As the global focus on climate change shifts from negotiations in Paris to taking action to limit the globe’s average temperature increase, the focus is decidedly terrestrial. The text of the climate accord finalized last month isn’t exceedingly detailed when it comes to climate change mitigation strategies, but it devotes special attention to the importance of the world’s forests.
Meanwhile, there’s only one mention in the document’s 32 pages of a natural feature that covers 71 percent of the Earth’s surface, contains 97 percent of its water and produces at least half of its oxygen.
Oceans — which dissolve about a quarter of the world’s climate change-causing carbon dioxide — are key to any effort to combat climate change. And, of special importance to a coastal state such as Maine, oceans and the creatures that live in them are particularly susceptible to the consequences of climate change, from sea level rise to the increasing acidity of the world’s oceans.
There have been several reminders of that reality over the past year.
In April, a University of Rhode Island researcher shared findings that should be of special concern to those who depend on Maine’s lobster fishery for their livelihood. Maine, after all, has a dangerous dependence on lobsters; the iconic crustacean accounted for 78.1 percent of the value of Maine fisheries in 2014, an all-time high.
But the Gulf of Maine is warming faster than 99 percent of the world’s oceans and is becoming increasingly acidic as the water dissolves more and more carbon dioxide and other pollutants. The increased acidity makes it more difficult for lobsters to grow their shells, according to University of Rhode Island researcher Erin McLean, because it reduces the amount of available carbonate that they need to develop their shells. As lobsters strain to grow their shells, they have less energy to put toward their growth.
Juvenile lobsters with softer shells are more vulnerable to predators, meaning the phenomenon could lead to fewer lobsters making it to adulthood. Those that survive could grow into smaller adults, potentially detracting from their commercial appeal.
A year ago, a special legislative commission formed to study the effects of ocean acidification in Maine and recommend action sounded the alarm about potential danger ahead for crustaceans, shellfish, mollusks and other species that depend on carbonate to develop hard shells.
The 16-member commission said more research is needed to fully understand the effects of ocean acidification on commercial fisheries. The state needs to invest in its ocean monitoring and research capacity and act on what it already knows, the commission said in its final report, issued in January 2015. “The better the understanding of how acidification will impact commercially valuable species throughout their life stages, as well as the marine ecosystem as whole, the more prepared Maine will be to find effective and efficient solutions,” reads the document.
One way to act on what is already known is to take advantage of the ocean’s natural abilities to act as a “carbon sink.” Just as a forest absorbs carbon dioxide pollution on land, the ocean is home to seaweed and eelgrass species that can serve the same purpose — offsetting carbon dioxide pollution and making the ocean less acidic in the process.
Seaweed and eelgrass, then, could be key to lobsters’ survival and their future success. That means the state needs an effective management strategy to protect seaweed as harvesters take an increasing amount of it. Protecting existing eelgrass also needs to be a priority. And the state should encourage seaweed farming — an activity with a negative carbon footprint — by making it easier for entrepreneurs to secure the permission they need to set up seaweed aquaculture sites. (Seaweed is a nutritious food with the potential for market growth.)
The survival of Maine’s iconic fishery depends on an effective response to climate change and ocean acidification. As a result, the fate of Maine lobsters and seaweed could be inextricably linked.