Too much nitrogen can turn Casco Bay from a healthy blue to an unhealthly green.
On a rainy July 10, at precisely 10:10 a.m., 97 volunteers for Friends of Casco Bay hung out over docks or trudged through mud to collect jars of seawater. The analysis of their samples from sites along the Fore River in Portland and South Portland will increase our understanding of nitrogen levels in Portland Harbor. When we receive the lab results, our science staff will construct a map to show nitrogen concentrations at various sites around the harbor.
Already, these efforts have accomplished one of the main goals of the project: to explain to the public that excess nitrogen is one of the factors responsible for turning our mudflats an unhealthy green. All living things need nitrogen to grow, but an overdose can trigger excessive growth of nuisance algae, reduce water clarity, and lower oxygen levels. Sources of excess nitrogen in coastal waters include sewage, pet wastes, decaying plants and animals, and burning fossil fuels.
We partnered with Maine Department of Environmental Protection and the City of South Portland, and we raised funding for the project from Maine Outdoor Heritage Fund, RBC Blue Water Project, Casco Bay Estuary Partnership, Bowdoin College Common Good Grant, and our generous members.