Year Two Eelgrass Restoration in Staten Island

In conjunction with New York/New Jersey Harbor and Estuary Program (HEP), EPA, and Stony Brook University, IEC has begun its second year of monitoring the success of eelgrass planted by Stony Brook University on the Southern tip of Staten Island in the Raritan Bay. After pausing for the winter, data collection began again in the spring and monitors survival, growth, and epiphytic coverage of the plants as well as temperature, light, dissolved oxygen, salinity/conductivity, and depth. The project was anticipated to be completed by the Spring of 2026 but it is now expanding into a second full year following the collection of this past year's data.

Three habitat surveys monitoring the plants’ survival, growth, and epiphytic coverage were conducted by IEC and showed relatively limited success of eelgrass planted in the Raritan Bay. Eelgrass prefers cool, shallow waters with little wave motion and good light penetration. The Living Breakwaters provide shelter from the waves and the water is shallow enough to support eelgrass and multiple plots of the plant survived the winter and continue to grow in this location. However, visual observations of high turbidity and low light data recorded by the light sensors deployed in the eelgrass, as well as low percent survival of the plants, suggest that this site may not be optimal for long-term success of the plants or for additional planting.

In response to these findings, IEC has begun pilot data collection at a second site to determine site suitability on the northern tip of South Beach in Staten Island. Two light sensors reading surface-level and bottom light coverage have been deployed and will provide preliminary data on whether this can be a more feasible site. IEC is expected to seed new eelgrass this fall, and this data may help inform the optimal location for the eelgrass to take root. In addition, further research is being done at the original Living Breakwater site, including core readings taken by IEC field staff to determine the material makeup of the soil as well as the presence of large particles like shells that may affect the plants’ ability to take root.

Eelgrass has several vital functions in aquatic ecosystems and can improve water quality and habitat stability, namely by absorbing nutrients, filtering water, preventing erosion, and storing greenhouse gases. However, poor water quality in the 20th century eradicated most of the eelgrass in the New York/New Jersey Harbor. Due to vast improvements in water quality since the loss of these plants, the Harbor may have the capacity to support eelgrass populations once more. This study will help determine the environmental conditions necessary to support eelgrass and the feasibility of further eelgrass restoration in the New York/New Jersey Harbor.