Eelgrass Restoration

Preparing eelgrass gridsEelgrass (Zostera marina) is a flowering plant occurring in widespread meadows in sub-tidal areas along the coast of Maine. Eelgrass beds provide habitat for a diversity of marine organisms, and serve as a nursery for a variety of juvenile fish including winter flounder, hake, pollock, and cod, as well as larval lobsters, mussels, and crabs.

Eelgrass also curbs erosion by stabilizing bottom sediments and improves water quality by absorbing excess nutrients from runoff. In Frenchman Bay, eelgrass  experienced significant declines over the last couple of decades. At Hadley Point the bottom coverage was estimated at 60-80% coverage in 1996, based on aerial photographs taken by the Maine Department of Marine Resources. By 2007, our pre-project underwater videography revealed that the coverage was down to <1%.

Dragging for mussels and other sessile species may have contributed to eelgrass loss between 1996 and 2007. Since then, local mussel harvesters have helped to establish “no drag zones” in upper Frenchman Bay, making restoration possible.

A variety of community partners and individual volunteers have contributed to the restoration of eelgrass at Hadley Point and other nearby sites over the last eight summers. Thousands of plants have been moved to upper Frenchman Bay from less depleted areas. A variety of transplant methods have been used with success. Eelgrass transplants spread by rhizomes in the months and years following transplantation. After the first year plants produce flowering shoots and distribute seeds in the restoration site and surrounding areas.

Despite the reduction in dragging, eelgrass completely collapsed in upper Frenchman Bay in summer 2012, possibly due to record high water temperatures in the Gulf of Maine combined with changing nutrient regimes and an explosion of destructive green crab populations in the bay. Although there was a complete lack of eelgrass in upper Frenchman Bay in 2013, seedlings sprouted in restored eelgrass areas at the end of summer 2014.

Most important in the long run may be the results of our public outreach and education programs. Local students have contributed to restoration and monitoring, learning that it requires a lot of work to restore habitat once it has been destroyed. Citizens from Bar Harbor, Lamoine, and Trenton have participated in mapping eelgrass in the upper bay. In addition, we have educated hundreds of visitors to the MDI Biological Laboratory about the importance of eelgrass as habitat in subtidal areas of Frenchman Bay.

Seagrasses in Classes

aquariumSeagrasses in Classes is an academic year education program in five Mount Desert Island region middle schools and two inland high schools. The program is a school-year extension of the MDI Biological Laboratory’s efforts to restore and study eelgrass beds in upper Frenchman Bay.

Students from participating schools use eelgrass aquaria as the basis for small inquiry-based research projects. CEHL Director, Dr. Jane Disney visits classrooms on a regular basis to help students with tank maintenance and guide them through the process of scientific inquiry. Teacher and student resources, activities, and links to data and information can be found at the Seagrasses in Classes website.

The program culminates annually with the MDI Biological Laboratory Student Marine Science Symposium, where students share the results of their classroom-based eelgrass projects.

Participating schools:

  1. Tremont Consolidated School
  2. Pemetic Elementary School, Southwest Harbor
  3. Mount Desert Elementary School
  4. Connors Emerson School, Bar Harbor
  5. Lamoine Elementary School
  6. Bangor High School
  7. Waterville Senior High School