At the University of Maine, researchers believe they have found a better way to determine whether a lobster is fit for travel. Instead of testing serum protein levels in a lobster’s blood, they have developed a way to measure its grip.
Because dead, uncooked lobsters are inedible, lobster distributors want to make sure as many survive the trip as possible, in order to reduce their losses. Recently molted lobsters with soft shells tend to go to restaurants in Maine or New England or to processors while hardshell lobsters are shipped farther away.
Maine’s lobster fishery is by far the largest lobster fishery in the country and the largest commercial fishery in Maine. The fishery generated nearly $457 million in statewide gross fishing revenue in 2014 and, when factoring in other businesses that buy and sell lobster, is estimated to contribute more than $1 billion to the state’s economy each year.
About 30 years ago, Bob Bayer, head of UMaine’s lobster institute, and then-graduate student Dale Leavitt determined that the serum protein levels in a lobster’s blood was a good indicator of how physically robust the lobster was. The higher the serum levels of the lobster’s blood, the more time it spent hardening its shell since its last molt. The harder the shell, the more likely it would survive being packed in a box with other lobsters and would live to crawl around in the bottom of seafood market tanks in China or California.
Bayer said Tuesday that not every lobster is tested. Distributors take random samples of lobsters delivered by each fisherman and, if results from a particular group of lobsters seem to be good, they can be confident the entire batch will have a good shipping survival rate.
But according to Bayer the blood testing method is a little inefficient. Results are available in just a few seconds with the proper refraction analysis equipment, he said, but people doing the testing have to become adept at using a syringe and must constantly order new syringes in order to keep testing.
A couple of years ago, after getting a press inquiry about the strength of a lobster’s grip, Bayer approached UMaine mechanical engineering professor Michael “Mick” Peterson about developing a way to measure how hard a lobster can squeeze. Anyone who has been unlucky enough to get part of his or her body caught in a claw knows the appendage packs a lot of force, he said, but they wanted a way to scientifically measure it.
“It happened to me once,” Bayer said of getting pinched. “I had a few choice words to say about it.”
Peterson and Thomas McKay, a fourth-year mechanical engineering technology student, developed a pressure sensor that could fit in a lobster’s claw and then, with Bayer’s assistance, brought in a test subject. The first sensor, with grip points made out of hard plastic, turned out to be less fit than the lobster.
“That did not last long,” Matt Hodgkin, a UMaine senior who since has worked with Bayer on the project, said about the breakable prototype.
So a new sensor with an aluminum grip point was made, and it confirmed what many fishermen and other lobster handlers already knew: Lobsters can pinch — hard.
“We had one measurement of 70 pounds per square inch,” Hodgkin said Tuesday morning during a demonstration of the device at UMaine. Several people at the demonstration then tried squeezing the device with both hands but could only get a reading of about 35 pounds per square inch, or about half as much.
“We have to take an immediate reading,” Bayer said of each lobster’s initial squeeze, “because they lose interest [and let go].”
Under Bayer’s guidance, Hodgkin has spent a couple of years studying the results of claw pressure tests. When comparing them to the serum test results, they found a close correlation between each lobster’s serum level and the power of its grip. The more force it exerts when it clamps down, the higher the serum protein level is in its blood and the better its survival rate for long-distance shipping.
Hodgkin and Bayer said more research needs to be done to account for all the variables that may affect test results. Temperature, for example, seems to affect the power of a lobster’s grip but is not necessarily an indicator of how fit it is to travel.
Still, they said they know they are on to something and that testing lobsters’ health by drawing their blood may soon become a thing of the past. UMaine likely will not be the entity that develops lobster grip sensors for market, Bayer said, but the university would cooperate with any company that expresses an interest in doing so.
“This will be put out in the public domain,” Bayer said of the research project’s results.
©2015 the Bangor Daily News (Bangor, Maine) Distributed by Tribune Content Agency, LLC
