LIVING LAB
12:34 pm
Wed July 18, 2012

Boom and Bust in New England's Lobster Industry

  • Heather Goldstone talks with Bob Seay about the science behind the lobster glut.

It’s been all over the news recently: there’s a glut of lobsters in the Gulf of Maine that’s driving prices down and hitting lobstermen where it hurts. I heard it first on NPR (Lobster Glut, Low Prices Leave Boats High And Dry), then read it in the Wall Street Journal (Lobster Glut Slams Prices). There’s even speculation as to whether Maine lobstermen are violating federal anti-trust regulations in efforts to push prices back up (Portland Press Herald: Are lobstermen keeping their traps shut?). The question is: what’s behind all those lobsters? I mean, when’s the last time you heard fishermen complaining about too many fish?

 

Downeast, lobster boom

It turns out there are a handful of factors at work in the Gulf of Maine:

Management practices: In the late 1980’s, fishery regulators instituted measures intended to ensure the long-term sustainability of New England’s lobster stocks by protecting the breeding population. Lobstermen can only keep lobsters whose bodies (tail excluded) are longer than 3 ¼ inches. The idea with a minimum size is to make sure lobstermen don’t pull all the animals out of the water before they have a chance to reproduce. 3 ¼ inches is just shy of the size where scientists think half of the females would be big enough to reproduce. In Maine, there’s an additional stipulation that lobsters with bodies longer than 5 inches also be let go – a measure intended to protect the largest, most productive breeders. And any egg-bearing females must be V-notched (a triangle is cut out of the tail to mark it) and released.

Ranching: As it turns out, lobster traps are extremely inefficient. One video survey suggested 9 out of 10 lobsters that enter a trap walk right back out after having a good snack. That has led to the idea that Maine lobstermen are “farming” or “ranching” lobsters.

Lack of predators: Large lobsters eat fish, of course. The inverse is also true: large fish actually eat small lobsters. Historically, groundfish – cod, haddock – are thought to have been a major predator of lobsters. But decades of intense fishing (often overfishing) have left groundfish populations in New England a shadow of what they once were. There are fewer fish, and the biggest ones aren’t as big as they used to be. That may be making it easier for juvenile lobsters to survive the gauntlet that leads to adulthood.

Rising temperatures: Ocean temperatures have risen 2-4F over the past several decades, thanks to global warming. In the cool waters of the Gulf of Maine, this increase may be boosting lobsters’ growth rates and contributing to the current boom. In addition, the warmer-than-average temperatures we’ve had over the past six or so months has prompted the arrival of soft-shelled lobsters (those are lobsters who have just traded their old, hard shell or a larger, softer version) nearly six weeks earlier than usual.

Add all these factors together and it’s not surprising that Maine lobstermen have seen steadily increasing harvests over the past few decades. Indeed, each of the past three years has set a record for Maine lobster harvests. The current glut is pushing prices through the basement and causing financial hardship for Maine lobstermen. The high density of lobsters in the Gulf of Maine also has some experts concerned that a disease could rip through the area and decimate the population. But I’m guessing those are problems southern New England lobstermen would love to have.
 

Down here, lobster bust

South and west of Cape Cod – Buzzards Bay, Narragansett Bay, Long Island Sound – the situation is distinctly different. There, water temperatures have historically been near the upper limit of what’s comfortable for lobsters. Global warming has pushed summer temperatures into the red zone, making lobsters more susceptible to disease and causing them to move away from important breeding and nursery grounds.

Warming, more acidic oceans threaten New England fisheries

Without a near-miraculous recovery, the southern New England lobster fishery could be nothing more than memory a decade from now. In that time frame, warming waters are likely to continue boosting more northerly lobsters. But if warming continues at current rates (if anything, it’s expected to accelerate), Gulf of Maine lobsters could eventually start to overheat as well.

Related program: