No one is quite sure why but the Snow Crab population in the Bering Sea has dropped from an estimated 8 billion animals to abut 1 billion of the highly favored crustaceans. Diners are expected to go without as Alaska has suspended legal fishing this year.
According to Field and Stream magazine the drastic drop has occurred within the last five years.
There doesn’t appear to be a consensus about the cause. It is broadly agreed that there has been overfishing, illegal fishing and increased predation.
Some experts suspect “climate change.” That explanation is vigorously disputed.
According to the NOAA snow crab (chionoecetes opilio) is currently overfished but the agency says a rebuilding plan is in place. According to Alaska Fish Radio the language is confusing because the crabs are overfished but not subject to overfishing.
“However, the stock is “not subject to overfishing,” according to a report submitted to the North Pacific Fishery Management Council on the issue. That’s because the fishery removals aren’t above the level considered to be sustainable — rather, it’s because the stock dropped for other reasons that scientists and managers aren’t entirely sure of yet.”
It is broadly agreed that there has been overfishing, illegal fishing and increased predation. Population of cod and salmon have increased and they eat juvenile crabs.
According to the World Wildlife Federation illegal crab fishing is prevalent in Russian waters but is a concern woldwide.
“The US is likely importing large quantities of crab and other seafood which may have been illegally caught” said Michele Kuruc, WWF vice president of marine policy “The problem is the US is unable to say how much is illegal. We need a way to obtain and assess this information if we want to address this global illegal fishing problem.”
Predation is an issue as halibut, cod , salmon, seals, king crabs and other predators eat them. Reports of increased populations of some predators may indicate that is part of the issue.
The water in the region has warmed, but that is where the dispute sharpens. The opinion that “climate change ” is to blame is countered by the fact that the region is in a well understood La Nina pattern. The pattern is the strongest in a decade and may be pushing warmer waters north. Alaska has seen a warmer winter. Alaska News Source quoted climate specialist Rick Thoman:
“Nowadays we have very different conditions in the oceans than we had in past La Ninas,” Thoman said. “Bering Sea ice extent right now is extremely low and is going to stay that way for a little while at least, with all the storminess out there.”
Storms like the record-breaking low at the tail end of 2020 consistently churn the waters and eat away at the thin or young ice that does manage to form. This essentially leaves more open water and warmer temperatures along the western coast, despite a strong La Nina, Alaska News Source said.
It is worth noting that snow crab populations have crashed before in conjunction with La Nina events.
Meanwhile, in other puzzling oceanic news cold-water sharks have been found cruising in far warmer waters.