Stephanie Weinstein, senior lead on education for the Invasive Species Council of BC (ISCBC), along with other team members, has been busy this spring and summer connecting with Texada Island residents about a pair of special fish species only found in five small lakes on the Sunshine Coast.
What scientists call stickleback species pairs are found in four lakes on Texada Island, and one lake on Nelson Island. The spiny fish were also found on Vancouver and Lasqueti islands, but because of the introduction of invasive species they disappeared.
But why should residents living on Texada Island and the Sunshine Coast care about this pair of small spiny fishes?
Weinstein was excited to tell the Peak about the significance of the stickleback pairs, and the work ISCBC has done this summer on Texada, while raising awareness of the need to keep invasive species at bay.
"The stickleback species pairs consist of two types of fish in the same lake," said Weinstein. "One kind [benthic] that lives in vegetation in the shallow shorelines, and the one [limnetics] that live as adults in the deeper, open waters."
Weinstein said the stickleback have evolved in specific habitats in only a handful of lakes, so they may not be able to adapt to any changes that alter the lake habitat or food web.
"Invasive species are a primary threat to the stickleback species pairs, as are changes in lake water levels, water quality or water clarity," said Weinstein. "Because they are so localized, rare and vulnerable, the stickleback species pairs on Texada Island are designated as endangered by the Committee on the Status of Endangered Wildlife in Canada."
ISCBC stated on its website that the fish have been around for fewer than 13,000 years and evolved into two separate and distinct forms since the end of the last ice age. They are also valuable to scientists around the world who study evolution and biodiversity, said Weinstein.
One stickleback lives in open water and is small, sleek and spiny, while the other larger fish is camouflaged in the shallows of the lake.
"The stickleback species pairs contribute uniquely to global biodiversity found only on the Sunshine Coast," said Weinstein. "Because of their unique genetic history and their extremely limited distribution, they are considered invaluable to understanding a key question in biology: how do new species arise in nature?"
Weinstein said in the short time since they were discovered, two out of seven of the species went extinct.
"The introduction of the brown bullhead fish and crayfish have already caused the extinction of two populations of stickleback species pairs," said Weinstein. "Invasive species are a threat because once they are introduced they take over quickly and can impact their habitats in many ways."
BC has its fair share of invasive species, such as the goldfish and crayfish that rip up aquatic vegetation, causing increased turbidity, affecting nesting habitat for native species.
Weinstein said that the Himalayan blackberry, Himalayan balsam and knotweeds grow in dense thickets near waterways and they don’t hold the soil as well as native trees and shrubs.
ISCBC was on Texada doing community outreach during the sandcastle weekend in July and one big message its members were sending out was to the boating community. Not so surprisingly, boats spread invasive species.
"Whenever you take your boat, watercraft or gear out of a body of water, ensure to clean off all plants, animals, sand and mud that is attached," said Weinstein. "Drain all water onto dry land and pull any plugs. Dry all parts of your boat and gear completely before moving to another body of water."
Another message to the community was to never release any pets, live bait or plants into the natural landscapes or waterways.
"Many harmful invasive species were once pets or part of an aquarium habitat that were improperly and illegally released into the environment," said Weinstein. "We will continue to work with the community [on Texada] to develop meaningful resources and activities for youth and the public to appreciate and protect the stickleback species pairs and their habitat."
For more information on invasive species in the qathet region, go to bcinvasives.ca.
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