Two local streams, Flanders Stream in Sullivan and the Somes Brook drainage that includes Long Pond and Somes Pond on MDI, have been the focus of local restoration efforts over the past several years. Newly released Maine DMR reports from volunteer counts for both rivers in 2014 showed migrating alewives similar to 2013, which was a banner year on MDI and a strong initial year after a restoration on Flanders Stream. For this report I wanted to focus on the Flanders Stream work and subsequent report written by Claire Enterline of the Maine Department of Marine Resources. We will update work on the Somesville fish run in a future report, although you can see the document written by Ms. Enterline here.
Conservation Action Planning Mudflat Progress
The Frenchman Bay Partners (hereafter Partners) are a diverse group of people who help organizations in the watershed work together for ecosystem health and marine-based livelihoods. The Frenchman Bay Regional Shellfish Committee (hereafter Shellfish Committee) formed in 2009 in response to widespread red-tide closures to manage the intertidal mudflat resources in the 7 towns in the ordinance. The respective missions of two organizations address the long-term stewardship of the region’s resources. The two groups have been working together since 2011.
New Eelgrass Restoration Methods Trialed
The Community Environmental Health Laboratory (CEHL) tried four new methods of restoring eelgrass this past summer. The season began with the tried and true method of tying eelgrass plants onto wooden, biodegradable grids strung with twine. The up front time required to construct the grids with string and make ties from floral tape prompted the development of further prototypes. We next tried weaving plants through pieces of burlap stretched across the same biodegradable grids. We quickly realized the time required to weave eelgrass into the burlap on shore was too much. At the scale CEHL hoped to restore, both the string and the burlap grid methods necessitated too much time and effort.
Students in the Young Environmental Leaders Program created a burlap “restoration runner” weighted with sandbags. Eelgrass was woven into the seven foot long runners. Another method involved tying eelgrass onto metal washers, which were dropped from the boat into the water at the restoration site. In an effort to move away from the potential environmental impact of metal washers and decrease the cost of restoration, CEHL tried using rocks instead of washers.
To date, we have used frames with eelgrass tied to strings, frames with eelgrass woven into burlap, burlap without frames with eelgrass woven in, eelgrass tied to washers, and eelgrass tied to rocks. We are working on a seeding method. Seeding plants have been collected and are maturing in a flow-through seawater tank. Eelgrass restoration methods will continue to evolve as different challenges arise.
Population Genetics of the Invasive European Green Crab, Carcinus maneas and its Role in Eelgrass Loss in the Gulf of Maine
Mary Badger, Smith College
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.
Eelgrass (Zostera marina L.) loss in Maine: An investigation into possible causes
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.
Anecdata: Collecting observations of a changing world
MDIBL’s Community Environmental Health Lab (CEHL) rolled out its new crowd-sourced mapping tool and nature journal, Andecdata, at the Acadia National Park Science Symposium April 16. The website at www.anecdata.org is a repository for students, citizen scientists and community members to report observations of our changing environment. These reports are displayed on an interactive map and can help reveal trends, inform restoration and resource management efforts, and give users a broader understanding of their environment and the changes that are occurring due to climate change and other factors.
Green Crabs in Frenchman Bay: The Continuing Saga
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.
Population Genetics of Invasive Green Crab
Click here to access an academic poster by Bates College student Camilla Nivison, and advisors Larissa Williams and William Ambrose detailing the population genetics of invasive green crab, Carcinus maenas, in the Gulf of Maine.
One of the most successful marine invaders, Carcinus maenas has established populations on all temperate coasts. The past few years have seen a surge in the abundance of C. maenas and their impacts on coastal communities from Long Island to Nova Scotia, which may reflect a new strain of C. maenas introduced into the region from Northern Europe. As a marker of genetic diversity and gene flow between populations, I studied haplotypes caused by silent mutations of the mitochondrial cytochrome c oxidase I (COI) gene. I found the highest genetic diversity in the northern sites (NS: h=0.7619). Pairwise comparisons show Nova Scotia and Mt. Desert populations are genetically more differentiated from the other populations (NS: FST=0.4201 , MDI: FST=0.1448) likely caused by the recent invasion to Nova Scotia, which has subsequently spread south.
Call for Submissions
Hello Frenchman Bay Partners! The April e-newsletter is being put together as we speak. If any partners have news to share, updates, upcoming events, photos, or articles you want to be included, email Anna Farrell at email@example.com by noon April 18, 2014. The newsletter is sent to all members, so it’s a great way to get the word out!
A Climate of Change: Warming Waters in the Gulf of Maine
You can find the full workshop report here on the Island Institute website.