Off the hook
A council motion sets parameters for pots
in the Gulf of Alaska longline blackcod fishery
By Nick Rahaim
While serving as a deckhand on a longliner in the western Gulf of Alaska in 2013, my boat couldn’t shake a pod of sperm whales who gobbled up most of our catch. After working 20 hours a day for a week in a blustery March, I owed the boat money. As we moved east toward West Yakutat over the course of the spring, sperm whales were an on-again, off-again problem. We worked longer and harder to catch the same amount of fish. But the main casualty in the game of cat and mouse between our boat and the agile behemoths was our shared target — blackcod.
A move to allow pots in the Gulf of Alaska fishery is in response to sperm whales, as well as orcas, increasingly eating fish from longlines. Negative interactions between longliners and whales in the Gulf of Alaska have steadily increased for decades. Depredation — the act of whales eating from fishermen’s hooks — has caused fishermen much frustration and has cost them a lot of time and money. The phenomenon isn’t exclusive to the Gulf of Alaska. From Norway to the South Pacific, the Falkland Islands to Chile, fishermen increasingly find themselves competing with whales in hook and line fisheries.
The North Pacific Fishery Management Council moved in April to allow the use of pots in the Gulf of Alaska to harvest blackcod. The decision comes after years of review and strong support from various fishermen and industry associations. The motion was not without contention, however, with the Sitka-based Alaska Longline Fishermen’s Association opposing the change in gear type, asserting that it would hurt fishermen with small boats that couldn’t carry the large pots, thereby creating a new gear conflict.
Blackcod pots are heavy and fished with heavier line. “In conflicts between pot and longline gear, the longline gear will lose,” says the association’s March newsletter. “The longline gear is not strong enough, nor are the hydraulics on most longline boats sufficient to haul tangled pot gear to the surface.”
While ALFA is one of few industry associations opposing the move to pots, it was one of the first to take action when depredation started to increase. ALFA help found SEASWAP, the Southeast Alaska Sperm Whale Avoidance Project, a collaborative research organization that has been at the forefront of collecting data on sperm whales and depredation. SEASWAP has used hydrophones, genetic sampling and photo identification to better understand the phenomenon. They have also designed and tested deterrents, including decoys, buoys with playback devices, and bead gear designed to be acoustically confusing to whales.
But the association is up against the motion’s strong undertow. “I’m in favor of changing gear type,” said Justin Piecuch, captain of the Olympic, who has longlined since the early 1980s. “I don’t think the fishery can survive without that. Over the years I’ve noticed we have to run much more gear to catch our quota.”
While blackcod populations have trended down for most of the past decade, biologists with NOAA say declines are the result of low recruitment — spawning — and not depredation or overfishing. In the most comprehensive report on depredation to date, a 2008 study published in Marine Mammal Science found that depredation was “statically insignificant” and declared the average depredation rate to be 3 percent and 12 percent when whales were present. But the data was collected from 1998 to 2004, and since that time fishermen’s anecdotal evidence shows an increase in depredation.
“I strongly disagree with that number,” Piecuch said with a laugh. “Some whales are more skilled than other whales — some of them are determined to get as many fish as they can.”
Piecuch went on to say that when whales are particularly bad they gobble up as much as 90 percent of his catch. Granted, whales aren’t always present, but when they are, they’re much worse than the estimates. A report prepared by the North Pacific council for the April meeting stated “[e]stimates are generally conservative because it is not possible to attribute an empty hook (bait removed or disintegrated) to depredation.”
However, sperm whales have been known to pluck longlines by tugging on them with their jaws and releasing quickly, causing blackcod to fly off the hooks in the reverberation. In these cases, empty, undamaged hooks are all that’s left behind when a whale has stolen a snack, which can be difficult to document as depredation. The report prepared by the council also stated a reduction in depredation would make more biomass available for... » Read the full article in our JULY issue.
