Restoring Nature’s Nurseries of the Sea

Posted on Sep 10, 2015

DSC02702In parts of Casco Bay, long blades of eelgrass still sway hypnotically in clear water, their tips just tickling the surface. It’s easy to imagine the multitudes of marine creatures hiding among the sheltering fronds.

At one time, the Bay had the largest and densest beds of eelgrass along the coast of Maine. In the mid-1990s, Casco Bay had approximately 8,700 acres of eelgrass beds. Today, nearly 60% of those beds have disappeared, mostly from Middle and Maquoit bays.

That is why Friends of Casco Bay Research Associate Mike Doan is excited to be helping with a project to replant eelgrass lost to marauding invasive green crabs. Mike is gathering critical data on water quality conditions at the replanting sites.

Restoring eelgrass benefits fish and wildlife populations. It also improves water quality, inhibits shoreline erosion, and removes nitrogen and carbon dioxide from seawater, reducing coastal acidification.

“Friends of Casco Bay is collaborating on a multi-organizational project to test the feasibility of restoring eelgrass to upper Casco Bay,” explains lead investigator Hilary Neckles of the US Geological Survey. Our Baykeeper boat picked up eelgrass harvested from a healthy site in Cumberland and transported it to Southern Maine Community College. There, volunteers cleaned and prepped the eelgrass for transplanting. The next morning, we delivered the shoots to the experimental site, where volunteers anchored the eelgrass using four different techniques.

The work complements our studies on coastal acidification. “It’s an exciting overlap with Friends of Casco Bay’s investigations of sediment pH in the area’s clam flats,” notes Dr. Neckles. “Mike is monitoring sediment pH of some intertidal flats that could be potential eelgrass restoration areas. This project will provide information about the role of eelgrass in mitigating coastal acidification.” She adds, “The results of our pilot project will inform decisions about the potential for large-scale restoration efforts in upper Casco Bay.”