Calm Lobsters Mean More Profit

by Laurie Schreiber

Dr. Jean Lavallee, Aquatic Sciences and Health Services, Canada, speaking at the Forum. “Death by a thousand cuts will start on the boat,” he said. “You’ll get more and more of those stressors and you get the snowball effect, and eventually you get to the point of no return, and that will be your dead lobster.” Mark Haskell photo

ROCKPORT—The way a lobster is handled—from the moment it’s hauled up from the deep and transported along its various way stations to the diner’s plate—can have a huge effect on its quality.

At the Maine Fishermen’s Forum in early March, Dr. Jean Lavallée, a Canadian lobster veterinarian and the region’s premiere lobster health expert, gave talk titled “Happy and Healthy Lobsters—Keep the Stress Down and The Profits Up.”

According to Lavallée, lobsters don’t like stress any more than humans do. But unlike humans, once a lobster feels stress, it has a hard time calming down. And its unique anatomy and physiology makes it far more susceptible to stress than humans. Because of its anatomy, traveling from the ocean floor to the boat, landing on another lobster in a crate, or simply resting in a barrel of water that is not cooled can be stressful. Too much stress can cause a lobster to become weak, injured or even die, he said. Handling practices and the holding environment can cause changes in the lobster’s physiological state and therefore put stress on the animal. Poor handling can also result in injury to the lobster such as a punctured abdomen, lost claws, cracked shells or broken legs.

“Just looking at the lobster is stressful for them,” he said.

One study looked at stress it relation to pot hauler speed. Two speeds were used, one a more leisurely pace of 80 feet per minute, the other standard commercial rate of 300 feet per minute. After measuring stress hormones, it was found those lobsters coming up faster were a lot more stressed, he said.

Handling causes stress, he said.

“Every time someone touches a lobster, a little bit of quality comes out of it,” he said. “As soon as they come out of water, their gills collapse and they won’t be able to breathe as well.”

Tank water that isn’t aerated is another problem. It might take about 20 minutes for standing tank water to lose all of its oxygen, causing the lobsters to hyperventilate.

Stress occurs during transport to the plant, with temperature changes by even a couple of degrees, and with toxicity.

“Lobsters are very sensitive to heavy metals,” he said. Copper pipes used to be more common. Lavallée recalled a time when a lobster fisherman contacted him to find out what was going on—he was losing 10 percent of his lobsters every day. It turned out the man’s tanks were fed with water coming through copper lines. While copper pipes are no as prevalent these days, he said, copper fittings are often found inside plastic lines, enough to leach copper into the water and make the lobsters sick.

Fresh water is a lobster’s bane, he said. Where lobster fishermen steam back to fill their tanks at ports that are at the mouths of rivers, it might not be apparent that a lot of fresh water is flowing on top of the seawater, he said. The lower salinity of the mixed water stresses the lobsters.

“They try to adapt to lower their salinity,” he said. “They drink a lot of water to try to dilute the salinity in their bodies. You’ll see the membranes bulging out.”

Then there’s behavioral stress, such as dropping a claw. There are different reasons for the lobster to do this, he said.

“What’s going on in the lobster’s head?” he said. “They’re looking at you and saying, A monster’s attacking me. I’ll drop a claw, and hopefully the monster will go after the claw and I’ll be able to escape. So when the lobster is dropping a claw, it’s telling you, I am very stressed.”

All of these factors add up to affect the ability of the animal to live long enough to make it to the plate, he said.

“Death by a thousand cuts will start on the boat,” he said. “You’ll get more and more of those stressors and you get the snowball effect, and eventually you get to the point of no return, and that will be your dead lobster.”

Whereas a stressed human bounces back in a short amount of time, he said, it can take weeks for a lobster’s stress hormones to return to normal levels.

“It’s very difficult to put the quality back it the tank once you take it out,” he said.

In the pot hauler study, it was found that the lobsters that came up at 300 feet per minute took 2-4 weeks before their stress hormones went down, he said. “It’s all the handling that’s happening at the boat, it’s all the handling at the wharf, and in the trucks, and in the plants, the wholesalers and processors,” he said. “Lobsters are touched by many, many hands before they reach the consumer, and every time they’re touched they lose a little bit of quality.”

The type of bait used can be another stressor: In one study, lobster fished with fresh mackerel were seven times more likely to arrive weak at the plant compared with lobsters fished with any other kind of bait, he said.

Also significant is tossing, as opposed to placing the lobster.

“Lobsters that are tossed are three times more likely to arrive weak at the plant than lobsters that were placed, he said. “That’s a no-brainer for me. If you’re going to be rough with your product and toss it around, it’s going to decrease the quality.”

Exposure to rain is another problem. Lobsters landed on rainy days were six times more likely to arrive weak at the plant than lobsters not landed on rainy days, he said.

“They don’t like fresh water,” he said. He advised keeping a tarp on the boat to cover product if it starts raining. When on the wharf, fishermen should not leave their crates exposed to the rain for long periods of time.

“So is it possible to maintain quality on the boat? Absolutely,” he said. “It’s also important to recognize not all lobsters are created equal. You can’t handle shedders the same way you handle hard-shell lobsters. It should be ‘one hand, one lobster.’ I don’t care if your hand is as big as a shovel and you can take 14 lobsters. I guarantee that as soon as you take more than one lobster, you’ll drop it on the deck. If you’re landing 8,000 pounds a day, even if you do ‘one hand, one lobster,’ you’re not going to go home any later. You’re going to go through all your catch in the same amount of time, because you’re not going to have to bend down every second time to pick up a lobster you dropped. And they’re not going to lose their claws. It’s going to make a huge difference.”