The State Of Nantucket Harbor

While the Town of Nantucket has made progress toward improving the quality of Nantucket Harbor, several key metrics show that the harbor is still well short of the town’s goals and further action is required.

The findings were presented Tuesday by the Natural Resources Department (NRD) during the 6th annual State of the Harbor forum presented by the Nantucket Land Council.

The data presented by the NRD painted a picture of a harbor that has started to show signs of recovery but is still ravaged by decades of damage. Nitrogen levels in Nantucket Harbor have declined over the last ten years but are still above target levels in many places, and despite significant protection and replenishment efforts, Nantucket Harbor has still lost about 30% of its eelgrass since 1990.

The department outlined the progress that has been made toward the goals defined in the 2009 Nantucket & Madaket Harbors Action Plan, and the changes the NRD expects will be made in the upcoming year to update to the plan.

The main change Natural Resources Director Jeff Carlson highlighted was the incorporation of coastal resilience and the town’s Coastal Resilience Plan, absent from the 2009 version of the Harbors Action Plan.

While water resource specialist Thaïs Fournier said the water quality in Nantucket Harbor is generally good, she added that the over-abundance of nitrogen can lead to explosions of dense algal growth. The algae can then choke eelgrass and animal life in a process known as eutrophication.

Preserving the harbor’s eelgrass is critical because eelgrass mitigates erosion and flooding and is also the primary habitat for Nantucket bay scallops. The decrease in eelgrass has been correlated with a dramatic crash in the island’s bay scallop harvest. The collapse of the bay scallop fishery has a significant impact on local scallopers, as well as on the scientists working to preserve shellfish, as they rely on money from the ever-shrinking pool of commercial scalloping licenses to fund their efforts.

Despite this, 75 percent of the action items in the Nantucket Shellfish Management plan have been accomplished, including renovations to the Shellfish Hatchery and a major shell recycling program intended to stimulate oyster growth.

To reduce eutrophication and improve water quality in the Nantucket and Madaket harbors, the NRD recommended that Nantucket residents switch from septic systems to Town sewer. The Town’s sewage treatment facility is far more sophisticated than what septic systems offer and removes a much higher percentage of nitrogen from waste. Additionally, the NRD suggested residents stop using fertilizer whenever possible, plant native vegetation and rain gardens in their lawns to reduce runoff, use EPA safer choice cleaning products, pick up pet waste, and limit vehicle usage, among other things.

The action plan, which has to be approved by the state, guides the Town’s use of the Nantucket and Madaket Harbors and the surrounding land. The NRD will receive assistance from the Urban Harbors Institute at UMass Boston and the Woods Hole Group in drafting its update to the plan. This is a lengthy process that will involve reviewing the 2009 plan and the status of its recommendations and any relevant studies released since 2009, as well as numerous interviews with stakeholders and opportunities for public comment.

The State of the Harbor forum was held at the Nantucket Yacht Club. For those who missed the forum, it will be available on Nantucket Community Television’s YouTube page within the next two weeks.