Thursday, May 30, 2013

Will the World Beat a Path to Your Door...?

If you build a better crab pot? (with apologies to Emerson)

Anne Arundel students build a better, or at least less problematic, crab trap
For years, environmentalists and watermen have been searching for a way to deal with the Chesapeake Bay's "ghost pots" — derelict crab traps that are too deep to retrieve and too problematic to co-exist with marine life. Though the traps have been abandoned, they continue to ensnare and kill crabs.

Now two Anne Arundel County high school seniors have developed a possible solution: a trap held together with zinc rings that decay, making abandoned traps fall apart at the bottom of the bay.
Crab traps become abandoned when they get separated from lines that tie them to buoys — propeller blades, harsh weather and other factors can cause them to separate from lines. They sink to the bay floor, where they endanger crabs and other species. With few viable ways to retrieve them, the traps have long been a bane of the crabbing industry, undermining yields for fishermen not only in Maryland but in crabbing regions worldwide
As part of an academic science competition, Andraka and Dana Lunkenheimer, 17, first attempted to come up with a trap that would come to the surface after nine months under water. But they decided that would be dangerous to boaters and swimmers, and abandoned the idea. Instead, they focused on making the traps fall apart.
Andraka, who lives in Crownsville, proposed creating a trap with rings made of zinc — a metal often used at the bottom of boats as a sacrificial anode, which decomposes to prevent the other metal surfaces from corroding.

The zinc rings would essentially dissolve in about eight months, he said, making the traps fall apart and lessening the risk to marine life. The students tested their hypothesis by attaching zinc rings to a steel plate and placing it in water from the Chesapeake. Over time the steel appeared pristine while the zinc significantly corroded. They didn't have a full eight-month period to test it, but were able to extrapolate that the rings wouldn't last beyond a normal crabbing season.
A pretty clever idea, really (although if you read the full article you get the impression that the solution may have been hinted at by a NOAA scientist).  However, I doubt if commercial fisherman will willingly pick up this design because it means you would essentially have to disassemble and reassemble the pots each season to replace the zinc rings that hold them together.  Not a huge problem if you only have the four pots a non commercial resident is allowed to use off their own dock; but an enormous chore and expense if you are fishing upwards of 1200 pots the way many commercial fishermen do.

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