At first, Pennisi was just trying to make nets lighter. It began when the California government passed regulations requiring fishermen to use small foot rope nets when trawling in shallow water. Foot ropes make up bottom edge of a trawl net. Because small foot rope nets take up less space, they are supposed to disturb less of the seafloor.
However, said Pennisi, small foot rope nets are less effective in deep water. The sea floor is soft and silty, and the foot ropes dig into the bottom and fill the net up with mud. “It gets in the fish’s gills and totally ruins the catch.”
There are a multitude of problems with traditional trawling nets, Pennisi explained. Pressure builds up at the “cod end” of the net, where the fish are held. This squishes and damages the fish. Trawls are indiscriminate, and bring in a lot of bycatch. Pennisi was catching fish that were too small and fish that were entirely the wrong kind.
“I would pull up a net and only be able to keep a quarter of my catch,” said Pennisi. “I’d sit there watching all of these fish die. It was a moral issue.”
To solve the problem, Pennisi set up shop in his back yard. He changed the mesh at the cod end of his nets to allow small fish to escape. He uses glowing ropes to scare away certain kinds of fish.
Pennisi has five different chambers he can attach to the cod end of his net. Each one is painstakingly designed to exclude certain kinds of fish. It is a labor of love.
“It’s costly,” Pennisi said. “I couldn’t even tell you how much money it’s cost me to build this. And it’s hard on the crew.”
When testing new designs, a lot of time is spent dropping the net, pulling it back in, watching videos, making modifications and dropping it again. They don’t make much money on those trips.
“Sometimes I have to pay the crew out of my own pocket,” Pennisi said.
Eventually, he partnered with the Environmental Defense Fund. They helped him finance some of his experiments.
“They kind of found me through word-of-mouth. ‘Hey, I know this crazy guy who keeps tinkering with his nets,’ ” Pennisi said with a laugh.
But Pennisi does more than tinker. He has a binder full of blueprints with different net modifications. He uses GoPro cameras attached all along his net to learn more about fish behavior.
“Different kinds of fish act in different ways once they’re in a net,” Pennisi explained.
He’s compiled dozens of hours of footage. Sometimes, he says, he falls asleep watching the videos on his laptop. “It drives my wife crazy.”
According to Pennisi, it’s worth it. Sometimes, he says, he only throws away less than 1 percent of his haul. The effect of his nets on the sea floor is more of a mystery.
That’s where James Lindholm, a researcher at CSUMB, comes in. Lindholm studies the ways fishing methods alter habitat. In a study published earlier this year, Lindholm analyzed the impacts of trawling on the sandy floor of Morro Bay.
Lindholm’s study used an ROV – a remotely operated vehicle – to take videos of the ocean floor before trawling, immediately after trawling, and one year later. The results were surprising. “We found that this type of gear, in this specific type of environment, may not have much effect on fish habitat in the long term,” he said.
The next step was to study the impacts of different types of gear, this time in Monterey. He would compare traditional small-foot-rope gear to light-touch gear, which is designed to have very little contact with the ocean floor. After he bounced his idea off various conservation organizations, the Environmental Defense Fund introduced him to Pennisi.
Like the study in Morro Bay, Lindholm’s research will span two years, and use an ROV to survey animal habitat before trawling, immediately after trawling, and one year later.
While Lindholm conducted his research, Pennisi was collecting his own data with his ever-present GoPros. He pulled up a video of a small-foot-rope trawl. The front edge of the net digs into the bottom of the ocean, pulling silt and bottom-dwelling animals, such as anemones, into the net.
“It’s basically shaving the seafloor,” Pennisi said.
Next, he played a video of a light-touch trawl net. The net appeared to float above the seafloor, barely touching the ground. It passed over anemones and crabs, and seemed to leave them unharmed.
Lindholm is hesitant to say that the light-touch net is better for fish habitat. He’ll know more next year.
“Data’s still coming in, and I’ve learned over time that the eye is deceptive,” Lindholm said. “But while we were out at sea … we all had a certain impression. I’m hopeful that we’ll have instructive results.”
Lindholm hopes his working relationship with Pennisi won’t end with the study. “Joe has tons of footage on his cameras. I’m working on a proposal right now to collect data from them.”