Squid have made a recent resurgence in Atlantic Canadian waters in what appears to be a little-understood boom and bust cycle.
According to Krista Baker, a research scientist at the Department of Fisheries and Oceans (DFO), the fluctuations in squid population have been well-noted for many years. She said that squid’s short lifespan of under a year, their highly migratory behaviour and their susceptibility to environmental factors seemed to have kept the population at low levels since the late 1970s to early 1980s, with a minor population boom in the 2000s.
“It’s really hard to pinpoint one or two environmental characteristics that kind of cause these large increases in abundance and then declines in abundance in such short timeframes,” said Baker.
“Their spawning areas are off the U.S., so there they’re going to be influenced in their spawning areas by things like bottom temperature, by productivity, salinity, large oceanographic conditions and then for us to see them in Canada, they move up with the Gulf Stream off of Nova Scotia. So, the Gulf Stream has to have certain characteristics that we would want it to have for them to be abundant and then they continue to move further north into the offshore of Newfoundland, and then when we see them in the inshore areas, it’s summer and fall. They’ll move into these inshore, warm areas in the pursuit of prey.”
After coming into the inshore areas off of Newfoundland to feed, squid will retreat back into the offshore and then migrate back to their spawning grounds off the Eastern United States.
According to Baker, this long journey that takes place in a small timeframe exposes the population to a variety of environmental factors that influence where and when people see them, as well as how abundant they are.
“If we see them — if the boom happens off Canada — then the environmental conditions off Canada have to be good, as well,” said Baker. “So, it’s kind of an accumulation of a lot of environmental factors that would cause this boom to happen in a given year, but what those specific environmental factors are is kind of still unknown.”
When all the right factors are in place to allow for an uptick in the squid population, they fill an important niche in the Atlantic Canadian food chain.
“A lot of predators depend on squid as an important source of food. A lot of pelagic and benthic fish eat squids, so things like dogfish, cod, turbot and others,” said Baker. “Marine mammals often eat a lot of squid, like pilot whales and also seabirds like gannets.”
In order to better understand the mysterious nature of how the squid populace rapidly grows and shrinks, DFO received $450,000 over three years for research initiatives in conjunction with fish harvesters.
“A lot of people, if they’re out fishing squid, they’ll notice new large signs that have gone up with surveys attached to them asking them to report their recreational catch,” said Baker. “So, there’s an app that they can download and basically complete a survey telling us how many squid they caught where they’re catching them and so on. A lot of people aren’t comfortable using an app, so we also have paper format distributed throughout Atlantic Canada, and they can simply fill out the survey, take a picture of it and email us or text it to us.”
Alongside the recreational survey program, DFO has recruited commercial index harvesters throughout Newfoundland to report their catch by way of a voluntary logbook.
“They’re saying where they’re fishing, how many they caught and they’re also collecting samples for us as well that will give us an idea of the size of the squid they’re catching, the maturity they’re catching and so on,” said Baker.
“Both parts of that research project are really to give us some basic information about squid because squid are so difficult to study. We’re looking at understanding — where are the high abundances of squid? When are they showing up and how does that pattern change from year to year?”
DFO is looking to get a better understanding of the genetics of squid, where they’re collecting samples from Florida all the way up to Newfoundland to understand some inconsistencies around where squid are spawning.
“All this time, we really assumed there’s just a spawning area off the U.S., but in recent years with this recent boom, we’ve had quite a few reports of mature females in our waters, which were very rare before. We hardly ever saw mature females,” said Baker. “We’re asking harvesters to take a photo if they see a female that has eggs and send it to us, and then secondly we’re doing this genetic study to look and see if some of these theories and assumptions we’ve had about the population are still true; that it is just one large population.”
