Water pollution has become a major problem for Nantucket in recent years. Our harbor is vital to the economic and social well-being of the island as a source of shellfish and other seafood. A major culprit in the threat to our harbors is an overload of nitrogen. Nitrogen, as produced in nature in a healthy eco system, occurs naturally in low quantities as part of what is known as the nitrogen cycle. In this cycle, nitrogen is converted by bacteria into forms usable by plants, which then utilize the nitrogen to make food through photosynthesis. When the plants die and decompose, the cycle continues. However, problems occur when nitrogen is added to a system – usually from man-made sources – faster than it’s used by the aquatic life.
The nitrogen overloading which we can control – to some extent – results from the surface runoff of nitrogen from rich fertilizer, faulty septic systems leeching into groundwater, and other agricultural additives that pass through the island watershed into the harbor. All Nantucketers should be aware of the steps they can take to reduce the amount of nitrogen that ends up in our harbors.