80% of N.L. snow crab are below fishable size
DFO warns fishing pressure could lead to long-term harm to stocks
Eighty per cent of the snow crab in the province's waters are now smaller than fishable size, and new biological research from the Department of Fisheries and Oceans says fishing pressure on the already strained stock is the main problem.
"There is a major biological concern here," said DFO biologist Darrell Mullowney.
Scientists say continuing to fish at high levels could lead to long-term serious harm to stocks through genetic change or impaired reproductive capacity.
The news comes just as the Department of Fisheries and Oceans is set to meet with harvesters about snow crab in a series of meetings being held across the province between November 19 and 29.
Mullowney said managers and scientists intend to be forthright at that meeting about the seriousness of the situation.
"There's a state of concern on this stock and, you know, the department is open in sharing the fact that we're concerned."
Not enough large crabs
The new research reveals that too many large male crabs have been removed from the population. When there are fewer large males, the smaller male crabs terminally molt — that is, they stop growing.
"[Small] crab used to have to grow large to compete with the larger individuals. In the absence of the larger individuals, there's no need for them to grow large anymore so they would sense that there's no big guys around anymore," he said.
The new research shows just how important large males are for the overall health of the snow crab population.
"[They] are superior breeders and do things like maintain the genetic hierarchy in the stock. So they're quite important," Mullowney said.
Potential long-term harm
Mullowney says fishers may be shocked by the DFO findings because it's not what they see when they haul in their pots.
"They're not allowed to use small mesh pots like we did, which can capture these undersized crabs, so they don't see this for the most part," he said.
They only see the big crab in the population. They do see that there's fewer and fewer in their pots, but they don't see the fact that 80 per cent of them are terminally molting and a small size."
There is a major biological concern here.- Darrell Mullowney
Mullowney is optimistic the situation can improve with the right management approach.
"If our interpretation of the situation is correct and this reflects the lack of competition from big males in the population, the answer is to reinstate some big males into the population," Mullowney said.
"That would mean at least a reduction in fishing to at least promote that process."
In fact, the DFO has supportive evidence for that approach from the province's south coast crab fishery. When fishing pressure was reduced there a few years back, size and maturity for the snow crabs started to increase. It took two-to-three years for the turnaround to occur.
Scientists are hopeful that the cause of the smaller crabs is situational, and not genetic.
"This is not irreversible harm or anything being done at this point that these things can't again grow large, and hopefully quite quickly, if we're able to re-establish a healthy population of big crabs," Mullowney said.
With files from The Broadcast