Scuba divers with the Ocean Protection Alliance have removed nearly all of an enormous “ghost net” off the coast of Southern California. The net had been killing sea lions, dolphins, sharks, and fish since a trawler sunk in 2006, as evidenced by the bones and carcasses on the ocean floor.
“Once you start cutting, visibility drops from 30 feet to zero because the water clouds up with particles and tiny creatures that get shaken loose,” said Cinde MacGugan, who led a team of divers to remove 200-sq-ft of netting. “At one point, I was frantically cutting off pieces of netting when one or more was tugged upward by an air bag.”
Due to the depth of the mission, the divers filled their tanks with a nitrous oxide mix in order to spend more time on the ocean floor cutting at the net. Without the nitrous, the divers would surely suffer decompression sickness.
While the group has removed over 800 square-feet of the net, it could take up to nine days to remove it in its entirety. The net is made of hemp and polypropylene and would stay intact for over 1,000 years if not removed.
“Worldwide, there are many thousands of derelict killer nets like this one, abandoned and adrift in the in the seas,” said marine biologist William Cooper, who was onboard the ship yesterday. “In one case, abandoned fishing gear in Puget Sound was studied for 10 years. An estimated 30,000 marine mammals, fish and birds were killed each year in it.”
Photo Credit: WikiMedia Commons under public domain
Your article is inaccurate these divers would not be using N2O Nitrous Oxide, they would be using Nitrox also called Oxygen Enriched Air or EANx.
N2O is “laughing gas” commonly used as an anesthetic if they had used this they would all have probably drowned, what they were using is called Nitrox.
Nitrox also called Enriched Air (EANx) is used to allow a diver to stay longer underwater but the higher O2 percentage means the diver must remain shallower to avoid Oxygen toxicity.
Normal Air is 21% Oxygen 78% Nitrogen and 1% other gases, when blending EANx you add Oxygen into the compressor or into the dive bottle to displace some of the Nitrogen.
I build and sell these types of systems for commercial diving, I have 30 years and 25000 dives worth of experience I highly recommend Nitrox for its safety but be sure to get the proper training before using it.
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