IMAGINE BEING labelled "one of the world’s most disastrous invasive species." Well, that’s what one 2004 report called the smallmouth bass. Over the last 20 years, the number of Nova Scotia’s lakes and rivers where they appear has more than doubled.
While bass are considered a sport fish, they are an invasive species whose growth comes at the expense of native species such as the brook trout, Nova Scotia’s provincial fish.
"When smallmouth bass are introduced into a water body, they prey heavily on smaller fish, can out-compete other fish species, and can become a dominant component of the food web," says a 2009 Fisheries and Oceans Canada report.
Unfortunately, legislation under the Federal Fisheries Act to prevent the spread of invasive fish species like smallmouth bass and chain pickerel has done little to help.
"There has not been a charge under this act anywhere in Canada since 1984," writes Steven Stewart, a spokesman for the Department of Fisheries and Aquaculture, in an email.
The biggest factor in the spread of smallmouth bass has been people introducing the fish into the province’s lakes and rivers. Under existing federal legislation, it is illegal to introduce fish into habitat without a licence.
But new legislation is giving anglers who are worried about brook trout some hope. In November, the provincial government announced amendments to its Fisheries and Coastal Resources Act which would give officers greater authority to enforce the provincial act.
"Officers would be able to fine people with live fish in their possession where previously an officer would have to witness an introduction before a charge could be laid," says Stewart. "That’s going to help protect our lakes and rivers."
The regulations are expected to take effect in the spring.
Lyle Goldberg, a past president of Trout Nova Scotia, is lukewarm in his support of the new regulations.
"It should have been dealt with 20 years ago," he says. "That’s the sad reality."
Goldberg says that catching people transporting fishing is going to be a challenge, "but it’s a step in the right direction."
The first introduction of smallmouth bass in Nova Scotia happened at Bunkers Lake in Yarmouth County in 1942.
"It was a sanctioned introduction by government to develop new recreational fisheries where traditional fisheries for speckled (brook) trout were diminished due to over harvesting, habitat alterations, poor land use practices, eutrophication and acidification," says a 2010 Fisheries and Oceans Canada report.
Since that first introduction, the number of occurrences in Nova Scotia’s lakes and rivers has grown to 188, according to Fisheries and Oceans Canada numbers, although some people believe that number is much higher.
While there have been a handful of sanctioned introductions, people have accelerated the spread by illegally transferring the fish from one body of water to another. The fish will then naturally disperse throughout a watershed, or all the lakes and rivers connected to the original body.
Why do people illegally introduce smallmouth bass into the province’s watersheds?
One reason is that some people mistakenly believe that trout may not be present in a lake because they are unable to catch them and will thus stock the lake with smallmouth bass. Gold-berg says because trout are a cold water species, they tend to go into deep water in the summer, making them hard to catch and leaving the impression they aren’t present.
Anglers also enjoy the challenge of fishing for smallmouth bass.
"From an angler’s perspective, they fight hard," says Eddie Halfyard, president of the Canadian Association of Smallmouth Anglers, a Nova Scotia-based organization which promotes fishing for smallmouth bass.
The time of the season is another factor.
"You can catch them for long extended periods of time, basically from April until nearly December, whereas things like brook trout and Atlantic salmon, they only have a select window of opportunity," says Halfyard.
You might think the situation would produce lots of conflict between trout anglers and bass anglers, but that’s not the case.
"I wear multiple hats on this," says Halfyard.
As a biologist, he is as well versed on the topic as anybody. He authored a 2010 Fisheries and Oceans Canada report on the options for "the containment, control and eradication of illegally introduced smallmouth bass."
Halfyard agrees that smallmouth bass are being painted as the bad guy.
"But it’s not unjustified," he says. "They are a fish that are very, very efficient at taking over a watershed.
"I appreciate and often side with the arguments that are put forward about the negative impacts of smallmouth bass and at the same time, it’s hard to deny the sporting qualities."
To help restore the trout population, Trout Nova Scotia would like to see barriers erected and watersheds reclaimed. The latter would be done by electro-seining, a process that Goldberg describes as using an electric wand to stun invasive fish species, which would then be removed from the waters.
There is no guarantee this process would work.
"You can do some reclamation if you do it within the first year or two probably (of an introduction), but if it’s beyond that, it’s a real challenge," says Goldberg.
Halfyard feels the emphasis should be on preventing the problem from getting any worse.
"The reality is there’s not a lot that can be done," he says.
"Once they’re here, they’re generally here to stay."
If invasive fish species continue to spread, it would be a loss on many grounds for trout.
"Trout represent the canary in the coal mine for healthy watersheds," says Goldberg. "If you have healthy wild trout populations, you have cool oxy-genated water with a healthy pH."
It would also be a cultural blow.
"We don’t want to see trout go the way of the salmon and the cod," says Goldberg. "It’s an historical and cultural fish. It’s our official fish and we want to see it protected because if we lost it, it would be a huge loss to the province."
Richard Woodbury is a writer and editor from Halifax.
ext
No comments:
Post a Comment