Eight, in this case, is a fascinating number. As in, $11,938 or, also, as in eight per cent. Wednesday, the provincial Department of Fisheries and Aquaculture announced it was offering up $11,938 to the Centre for Fisheries Innovation to run an experimental side-scan sonar program.
The program will involve towing an underwater sonar unit to send up an image of a relatively wide swath of the sea floor, in this case, to see if the technology can be used to find lost crab pots. Some pots are lost every year through the failure of their buoys or ropes; others are lost in gear conflicts with other vessels or are cut free or towed away by ice.
And that’s where the other eight comes in: the province, in announcing the funding, points out that “eight per cent of snow crab pots are lost at sea annually.”
The pots would, pretty quickly, lose all their bait, and that would certainly cut down on the number of crab likely to stumble through their inescapable plastic collars. But their ability to continue to catch crab unwary enough to crawl over — and into — their top-openings would continue.
As a crab-catching technology, they’d still work pretty much the way they were designed to work — unless they were crushed by other fishing gear, or completely torn up by storm action.
That being said, you don’t see many crab pots washing ashore broken up, the way you see lobster pots after a storm.
Crab that then die in the traps might end up being their own form of “ghost fishing” bait; there isn’t a lot of information around about the fishing efficacy of lost or abandoned crab gear. But one thing’s for sure: all in all, it’s a lot of gear to have lying around down there.
Think of what an eight per cent annual gear loss really means: the crab fishery has been chugging along relatively strongly since a few years after the cod moratorium, some 20 years ago. With an eight per cent annual loss, that means the crab fleet essentially loses its entire inventory of crab pots on the bottom over a span of 12.5 years. Over 25 years, that would mean there’d be close to twice as many lost pots on the bottom as there are working pots being hauled by fishermen.
And, unlike ghost nets that get balled up and torn in storms — and occasionally thrown ashore with all manner of marine life caught up in them — a properly set crab pot could stay in one place for a pretty long time.
Add to that the fact that they are relatively structurally sound; metal or mesh crab pots are unlikely to break down quickly underwater, though they probably grow weed skirts pretty fast. (Some change will come in the 2013 season, when DFO will require crab pots to have biodegradable twine.)
Finding the pots might be a valuable effort. Better still, if we can understand why so many get lost by recovering and examining some of the stray gear, we might be able to figure out ways to lose far fewer of them. And that would suit everybody involved.