ROCKPORT — Lobster was the most valuable single seafood species harvested in the country between 2015 and 2018, according to NOAA, with Maine landings accounting for about 80 percent of that value in each of those years.
So it’s not surprising that the Maine Department of Marine Resources (DMR) invests a lot in lobster research. State scientists, in collaboration with academic and nonprofit institutions, have ongoing research projects to track the lobster population at different life stages.
Their data helps inform not only state fisheries regulations, but also a stock assessment used by the interstate Atlantic States Marine Fisheries Commission to inform the fishery management plan for the species.
As conditions in the Gulf of Maine change, some of the older research the assessment relies on needs to be updated. DMR scientist Jes Waller has been studying the size of female lobsters at maturity, when they begin to produce eggs.
The last such study was done between 1994 and 1998, Waller said in a presentation at the Maine Fishermen’s Forum. Updating that information was a research priority in the last stock assessment, she said. The new data will be considered in the next stock assessment, which is scheduled to be peer-reviewed this summer.
Fishermen have been observing “eggers,” female lobsters with eggs attached, that are smaller.
And sure enough, Waller’s work has found that in a research area between the Corea and the Canadian border, the average size of a female lobster when it begins producing eggs is down about two-tenths of an inch from 1995. The average size in 1995 was 3.7 inches, and today it’s 3.5 inches.
There are some regional differences: In the southern Maine research area from Friendship to the New Hampshire border, the average size in 1995 was 3.5 inches and today it’s 3.3 inches.
The center research area, Friendship to Corea, is scheduled for study this summer.
Early research on these smaller “eggers” in Atlantic Canada, Waller said, is suggesting that their eggs “may not be as high quality.” The Canadian researchers have found some evidence that eggs produced by the smaller females might have relatively less of the fats and proteins needed to successfully develop.
“Small females are more likely to carry what they call abnormal clutches,” too, Waller said. That means the tail is “not covered in eggs like it would normally be,” but only partially covered.
In Maine, research into this question of egg viability is just getting started.
“There are a couple people just starting to do this,” she said. “We’re waiting to see what those results will show us.”
Samplers collect a broad size range of female lobsters and bring them back to the lab for analysis. In the lab, they measure the carapace length, shell hardness, abdomen width and weight. They also note whether the lobster has been v-notched to label it as a reproducing female, and it’s “cull status” which means whether it’s missing a claw.
Fishermen interested in assisting with this project, or sharing observations, are encouraged to contact Waller at [email protected] or 350-6440.