First published in Landings, January, 2013.
In welcoming more than one hundred top lobster scientists to Portland to take part in “American Lobster in a Changing Ecosystem: A US-Canada Science Symposium”at the end of November, Maine Department of Marine Resources Commissioner Patrick Keliher charged the crowd with helping managers and fishermen to define “the new normal.”
What became clear over the course of the four-day symposium, however, was that the present situation is anything but “normal,” and that fishermen have been helping scientists understand life beneath the waves for more than a century.
Fishing lobsters, it seems, could be viewed as a kind of grand, widespread, long-term monitoring program. As long as men and women have been dropping traps to the bottom of the sea and periodically pulling them up to the surface, they have been sampling the North Atlantic environment.
If the commercial harvest is viewed as a monitoring program, it isn’t coordinated in a way that serves as a diagnostic tool to warn of potential threats before problems become unmanageable—for example, to look for stress in the lobster population before pathogens infect it, or to grasp fully the effects of the North Atlantic’s changing climate.
The most obvious result of this sampling experiment we call lobstering is that there are a lot of lobsters in the Gulf of Maine. In his presentation, Dr. Robert Steneck credited the northern New England lobster bounty to an absence of large cod, the major predator of lobster. In some places, such as mid-coastal Maine, two lobsters can be found every square meter, the highest density on the planet.
Another thing all that trap hauling has helped show is that Maine’s lobster population has shifted two degrees north and east in the last fifty years, said Michael Fogarty of the National Marine Fisheries Service’s Northeast Fisheries Science Center in Woods Hole, Massachusetts.
Nearly half of the studies presented at the symposium used commercial landings data to identify trends in abundance. “The emerging story is one of climate warming, at once precipitating the lobster collapse in southern New England and promoting the historic population highs in the Gulf of Maine. And in a world of depleted groundfish predators and sound fishery management, lobsters in Maine have never had it so good. The big question is whether the calamities to the south move north,” said Dr. Richard Wahle of the University of Maine School of Marine Sciences and symposium co-chair.
“I think we have an interesting opportunity to understand what’s going on in the North Atlantic through this one animal,” said symposium co-chair and Maine Sea Grant Director Paul Anderson. But knowing the present and predicting the future are two different things. Of the factors that have been shown to have a relationship with lobster health and abundance, scientists can’t single out one as the most important. And they repeatedly told the symposium audience to expect surprises, instability, and complexity.
“Although there has been a great deal of research on the American lobster, and we know a good deal about its life history and perhaps how to manage its fishery, we don’t have the ability to predict its vulnerabilities to the changing ecosystem,” said Anderson. “If we simply assumed that the Gulf of Maine ecosystem will eventually degrade in a similar manner to what happened in Long Island Sound, then we’d also have to assume that the lobster population will be severely impacted. Now, although the Gulf of Maine ecosystem is changing, I don’t think there’s any evidence that it will change as markedly, or in the same fashion, as Long Island Sound. Nonetheless, the lobster is one of many canaries in this coal mine.”
The science presented at the symposium wasn’t just about lobsters, or canaries. It was about the coal mine. “We know so much about lobsters and there are so many of them. Lobster is a model organism to study ecosystems to inform management,” said Lew Incze of the University of Maine School of Marine Sciences.Category: Community Voices