During a night dive last week we noticed a number of brightly lit boats off shore and guessed they were fishing for squid. That’s exactly what they are according to the UT:
‘There’s been about 700 tons of squid caught in the last four nights,’ Gomes said. ‘You’ve got boats out there wrapping 50 to 60 tons each. With squid going for $800 a ton, do the math. They’re making out pretty well.’ Gomes said one squid boat actually had so many squid it rolled but didn’t sink. The crewmen managed to get the boat towed into Mission Bay.
700 tons. Wow. Hopefully the squid can get some mating in before they get caught. One thing we noticed was when the boats are out, there were a lot of loud explosion sounds that we could only hear at depth underwater. I’m assuming this is some sort of compressed air system to scare the sea lions off. Does anyone know?
Those explosion sounds were actually explosions. It turns out squid fishing boats use waterproof M-80’s called seal bombs to try to scare seals and sea lions out of the nets. From an article called “Squid fishermen’s seal bombs rattle nighttime scuba divers“:
Federal law allows commercial fishers and sportfishing charter boat operators to use seal bombs to ward off sea lions and harbor seals. Fishermen say the nonlethal explosives spare the animals from death or injuries that can occur if the marine mammals get entangled in their nets.
Experiences range from those who have been startled by the explosions to terrifying percussions from seal bombs detonated within a few feet of a diver, said dive master John H. Moore of San Diego.
While the seal bombs aren’t powerful enough to blow off a diver’s finger, the percussive sound waves could damage eardrums or sinuses, Moore said.
Kristine Barksy, a U.S. Fish and Game Department biologist who dives frequently, said sound waves are amplified under water and the percussion from seal bombs can be disorienting to an unsuspecting diver.
“You’re down at night. It’s all dark and then all of a sudden â€“ BOOM!” she said. “It’s very loud even if you’re not close.”
…Studies show that pinnipeds become conditioned to the noise from seal bombs, “which end up being like a dinner bell,” said Carrie Wilson, a Fish and Game Department spokeswoman. “It may help for a few minutes, but it’s not a long term deterrent by any means.”
Brockman believes commercial fishermen probably are using more seal bombs than ever because there seem to be more sea lions and seals trying to steal the fishermen’s catch.
Scuba divers would be wise to keep their distance when the squid fleet is working because the fishermen can’t tell whether divers are in the water at night
Uh, yeah. The seal bombs were loud enough a half mile away. I can’t imagine how crazy it would be in the water near a boat.