Wilfred Meadus was met with quite a sight when he gutted a cod during the commercial fishery earlier this year.
Inside the stomach of the fish were many baby crabs, some whole, some not.
But it wasn't just one cod.
The inshore fisherman from St. Jones Within said about 25 per cent of his catch had a stomach full of baby snow crabs (also known as queen crab). In one fish he was able to identify 28-29 whole crabs and about a dozen more that were too small to identify.
"They were the crab we fish for."
Meadus has fished for cod for over 45 years. He also has a crab license and has fished for crab since the collapse of the cod fishery and resulting moratorium in 1992.
What struck Meadus as unusual about the incident was that so many cod had a large number of crab inside them.
"One cod had at least 30 to 35 crab inside."
Meauds said he worries that if this trend keeps up, the crab stocks will take a major hit.
"It'll destroy the crab fishery."
Meadus said the seal population, widely considered a threat to the cod industry, should now be viewed as an aid to the snow crab industry.
"One time, I'd shoot a seal so he wouldn't eat the cod. Now, I'd let him live."
The cod is definitely back, said Meadus, but at the expense of the inshore crab fishermen.
"If the cod keeps increasing there, there'll be no more crab to fish. If they're waiting for the cod to move offshore and eat the crab there, well, it's going to happen."
Meadus said the dollar value of crab and shrimp today needs to be compared with the value of cod.
"What's keeping the industry going today? With our cod abundance inshore and offshore, there will be no future for our crab and shrimp, if the cod keeps increasing. Some things add up and some things don't. Two and two add up to four but two and 'too' much cod add up to zero crab and shrimp."
Ocean climate variation, not cod,
a cause for worry
Earl Dawe is a research scientist with the Department of Fisheries and Oceans, specializing in offshore snow crab research.
He said cod is not a threat to snow crab, at least not in the offshore area. In fact, he says cod eating smaller crabs, rather than market size, is a good thing.
"If cod is going to impose a mortality on crabs by eating them, it's better that they eat them (when they are) little rather than after they survive all sources of mortality and (make it to recruitment size for) the fishery and then get eaten."
Dawe says mortality on anything in the water is highest at its youngest stages and probably less damaging on the overall crab stocks the younger the stage it happens.
Dawe said he could not speak specifically about the inshore because he doesn't study snow crab populations there
However, in the offshore, he says, there isn't much big fish, therefore not much snow crab is being eaten by cod. Before the moratorium, snow crab was historically a large part of the cod diet.
"Now, it's pretty much absent."
What is becoming very evident is that snow crab is most closely regulated by ocean climate variation, said Dawe.
Snow crab are very sensitive to temperature, and the critical stage at which ocean climate has a big effect on crab abundance is when the crab is bigger than the size found inside Meadus' cod, he said.
"Warmer waters are bad. Colder waters promote crab survival early in their life."
Since about 2007-2008 the snow crab resource in the northeast coast of the province (Labrador) is in decline, with both the inshore and offshore showing the same trend, said Dawe.
"Cod in the offshore are not eating the crab - I've got the data on that, I've looked at it. If they are eating crab in the inshore and if they're eating crab in the inshore in enough quantity to have an effect on their later recruitment, then why are the trends the same inshore as they are offshore? It doesn't make sense."
If predation by cod were a problem, the close relationship with temperature would not have been maintained long before the collapse of the cod fishery and long after, he said.
"In other words, you can't have several factors being the main factor. If there is a main factor, there's only one main factor. If predation comes into play then that will muddy up the relationship that we see with temperature."
Dawe is careful to mention snow crab predation by cod could still have a localized effect in some areas. However, it is probably not affecting the overall crab population, he said.
Furthermore, a high proportion of crab stop growing at a certain size and are too small to be fished commercially, and these crab are likely the ones cod are eating, said Dawe.
"There's a lot of crab eaten by cod that would never make it to the fishery anyway. If cod were eating great big crab, rather than little thumbnail (sized) crab, a year before they're going to molt and make it to the fishery, then that'd be a scary situation."