BRUNSWICK

When eelgrass abounds it gets stuck in props and can be perceived simply as a navigational hazard, but healthy eelgrass beds are important to the ecological health of Casco Bay. This month, a new project is aiming to transplant eelgrass to local waters, in hopes of saving a habitat critical to fish, clams and lobsters.

On July 6, about 1,200 eelgrass plant shoots were collected from a healthy donor bed in Broad Cove off Cumberland Foreside, and the next day planted a couple hundred meters off shore at Simpson’s Point — just deep enough so the plants are covered at low tide so the plants stay permanently submerged yet shallow enough to get as much light as possible since the plants photosynthesize.

Much of the work going forward involves monitoring these plants for a full year. The greatest chance of failure is at the beginning of the planting, so the monitoring schedule is front-loaded, said scientist Hilary Neckles with the U.S. Geological Survey.

Neckles has presented on the project to many local stakeholders and says, “What’s great in our communities is there is a huge interest and investment in our coastal and marine resources. I find that people are passionate about preserving and restoring water quality.”

She stresses what a partnership this project is, involving so many organizations and falling under so many jurisdictions.

“This is all about learning,” she said.

From 2012 to 2013, upper Casco Bay experienced an extreme decline in eelgrass, a rooted seagrass plant. Eelgrass provides an incredibly important habitat for marine life — including commercial and recreation shellfish — according to Neckles.

The dense canopy of eelgrass provides protection for some species from predators, a refuge for juvenile lobsters and a nursery habitat for some fish and feeding ground for others.

It also provides food resources for birds, reduces water pollution by absorbing nutrients, improves water clarity, stabilizes shorelines and reduces coastal acidification.

Globally, the loss of seagrass is due to a host of causes, but declining water quality is primarily to blame.

A likely factor in the recent decline of eelgrass in Casco Bay was the explosion of the green crab population. As they dig into the sentiments to excavate their preferred prey, the crabs dig up and clip eelgrass, ripping the plants up to get to their food source.

During that green crab population explosion, more than half the eelgrass in Casco Bay was lost. Ground zero was in the upper bay, and nearly all of the eelgrass in Maquoit Bay was lost. Natural recovery is beginning in Freeport waters but upper Maquoit and Middle bays are largely still un-vegetated where the seed has to travel further.

The fact that there is natural eelgrass recovery taking place is an indicator that the green crab has declined in the upper part of Casco Bay at least. The bitter cold winter may have killed off the green crab which has historically knocked back population explosions. It could also be expected that the green crabs ate up too much of their own food source, Neckles said.

Neckles is the project manager for a one-year test project underway that will determine the feasibility of jump-starting eelgrass recovery in upper Casco Bay through restoration. According to the project plan, the loss of eelgrass is expected to “precipitate a range of impacts, including reduced fish and wildlife populations, degraded water quality, increased shoreline erosion, and reduced capacity to remove anthropogenic carbon dioxide emissions and mitigate coastal acidification. Therefore, reversing eelgrass loss in Casco Bay is of critical ecological importance.”

The information gathered will be used to inform larger scale decisions and whether or not this is something natural resources organizations want to take on, Neckles said.

Part of the project involves determining whether green crab control is required to restore eelgrass in Casco Bay as well as identifying successful eelgrass transplanting methods and environmental factors. Two sites were identified in upper Casco Bay for optimal transplantation of eelgrass. One test site is off Flying Point Road at the mouth of Maquoit Bay in Freeport. The second site is located of Simpson’s Point in Middle Bay in Brunswick.

Eelgrass has proven over the years to be a critical component to the intertidal areas and in particular, the soft shell clam population and density on the inside of the bays, Dan Devereaux said. It provides at high tide a buffering so that the clam seed stays inside the bay.

“Since I’ve been here, when eelgrass in our bays is flourishing, typically the clam population is flourishing as well,” said Devereaux, Brunswick’s marine resources officer and harbormaster.

Local shellfish harvesters in Brunswick are very aware of the butterfly effect, Devereaux said, and know if you lose one marine species, another is soon to follow if you don’t try to mitigate the loss.

“The town of Brunswick had been looking at eelgrass long before I came on board in the late ’80s, early ’90s back when they had dragging issues,” which is when harvesters really stepped up and became advocates for eelgrass, he said.

He believes the green crab traps monitored by Brunswick shellfish harvesters helped control the green crab population. Tons of the trapped crabs came out of the New Meadows River and Harraseeket River in 2011 and 2012. Shellfish harvesters saw a drastic decline in production last year and may see further decline this hump year because the clam seed that went into the mud this year hasn’t reached harvestable size, but the clam beds are very promising.

“We’re back on top of it now,” he said.

From Lower Flying Point to Merepoint Neck, the once bountiful lobsters are starting to come back, “and we’re wicked excited about it,” Devereaux said.

“Hopefully it’s a sign of good years down the road if we can keep our monitoring systems in place for green crabs and mitigate any type of warm spells that may introduce larger populations,” Devereaux said.

Plenty of project partners

THERE ARE SEVERAL project partners making this eelgrass restoration feasibility test project possible. It is a project of the U.S. Geological Survey, Casco Bay Estuary Partnership, Maine Department of Environmental Protection and The Nature Conservancy in Maine. Other partners include the town of Brunswick, Resource Access International, Friends of Casco Bay, U.S. Fish and Wildlife Service’s Gulf of Maine Program, Bowdoin College Environmental Studies, Southern Maine Community College and Citizens of Flying Point, Freeport. Also involved is expert seagrass restoration consultant Fred Short from the University of New Hampshire Jackson Estuaries Lab.