Researchers are trying to learn more about a unique species of fish found only in Lake Utopia in Charlotte County.
It’s called the Lake Utopia rainbow smelt, and is considered a threatened species.
Not only is it rare, it’s also very different, because it comes in two distinct sizes.
“It’s an interesting species because it has a large-bodied population and a small-bodied population that coexist,” said Danielle MacDonald, an aquatic science biologist for the Department of Fisheries and Oceans. “They’re known as a sympatric pair.”
Even though they are the same species, each size has its own habitat in the lake.
“Through an evolutionary process, although they’re the same species, they live in, well I don’t want to say different parts of the lake, but they utilize different streams,” explained MacDonald. “So they go into different streams to spawn. So they spawn discretely and they have different, they grow to different sizes.”
For the past two years, MacDonald has been looking in the streams that feed Lake Utopia, trying to find more of the smelt.
The fact they are only found in one lake got them listed under the Species at Risk Act.
“Because they are geographically, pretty much isolated in this particular lake,” said MacDonald. “So they’re in a very small area and the likelihood of them expanding into another area is not very strong.”
It’s illegal to fish the Lake Utopia rainbow smelt, but they still face natural predators.
“We were out here a few weeks ago and the eagles were sitting at the opening of this stream, so obviously the birds are quite happy to see the smelt come through,” said MacDonald.
Even small barriers in the streams, such as sticks and branches, can be an issue for them while spawning.
“Smelt are not known to be great swimmers or jumpers, so it’s difficult for them to be able to access their spawning habitat,” said MacDonald.
This year, MacDonald noticed significantly fewer spawning smelt than in 2015, which is why she isn’t having much luck finding many on her current trip.
But in the coming weeks, she and a scientist using sonar will be looking into deeper waters, following up on a population study done 10 years ago.
“They estimated that there are hundreds of thousands of the small-bodied population that are out in the lake,” she said. “But we don’t know a lot about what they do when they’re in the lake.”
Once more is known about the species including its population size an action plan for their risk management can be finalized by DFO.
2016 CBC/Radio-Canada