While the lobster fishery is king, the groundfish fishery in southwestern Nova Scotia is nothing to sneeze at.
This fishery is worth more than $55 million in landed value for 2016/17 for fishing areas 4VXW and Georges Bank and has solid stock statuses for primary target species such as halibut, haddock, silver hake, winter flounder and redfish.
“Halibut is the one that’s just going up and up and up,” said federal fisheries survey biologist Donald Clark in an interview.
“I really can’t think of anything negative to say about the biology of halibut right now.”
There’s also an abundance of haddock stocks, especially on Georges Bank.
“The abundance looks fine, but they just don’t grow the way they used to,” said Clark.
“The way they are growing has changed. Where haddock used to grow to 60 cm, now its rare to find haddock over 50 cm and that means if you take 10 cm off their length, your cutting their weight in half, so for the same number of haddock you get a lot less tonnage and that means although the abundance is really high, the quota is not as high as it might have been with this abundance because they don’t weigh as much.”
Clark said, in general, silver hake, redfish and winter flounder, which is a target species in the Bay of Fundy area “are all doing fine. The abundance is pretty good,” he said.
“Redfish, there’s lots and lots of redfish. Silver hake is much the same. We see lots of silver hake out there,” noting scientists are seeing silver hake up to 60 cm in recent surveys which are the biggest seen in the last 10 to 15 years.
“In around the mouth of the Bay of Fundy where we never used to see large silver hake we’re seeing some pretty large ones. When we started seeing them again we thought we haven’t seen them in a while then you start seeing them regularly, so you know things have changed. It’s not by chance.”
As for cod stocks, they look “awful,” said Clark. “There’s no way to sugar coat that. Cod abundance has been low for quite a while. Their survival is low, so they don’t get old, so you don’t see big ones around very much and it just ends up being a species that everybody is trying to avoid when they are out fishing.”
When asked why he thinks that species is not making a comeback, Clark said there’s a variety of possibilities.
“Their natural mortality is high. They don’t live long. The only thing we know that’s contributing to that is seals, but it seems unlikely that’s the only issue,” he said, adding their growth isn’t as good as it used to be either.
Cusk is also on scientist’s radar as a stock in trouble.
Clark said in terms of the overall productively of the ocean habitat in southwestern Nova Scotia, “how much fish we catch every year, it hasn’t gone down. What’s changed is which species are most abundant, so the productivity of the entire system still seems fine but it’s changing. Water temperatures have been really warm in some areas that we would have traditionally seen haddock and cod fishing, so around Browns Bank and the Fundian Channel the waters are quite warm and we’re seeing unusual species move into those areas, not in huge numbers but we’re seeing them regularly.”
Changes in available food sources also plays a factor in where species congregate.
“There’s a lot less calanus (which) is a small zooplankton really rich in fat and a favorite food item for things that like small stuff,” said Clark. “Food sources are changing. Everything is changing and as they change some things are quite happy with it and some are not.”
To better understand the stocks, Clarke said fisheries scientists are working on defining what sort of indicators of the eco-system status “we might use, what ones might be useful in telling us about the different aspects of the eco-system… to see if we can understand better why some (stocks) are doing pretty well and some are not doing well but are targeted by the same fishery.”
Bedford Institute of Oceanography scientist Alida Bundy has been leading some of that work in this region, said Clarke. While another scientist at St. Andrews is looking at “how we might divide up the entire area into chunks that might have some cohesiveness to the report on eco-system indicators so rather than mixing things together where we have different trends going on, she’s looking at how we might group things so we report how things are changing and be fairly consistent in each of the areas. So that’s a couple of things,” said Clark, noting feeding conditions and the condition of fish are among the eco-system factors that can be included directly into stock assessments and predicting what growth rates will be like.
