Document Type

Fact Sheet

Publication Date



NUTRIENT POLLUTION IN CASCO BAY: AN EMERGING ISSUE • Nutrient pollution is emerging as one of Casco Bay’s most challenging problems. We usually think of “nutrients” as things that make food nutritious, but when we add excess nutrients to coastal waters, it boosts plant growth, which has many unintended consequences. • Due to our region’s relatively low population, Casco Bay’s water quality is generally excellent compared to other coastal bays close to urban and suburban areas. However, the Bay is beginning to experience effects of excess nutrients. • In Casco Bay, nutrient pollution is principally caused by excess nitrogen entering the Bay. • Several areas in Casco Bay are of greatest concern: Portland Harbor, the Harraseeket, the Royal River, and the upper New Meadows.


CBEP is funded by the US Environmental Protection Agency under Cooperative Agreements #CE96190301, #CE00A00063, and #CE00A00299-0 with the University of Southern Maine.


Casco Bay, Casco Bay watershed



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.