Rockland- Thursday, March 5, 2015 was Shellfish Day at the Maine Fishermen’s Forum. Dozens of people showed up to hear academics, government representatives, and fishermen speak about the shellfish industry. Topics in the morning included red tides, economic losses from wastewater treatment plant closures, using technical and applied marine science Read more…
On January 22, eelgrass scientists and others interested in eelgrass conservation in Maine and New Hampshire came together to share work in progress and discuss future directions for eelgrass research and restoration in Maine. Six presenters covered topics ranging from eelgrass loss in Frenchman Bay, Casco Bay, Lamprey Bay, and Read more…
The Frenchman Bay Partners has been engaging community members in conversations about the benefits we all derive from our connections to Frenchman Bay. Last November, a series of workshops led to the development of an Ecosystem Services Value Decision Support Tool. The tool helps users identify and prioritize the attributes Read more…
Abstract: In 2013, there was a devastating loss of eelgrass (Zoestra marina) in upper Frenchman Bay, Mount Desert Island, Maine. This study examined the relationship between the most recent invasion of novel haplotypes of the European Green Crab (Carnicus maneas) and the decline of eelgrass in upper Frenchman Bay. While C. maneas is an invasive species that has been present in the Gulf of Maine for over 100 years, a second invasion of C. maneas in Nova Scotia occurred during the 1980s and 1990s, bringing novel haplotypes of the species that have been cited to be more cold tolerant and voracious as compared to other haplotypes. The presence of these new haplotypes has been hypothesized to be a contributing factor to habitat destruction along the Maine coast. In 2013, northern haplotypes of green crab were documented in upper Frenchman Bay where the eelgrass had disappeared. In order to assess this relationship, the cytochrome oxidase I (COI) haplotype of the crabs at sites around Mount Desert Island was determined as well as the abundance of the eelgrass at corresponding study sites. The study did not find a significant correlation between the presence of northern green crab haplotypes and eelgrass abundance at the study sites. This indicates that the status of eelgrass health is not dependent on the genetic composition of green crabs that are present. It is more likely that factors such as green crab abundance or water quality are contributing to the declining health of eelgrass beds along the Maine coast.
Alden Dirks, Swarthmore College
Abstract: Eelgrass (Zostera marina L.) supplies myriad ecosystem services that make it an indispensable cornerstone of coastal environments. The complete disappearance of eelgrass in upper Frenchman Bay, Mt. Desert Island (MDI), Maine, in 2013 matched a precipitous drop in the concentration of dissolved silica (DSi). Eelgrass in outer Frenchman Bay and other locations around MDI appeared to be intact; however there were no DSi data to compare with upper Frenchman Bay locations. To investigate the relationship between eelgrass health and DSi, we determined eelgrass abundance and biomass at six locations around MDI. Furthermore, we measured dissolved nutrient concentrations in the water column as well as tensile strength and nutrient composition of tissue samples. We found a positive relationship between eelgrass abundance and biomass, and a positive relationship between biomass and the concentration of nitrite and nitrate. In addition, tensile strength was significantly different across the six sample sites. However, neither abundance nor tensile strength was significantly correlated with nutrient composition of the plants or water quality. These results reveal a deeper complexity to the issue of eelgrass abundance and tensile strength that requires further nuanced investigation into other factors such as local geography, oceanographic currents, and sediment type as they relate to eelgrass viability.
The idea for Anecdata grew out of CEHL’s project at eelgrassinmaine.org, developed in summer 2013 as a way to enlist the broader public in documenting loss of eelgrass in upper Frenchman Bay and elsewhere in Maine. People up and down the coast reported — and continue to report — sightings of eelgrass and places where the plant was lost. During that time, the lab was also receiving reports from the public about changes in organisms and habitats other than eelgrass. A place to put that information was needed, and a grant from Long Cove Foundation allowed Bailey to spend the winter building a larger, more robust data portal where emerging trends could be documented.
Everyone has been hearing a lot about green crabs and their destructive nature these days. Frenchman Bay definitely has its share of them. Green crabs are an invasive species from Europe that were unintentionally introduced to the Eastern shores of America in the 1800s. Their numbers have been increasing ever since.
Maine Sea Grant sponsored a Green Crab Summit at University of Maine in December 2013. Many Frenchman Bay Partners were in attendance. The presentations provided a lot of detail about green crabs, their life history, and their impacts on shellfish populations and as well as salt marshes and seagrass beds. They can be viewed at http://www.seagrant.umaine.edu/green-crab-summit. Several Frenchman Bay Partners, including representatives of the Bar Harbor Shellfish Committee, MDI Bio Lab, and Frenchman Bay Regional Shellfish Committee participated in a one-day, state-wide survey of green crabs last summer, focusing their sampling efforts in Bar Harbor, Lamoine, Trenton, Sorrento and Sullivan. The results of the survey can be found on the Maine DMR website . The report concludes that green crabs are present throughout the state and in numbers that represent a detrimental impact to bivalve shellfish.
The U.S. Army Corps of Engineers has awarded the Mount Desert Island Bio Lab a grant of $239,000 for eelgrass restoration in Frenchman Bay. The grant will enable the Lab and its partners to restore an additional 214 acres of subtidal habitat off Lamoine, Bar Harbor, and Trenton over the Read more…
During the summer of 2013, a group from Mount Desert Island Biological Laboratory and Southern Maine Community College began a benthic survey of numerous sites in Frenchman Bay. The survey was undertaken to compare current benthic species diversity with historical records collected during the first half of the 20th century. Read more…
The Frenchman Bay Partners’ plan of restoring an additional 228 acres of eelgrass this summer had to be put on hold when it became clear that eelgrass was not coming back in the restoration areas that had been thriving for years. Not only that, many formerly healthy beds that had been growing at least since mapping began in 1996 were also lost this year. MDIBL’s Community Environmental Health Lab (CEHL) had to quickly change gears to begin studies on possible causes of the loss. Scientists and interns looked into the possibilities of “wasting disease” (the pathogen Labyrinthula zosterae) which caused devastation to the plant in the 1930s, nutrient deficiency in the sediment, temperature changes, and invasive green crabs. (more…)