Some nitrogen is a natural part of the ecosystem. Our goal is to do something about the man-made sources of nitrogen - or controllable nitrogen. Here are some of the most common sources in Bass River:

  • Septic Systems (82%)
  • Runoff
  • Fertilizers (8%)
  • Agricultural activities
  • Landfills
  • Wastewater treatment facilities

Waterways up and down Nantucket Sound are dealing with the problem of excessive nitrogen. A recent and alarming joint report by the Buzzards Bay Coalition and the Woods Hole Research Center demonstrates that nitrogen has caused a significant decline in area salt marshes. Scientists found that the total area of salt marshes on the Westport River have consistently been reduced during the past 80 years, and dramatically so in the past 15 years. Altogether, the six islands in the study lost a total of 12 acres of salt marsh since 1938. Scientists warn if marsh losses continue at the accelerated rate observed during the past 15 years, the Westport Rivers’ marsh islands could disappear entirely within 15 to 58 years.

what happens when there's too much nitrogen?

  • Increases in macro algae (the dreaded “red tide” or “rust tides” we are more frequently hearing about )
  • Decreases in dissolved oxygen concentrations that threaten aquatic life (cloudy, murky water)
  • Reduced diversity of benthic animal populations (those are the species which inhabit the lowest levels of the waterway and are essential to the food chain)
  • Significant loss of eelgrass habitat
  • Periodic algae blooms (when we see clusters of the green or even brown slimy stuff floating on the surface of the water)
  • Left unchecked, these problems can become even more severe and include:
    • Periodic fish kills
    • Unpleasant odors and scum
    • Further reduction or near total loss of the benthic animal communities

And these are not just dire doomsday predictions from overzealous scientists. These are real problems that Florida faced just last year:

Slimy Green Beaches May Be Florida's New Normal (National Geographic)

Miles of Algae and a Multitude of Hazards (New York Times)

10 Things to Know About Florida's Harmful Algae Blooms (

Without careful management and attention to this silent pollutant, there is the risk that future generations will not be able to enjoy Bass River the way that we have.