Portland, Maine–The chemistry of the water in Casco Bay is changing, and not for the better. It is also changing more rapidly than anyone could have predicted. Those are some of the key conclusions in the report, A Changing Casco Bay, released by Friends of Casco Bay on April 28th.
The report answers the question, “How healthy is Casco Bay?” Decades of research by the conservation organization suggests that our Bay, though generally healthy, is facing an uncertain future.
The coastal waters of Maine’s most populous region are becoming more acidic, making it harder for shellfish, such as clams, oysters, and mussels, to build and maintain their shells. As the water becomes more acidic, shell-building material—calcium carbonate—dissolves back into the water.
The threat to our coastal waters comes from an innocuous sounding source: nitrogen, which is found in fertilizers, sewage, and pollution from smokestacks and tailpipes. Data collected by Friends of Casco Bay’s professional staff and volunteer citizen scientists show a very clear trend of higher nitrogen levels and lower oxygen levels closer to shore.
Scientists and clam harvesters already are seeing the effects in Casco Bay. Research by Friends of Casco Bay on clam flats has found a disturbing link between acidic mud and clam flats where it is no longer profitable for clammers to harvest shellfish. That could be critical to Maine’s softshell clam fishery, which was valued at $19,226,987 in 2014, second only to lobster harvesting.
Changes that are happening in Casco Bay mirror what is happening worldwide. Globally, ocean temperatures are rising and pH is dropping (becoming more acidic)—these are frightening trends, happening at alarming rates.
The good news is that it is possible to slow the impacts of acidification, at least in coastal waters like Casco Bay, by making simple lifestyle changes. Cathy Ramsdell, Friends of Casco Bay’s Executive Director/Casco Baykeeper Pro Tem, says, “Overall, Casco Bay is in good shape, but nitrogen is a threat to marine life. There are things that each of us can do to make the Bay healthier. The report lists 59 actions to consider, any of which can make a difference in the health of Casco Bay ultimately. Surely, at least one of these will fit your lifestyle. It takes a community to protect the Bay.”
Friends of Casco Bay, 28 April 2015. Press release and report.
