Eelgrass (Zostera marina) is a meadow forming marine flowering plant that is part of a worldwide group of species known commonly as seagrasses. Eelgrass is recognized as a critical nursery habitat for a variety of marine fisheries species. In Massachusetts, eelgrass is most often found subtidally in shallow coastal waters. Eelgrass is subject to many anthropogenic and environmental stresses such as nutrient loading from storm-water run-off, pollution from oil spills, development related habitat loss, and climate change.
MarineFisheries staff have several ongoing eelgrass monitoring and restoration projects in Massachusetts. In addition, MarineFisheries chairs the Massachusetts Interagency Seagrass Group to bring together researchers and scientists working on seagrass projects in Massachusetts. For more on the Mass Seagrass Group and to see updates, pictures, and postings on seagrass go to our blog at SeagrassSoundings.blogspot.com
1. SeagrassNet Monitoring
The MarineFisheries seagrass monitoring program is part of SeagrassNet, a global monitoring program. MarineFisheries’ Salem Sound seagrass monitoring site is the 45th SeagrassNet site worldwide.
This monitoring program includes quarterly sampling of plant and habitat parameters to provide a baseline for the assessment of trends in seagrass habitat in Massachusetts and world wide. At our Salem Sound station we have defined three permanent transects at shallow, mid and deep water depths. Data collected include plant characteristics, such as percent cover, canopy height, biomass and distance to the bed edge; and environmental data, including light level, temperature, salinity and sediment grain size. Back at the lab, samples are processed and data entered into a web-based database.
Data collected from this effort will strengthen our understanding of the status and health of an important marine fisheries habitat, contributing to well-informed policy decisions and enabling effective responses to proposed coastal alteration projects impacting eelgrass.
All restoration methods used will be consistent with DMF’s Eelgrass Restoration and Monitoring Technical Guidelines document now available in the Technical Report Series or by clicking here
Boston Harbor Eelgrass Restoration
Eelgrass meadows were once abundant in Boston Harbor. Coastal development, severe organic loading from waste water treatment plants, and siltation in many areas of the inner and outer Harbor contributed to eelgrass loss for decades and by early the 2000s only a few isolated remnant beds remained. MarineFisheries restored eelgrass to Boston Harbor in a multi-year project involving planting and monitoring from 2004 to 2007. Eelgrass restoration served as partial mitigation for assumed impacts to marine resources from the HubLine gas pipeline construction which transits Boston Harbor. MarineFisheries biologists continue to monitor Long Island and Peddocks Island restored beds and in the summer of 2010 both areas showed expansion. Please see the HubLine Impact Assessment, Mitigation, and Restoration page for more detailed information about the 2004-2007 project.
In 2010 MarineFisheries began a second phase of restoration in Boston Harbor. A detailed site selection and test planting process is underway at several additional locations throughout Boston Harbor Islands. In 2012 MarineFisheries plans to plant restoration plots at Governor's Island Flats, Deer Island Flats, and Lovell's Island.
3. Collaborative Research
MarineFisheries routinely collaborates with state and federal agencies on projects involving eelgrass research and restoration.
The Eelgrass Resource of Southern New England and New York: Science in Support of Management and Restoration Success
A regional assessment of the genetic diversity of eelgrass throughout Southern New England tested against potential stress parameters to yield maps of eelgrass distribution and resilience.
Frederick T. Short, Ph.D., Department of Natural Resources and the Environment, UNH,
Anita S. Klein, Ph.D., Department of Biological Sciences, UNH
David M. Burdick, Ph.D., Department of Natural Resources and the Environment, UNH
Gregg E. Moore, Ph.D., Department of Biological Sciences, UNH
N. Tay Evans, M.S., Massachusetts Division of Fisheries, MA
Holly Bayley, B.S., Cape Cod National Seashore, MA
Stephen Granger, M.S., University of Rhode Island, RI
Christopher Pickerell, M.S., Cornell Cooperative Extension, NY
Jamie Vaudrey, Ph.D., University of Connecticut, CT
Conservation Mooring Projects
Eelgrass (Zostera marina) is declining at an alarming rate in Massachusetts due to a variety of anthropogenic stressors. Water quality impairment is the most commonly cited cause of this decline. However, boating impacts, such as damage from traditional mooring systems, also play a role in the loss of eelgrass extent.
Traditional block and chain moorings can create large circular scars in eelgrass beds due to the footprint of the block and the scouring action of the chain as it drags along the substrate.
For at least the past two decades impacts from mooring blocks and chain have been reported in the literature in seagrass systems around the globe (Walker et al 1989; Hastings et al 1995). More recently there has been a call to transition toward “seagrass friendly” moorings (Montefalcone et al. 2008 ), systems designed to minimize scour of seagrass beds with a helical anchor and floating, flexible rode. In Massachusetts, use of “seagrass friendly” or “conservation moorings” are rare and traditional moorings are still the norm.
MarineFisheries partnered with The Massachusetts Bays Program NEP, received a NOAA Habitat Restoration Grant with additional funding from the National Estuary Program and The Nature Conservancy. The objective of the project is to demonstrate the use of “conservation moorings” in two harbors in Massachusetts with a strong emphasis on outreach to boat owners and harbormasters. The primary objective of the study is to assess the ability of eelgrass to grow back into the scars left by traditional moorings after tackle is replaced with a “conservation mooring” system. After mooring tackle is replaced, the study will compare the rates of recovery in scars with and without eelgrass transplants.
The results of this project will have immediate management implications. Resource agencies are already recommending the use of “conservation moorings” and permitting agencies including the Army Corp of Engineers are re-writing mooring regulations with an emphasis on the use of this emerging technology.
4. Review of Coastal Alteration Projects
Projects should avoid impacts to eelgrass, a special aquatic site designated under the Clean Water Act Section 404.b(1). Consultation with MarineFisheries investigators is recommended if a project involves potential impacts to eelgrass or if a project requires eelgrass restoration or mitigation. Please see Technical Review for more information about MarineFisheries’ role in environmental review.
For more information, please refer to the following technical report:
TR-43 Evans, N. T., and A. S. Leschen. 2010. Technical guidelines for the delineation, restoration, and monitoring of eelgrass (Zostera marina) in Massachusetts coastal waters.
5. Rapid Site Assessments
Using video and acoustic methods, MarineFisheries is developing methods to quickly assess the health status and distribution of eelgrass beds.