Lobsters are more sensitive to the weather than the fishermen who catch them: fishermen are always on the water but the “bugs” aren’t always crawling.

Because fishermen are such efficient samplers of the lobster population, they are an excellent source of information on the dynamics of Maine’s most valuable crustacean. Last year the Island Institute, partnering with Anne Henshaw, a professor of anthropology at Bowdoin College, initiated an effort to understand the potential effects of climate change on the lobster fishery (WWF Nov. 2007). Preliminary analysis of interviews with over a dozen fishermen from up and down the coast reveals subtle shifts in lobster behavior related to storms, water temperature, and other weather and climate effects.

Fishermen report that the fishing season has been less predictable in the last six or seven years. Where they used to be able to count on the “shed” — when lobsters shed their shells and grow new ones — beginning in early summer, in the past few years it has varied from early spring to mid-summer. The season is definitely longer than it used to be and fishermen are setting their traps in August in places where they used to set them in October.

Longer-term trends are also apparent. In the 1960s and 1970s most fishing occurred inshore. In the 1980s, as the boom in landings began, the coves and harbors dried up and fishing moved offshore. Now inshore fishing is coming back in some areas but not in others.

How much of this is due to weather or climate? At this point, it is difficult to say because long term data on ocean temperature is limited and comparisons with fisheries dependent data such as landings is tricky.

Fishermen know that lobster activity is directly related to bottom temperature; some monitor bottom temperature as a guide to setting traps. They identify warming temperatures, increased storm activity and freshwater runoff — all indicators of climate change — as factors in the variability in lobster landings that they are encountering. The effects of storms hint at an interesting mystery. Fishermen report that fishing usually improves after a storm, especially in the fall — unless the storm is very severe in which case lobsters stop crawling altogether. We do know that climate change is likely to result in increased numbers and intensity of storms. Will the balance shift between helpful and harmful storms?

People who have been in the fishery for 25 years or more believe climate change represents another in a series of cyclical shifts, such as the variability in larval settlement, to which they must adapt. Their philosophy: prepare to weather a bad year (or two) of fishing.

Teasing out the effects of weather and climate is not straightforward. For example, fishermen tend to shift their traps into deeper water as the season progresses and lobsters shift toward warmer, deeper waters. But some are delaying the shift because of fuel costs; it’s more expensive to go further offshore. Others shift because of conflicts with yachts and other pleasure boats, which are thick inshore in August. Still others shift traps to avoid conflicts with scallop draggers. As a result, indications of when fishermen shift their traps are not simply a reflection of changes in bottom temperature.

Fishermen are also dealing with expensive fuel, the cost and availability of bait and low market prices. Excess effort in the fishery is a problem. Many fishermen are concerned about the effect of entry/exit ratios on the makeup of fishing communities in each of Maine’s lobster zones.

The Island Institute will hold a roundtable with lobstermen Feb. 27 in Rockland. Fishermen interested in discussing the effect of weather and climate on lobsters are being invited take part. The event is scheduled for the day before the Fishermen’s Forum, to allow fishermen attending the Forum to participate.

For more information contact Jen Litteral at the Island Institute 207-594-9209 or jlitteral@islandinstitute.org. Accommodations will be provided for the first six fishermen who respond. The findings of the roundtable will be presented at the Fishermen’s Forum, where there will be opportunities for further discussion at a session on Saturday morning, March 1.