
Picture by G. Danby
Along the coast of Maine, from the Piscataqua River to Passamaquoddy Bay, eelgrass populations are declining. What is eelgrass and why should we care? Eelgrass is a flowering marine plant that essentially defines the coast of Maine. It grows in thick beds that provide shelter to commercially important fish and shellfish species and other organisms that make up nearshore food webs. The underground stems and roots of the plant help to stabilize bottom sediments, thus preventing erosion and promoting water clarity.
As if that weren’t enough, eelgrass also acts as a carbon sink. In other words, eelgrass uses CO2 in the process of photosynthesis and stores carbon in the ocean sediment. In Maine alone, eelgrass meadows sequester approximately 51,000 (+/-14,000) tons of carbon dioxide a year, or the equivalent of the carbon dioxide emitted from approximately 10,000 cars annually. Thus, eelgrass plays an important role in reducing the impact of human-made carbon dioxide emissions and mitigating ocean acidification in Maine’s coastal waters. (…)
The Maine Commission to Study the Effects of Coastal and Ocean Acidification released a report on Feb. 5 recognizing the importance of shellfish resources and risks of ocean acidification to Maine’s economy. The commission made recommendations to the state of Maine regarding the threat of ocean acidification, and legislative members of the group introduced four bills to protect Maine’s marine ecosystem and coastal economy:
1) A bond proposal for a monitoring program to quantify acid from various inputs and chemical reactions affecting clam flats.
2) A measure to improve land for farming and implement best management practices for the watershed.
3) A measure to replace inadequate septic systems that impact nutrient loading and bacterial contamination of watersheds and bays.
4) A measure to continue the work of the ocean acidification commission.
We applaud this exciting development at the intersection of politics and the environment; however, a specific measure to protect and restore those habitats that are already absorbing CO2 from the water is missing.
Eelgrass can offset increasing CO2 levels from the atmosphere and absorb excess nutrients from polluted runoff, both of which can cause the acidity of the ocean to increase. So why not protect it?
A 2015 report on U.S. shellfisheries and ocean acidification by Julia Ekstrom and her colleagues in the journal Nature Climate Change ranks the Gulf of Maine third among regions in the United States most at risk for experiencing the devastating effects of rising ocean acidity. In recognition of the role of eelgrass in reducing ocean acidification, the Maine Commission to Study the Effects of Coastal and Ocean Acidification made the following recommendation: “Preserve, enhance, and manage a sustainable harvest of kelp, rockweed and native algae in bivalve areas and adjacent shoreline and preserve and enhance eelgrass beds.” (…)
Jane Disney, Bangor Daily News, 13 April 2015. Article.