As marine experts and fishermen made clear at the Maine Fishermen’s Forum in Rockport recently, the ocean is changing and, with it, the coastal economy. Given the importance of fishing in Maine, particularly the lobster industry, the state needs to learn more not just about how increasing water temperatures are altering the biodiversity off its shores but how it can best adapt to and prepare for the changes.
For years, lobstermen and researchers have been reporting a shift in where lobsters are more likely to be caught. The changing population patterns correspond to changing ocean temperatures. As waters have warmed in the south, the lobsters’ habitable space has shifted up the coast. While Casco Bay once saw plentiful lobster colonies, Down East now looks like the next hotspot of Maine’s iconic fishery.
Rick Wahle, a research professor at the School of Marine Sciences at the University of Maine, studies young lobsters, which drift in the sea until they grow into “postlarvae” and settle down within rocks and boulders on the seafloor. The miniature lobsters won’t complete this important step in their growth cycle unless their new home is going to be warm enough. (They need warmer temperatures more than the adults.)
In the 1980s, researchers rarely found the little lobsters along the rocky bottom off the coast of eastern Maine, though they were plentiful farther down the coast, Wahle said. Now, there’s a surge of them Down East, as the waters have become just warm enough for their survival. There’s no doubt the ocean is changing.
The problem of course is that, if the pattern holds over time, lobsters will grow more plentiful in the Bay of Fundy and Canada and less plentiful in Maine. The state isn’t likely to stop the increasing ocean temperatures on its own. At the very least, it’s going to have to be prepared to anticipate changing conditions and adapt to the possibility of a new fishing reality.
The Gulf of Maine warmed about 1 degree over a period of 40 years prior to 2004. After that year, warming accelerated drastically, and there has been about a 1-degree increase every four years since, according to research published in the journal Oceanography. Since 2004, the surface temperatures of the Gulf of Maine have increased faster than 99.85 percent of the global ocean, said Andrew Pershing, associate professor at the University of Maine and chief scientific officer at the Gulf of Maine Research Institute.
How can Maine manage the lobster fishery more sustainably now to respond to the pressures from the changing sea?
First, it would help to know not just what has happened to Maine’s marine life but what will happen, especially with conditions changing so rapidly in recent years. That’s one reason to support the research of Pershing and others who are developing a way to predict how changing temperatures will affect fish and lobsters within a period of months, using modeling tools and data from NASA satellites and observing systems in the Gulf of Maine. The goal is to warn of unusual events in advance — like the 2012 lobster glut — and develop predictions for growth in different lobster zones or the upcoming mix of hard- and soft-shell lobsters.
Despite the importance of the industry, Maine still isn’t great at ecological forecasting. The need is apparent and could potentially lead to longer-term predictive models.
Maine also will have to prepare to accommodate the shifting boundaries of species in its management plans. And it will have to track the species moving northward, from south of Maine, such as black sea bass and squid, and determine whether and how they can become new economic opportunities for fishermen. The Department of Marine Resources is encouraging these kinds of discussions at regional meetings from now until April 1.
Maine is precariously dependent on lobsters, which is dangerous considering the Gulf of Maine’s lack of diversity. It used to have abundant cod, halibut, flounder, haddock, sea urchins, scallops and clams, all of which have been, or are being, depleted. Maine needs to get ready for the possibility that lobster could face a similar fate.