Report: Chemistry of Maine's Casco Bay Changing Rapidly

Apr 28, 2015

PORTLAND, Maine - A new study reveals rapid changes in the chemistry of the water in parts of Casco Bay. Using more than 20 years worth of data, the environmental group Friends of Casco Bay has found high levels of nitrogen and low oxygen levels in a number of coastal locations. And that has worrying implications for Maine's shellfish industry.

Environmental advocates, local business owners and residents gathered by Portland's waterfront Tuesday morning to unveil a long-awaited update on the health of Casco Bay. The report has been more than two years in the making and taps into at least two decades worth of data. To be clear, the study's overall conclusions are not that bad.

"Generally speaking the Bay is in good health," said Mike Doan, a research associate with Friends of Casco Bay, which published the report. He points to a map containing a health index of the bay. Many areas are marked green or yellow - meaning the waters there are in good or fair health, with relatively manageable pH levels of acidity.

"From the bird's eye view, things are in good shape," Doan said. "Where we have problems are in some small local regional areas that we're trying to focus on."

Those are the five areas on the map that are marked red - from New Meadows Lake near Bath, to Peabbles Cove, near Cape Elizabeth - all of them close to the shore.

The water is more acidic at those sites and oxygen levels are lower, says Doan. And there's a correlation, he says, between this and higher levels of nitrogen: a chemical considered essential to plant growth on land, but which is harmful if too much of it ends up in the ocean.

"The thing we're most concerned about right now is acidification," he says. "Another negative consequence of having too much nitrogen - our waters, our muds - our clam flats - are becoming more acidic," which, as many in Maine already know, is having a damaging effect on some of the state's shellfish harvest.

"Clear water doesn't necessarily mean it's clean. You can't see nitrogen in the water," says Jennifer Fox, the co-owner of Andy's Old Port pub on Portland's waterfront. "Some of the ways that it's impacted us as business owners is that we've actually seen the Maine foods that we're proud serve aren't available to us any more."

Gulf of Maine shrimp have been off the menu for the last three years now, she says, while the scallops have become less available every year as the season gets shorter and shorter.

Researcher Mike Doan says one of the biggest culprits behind higher nitrogen levels is increased runoff caused by higher rainfall levels mixed with pollution. But he says there are measures we can take:  The report lists 59 things people can co to help improve the health of Casco Bay.

An important one, says, Doan, is to reduce the amount of fertilizer you put on your lawn. "A lot of the fertilizer you use won't all be taken up by the plants, they will run off. Or make sure you're not fertilizing before a big rain storm."

Last year, the Maine Legislature established a 16-member commission to study the effects of ocean acidification on the state's entire marine economy. In February, the panel recommended that the state issue a $3 million bond to fund further study of the issue.