Some Maine fishermen lament the small amount of northern shrimp (pandalas borealis) they are allowed to catch in 2013, and are critical of the science behind the regulations. However, historical data and rising sea temperatures indicate a real threat to the survival of the species.

Lobsterman Steve Peaslee, who for the past few years has hauled his 200 shrimp traps out of Sheepscot Bay, is concerned about the future of this industry. He joined a room full of fishermen, processors and other industry professionals at a meeting with the Atlantic States Marine Fisheries Commission Northern Shrimp Section in Portland December 3. 

“We've got to do something,” he said in response to the scientific data. “These numbers are declining. I've got a young boy coming up in the ranks and I'd like to see a future for him.” 

Peaslee said there are a lot of uncertainties between what fishermen have experienced first-hand and what scientists say about the health of the shrimp fishery. But if the data is true, he said he realizes changes will have to occur in order to sustain the fishery.

The Section's Technical Committee issued a 2012 northern shrimp stock assessment, which was presented to fishermen and commission members during the meeting in Portland. The report (available at www.asmfc.org) was presented by Technical Committee member Ann Richard from the University of Maryland's Chesapeake Biological Lab. It showed trawl surveys conducted off the Maine, New Hampshire and Massachusetts coasts, some of which took place last spring and summer.

The report states there was concern that surveys taken over the past few years were not adequately tracking the shrimp. But one possible explanation, that shrimp were migrating into cooler ocean pockets, was rejected after previous year surveys suggested no such trend.  

The 81-page report demonstrates an extensive body of research was conducted by scientists to illustrate the fishery's condition. It includes: comparisons of current data to survey results dating back over the past 40 years; commercial landings over time; biological sampling; size, age and condition of shrimp; the yield of new juvenile shrimp entering the fishery and a lot of other information.  

One conclusion the report makes is warmer water temperatures are likely to be the blame for the steep decline in shrimp populations in January and February of 2012. 

Subsurface temperatures measured in shrimp habitats this year were “highest on record” and surface temperatures measured in Boothbay Harbor show a warming trend close to highs seen during the 1950s, when shrimp populations dropped dramatically. 

According to a chart, the entire New England fishery saw just 2.2 metric tons of northern shrimp, 100 percent of which was caught in Maine, in 1958. In 1965, the fishery's total landings climbed to over 900 metric tons and by 1969, landings reached a peak of just under 11,000 metric tons. Commercial landings have not been nearly as high since and water temperatures have been increasing.

“The environment is hot; it's warming and it's reached levels that are warmest on record,” Richard said in her presentation to section members. 

Data from multiple studies indicates the shrimp are adversely affected by temperature change.

In late fall to early winter, female shrimp migrate inshore to hatch their eggs.  Once they do, these shrimp are vulnerable and more susceptible to death, but at 3 1/2 years, they can still reproduce. The female shrimp are larger; they are also the targeted species in the shrimp fishing industry.

Richard said warmer temperatures have led to earlier hatching. Also, harvested shrimp have been getting smaller and the number of all sizes of shrimp has dropped. 

“We hope that we'll have a cold winter,” Richard said, nearing the end of the committee's report. “But that remains to be seen.”

The Technical Committee did not get what they asked for: a moratorium on commercial shrimp fishing in 2013. The reason for the moratorium was to increase the possibility that more shrimp eggs would be hatched. 

“We see that survival conditions for those larvae are going to be poor,” Richard said. “So the more you put out there, the more you are going to have survive.”

Before the section voted for a limited season, the committee recommended fishermen harvest only the five-year-old female shrimp that have already hatched their brood. That strategy would be as close to a “no-harm fishery” as the New England states could get, Richard said. In order to do this, the season would have had to start around February 15.

Such a late start date could pose problems for fishermen who cast trawling nets, who have said the shrimp are gone by February 1. However, trap fishermen like Peaslee could benefit from a later start date if the science is true and hatching is occurring later.