Studies Show Climate Change Could Cause Maine's Lobster Population To Crash

Oct 25, 2019

Two new studies of lobsters along the northeastern Atlantic coast look at possible reasons for the dramatic rise in the Gulf of Maine population beginning in the ’90s, and why those numbers could start to decline over the next several years.

Rick Wahle is a research professor at the University of Maine’s School of Marine Sciences, and an author of both studies. He told All Things Considered host Nora Flaherty that the findings aren’t new, but they strengthen predictions for the future.

This interview has been edited for clarity.

Wahle: In the Gulf of Maine, what we’ve seen is sort of the brighter side of climate change, if you will, in that the same warming that was going on in southern New England was actually bringing the Gulf of Maine and especially the eastern Gulf of Maine into more favorable temperatures for lobster settlement. And so as we projected into the future, we saw that there might be a boom coming, and in fact there was, into what were historically portions of the coastline that were too cold for settlement. And ultimately, that area explained the biggest part of the boom that really elevated our fishery to its current status as the most valuable fishery in the nation right now.

Flaherty: Are these studies showing that lobster decline is getting faster or is likely to accelerate over time?

Where we saw the biggest increases, we’re going to be seeing the big declines. But I want to hasten to say that we’re not going to be seeing a collapse by any measure. But you might think of this as a wave that has been cresting in our area in Maine, and especially eastern Maine, and is likely to be advancing into Atlantic Canada.

You and the other authors of this study are predicting that lobster landings over the next decade will return to levels that were the norm back in the late ’90s, early 2000s in the Gulf of Maine. What would that look like?

Well, so that would look like landings that are on the order of a quarter to a fifth the size of what we’ve been seeing in the past decade or so. It’s still unclear whether we’re going to see things fall to that extent. No one has a crystal ball here, and our survey only accounts for lobsters that we can sample in the shallowest band of the coast. And so if we’re not accounting for that expanded settlement into the deeper waters, where we can’t really quantify them effectively, we may be overstating the declines. And so that’s a cautionary note in these forecasts.

Maine lobstermen have certain conservation practices that they follow, like throwing back lobsters of a certain size and marking fertile females. How does this play into what you are presenting here?

Well, certainly it’s all-important to be protecting the broodstock, and Maine’s harvesters have really led the way in terms of being stewards of this fishery. We have some of the most conservative conservation measures. Having those measures in place can help offset the adverse effect of a warming climate, and forestall some of these declines we may be talking about. So yes, it’s all-important to be protecting that broodstock.