

Many sunbathers who want to take a dip in the cool water to escape the summer heat are being thwarted by high bacteria levels in water at popular beaches across New England.

The Massachusetts Department of Public Health reported that 78 public beaches were closed Wednesday, mostly because of high levels of bacteria. Nearly a dozen beaches and bodies of water in New Hampshire were also under some sort of advisory. In Maine, eight beaches were closed because of contamination. There was no swimming at 10 state parks in Vermont.

Most of the closures were because of high levels of E. coli associated with waste. Others were for algae blooms, some of which can be toxic.

Some of the high levels of bacteria in lakes and ponds can be linked to heavy rainfall that caused flooding and contamination, including agricultural runoff. That’s also contributing to problems in coastal waters.

Swimming in contaminated water can cause problems skin rashes to gastrointestinal and respiratory issues.

Environmental groups have called on Massachusetts officials to take steps to stop sewage overflows and pollution runoff.

Last year, 274 Massachusetts beaches were potentially unsafe for swimming on at least one testing day, according to Environment Massachusetts Research & Policy Center’s latest report on bacteria testing.