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Seagrass Management

Seagrasses are Submerged Aquatic Vegetation (SAV) that create highly productive habitats in shallow coastal waters across the globe. Seagrasses are true vascular plants that have roots and make flowers, therefore not a seaweed which is macroalgae.

Eelgrass (Zostera marina) in Great South Bay.

New York Seagrass Map

The most current available seagrass maps from the Long Island Sound Study, Peconic Estuary Program, and the South Shore Estuary Reserve have been summarized to create one map of New York seagrass habitat (leaves DEC website).

Good Seagrass = Good Seafood

  • Seagrass habitat provides food to marine organisms that ultimately supports the local seafood that people eat.
  • Seagrass habitat is federally recognized as Essential Fish Habitat (EFH) (leaves DEC website) because many different commercially and recreationally important fish species utilize seagrass meadows.

Seagrass also benefits society by supporting coastal environmental quality.

  • The physical structure of seagrass helps absorb wave energy and deter erosion which supports shoreline resilience.
  • Seagrass provides resistance in currents which causes particles in the water to settle to the seabed that is stabilized by seagrass roots.
  • Seagrasses have high levels of photosynthesis which uses carbon dioxide and nutrients, resulting in improved oxygen levels and carbon storage.
Image of Eelgrass underwater
Eelgrass (Zostera marina) in Fishers Island.

Eelgrass (Zostera marina) is the dominant meadow forming perennial seagrass in New York estuaries. Widgeongrass (Ruppia maritima) is a smaller annual species of SAV that can also be found occasionally in some brackish (less salty) and estuarine waters around NY.

Unfortunately, eelgrass has been declining across NY waters. Acknowledging the importance of our eelgrass meadows and the necessity to conserve the remaining habitat, New York State legislation established a Seagrass Task Force in 2006.

  • In 2009 the Task Force prepared a report to Governor and Legislature (PDF) making recommendations on restoring, researching, preserving, and properly managing this valuable marine resource.
  • This led to passage of the "Seagrass Protection Act" (leaving DEC's website) in 2012 which prioritizes the designation of Seagrass Management Areas and developing Management Plans in consultation with local governments and stakeholders.
View some underwater video taken by the State Seagrass Coordinator on DEC's YouTube Channel: Western Great South Bay, Great Peconic Bay, Shelter Island, Fishers Island.
  • Western Great South Bay: A surprisingly impressive area of eelgrass that remains near the border of Suffolk and Nassau Counties.
  • Great Peconic Bay: A small bay in the Southampton area, off of the Great Peconic Bay, is the only place left in the western Peconic Estuary that has eelgrass.
  • Shelter Island: The eastern shore of Shelter Island still has some eelgrass, which benefits from the open tidal flushing with Gardiners Bay.
  • Fishers Island: A shallow cove on the north shore with little bubbles of oxygen (from photosynthesis) cascading away from the eelgrass through the water.

The leading threat to eelgrass health is attributed to the deteriorating water quality in our bays and estuaries that is intricately linked to cultural eutrophication caused by nutrient pollution. The Long Island Nitrogen Action Plan (LINAP) is currently developing strategies to reduce nutrient pollution and improve water quality our bays and estuaries. The implementation of LINAP could have critical benefits for the health of eelgrass, fish, shellfish, and Long Island communities.

There are many great resources for seagrass science and management information:

More about Seagrass Management: