WC142 MayJune 2025 - Magazine - Page 30
CONSERVATION
Habitat On Ice
Winter habitat work bene昀椀ts Ontario’s walleye and lake trout populations
BY MONICA SEIDEL
EALTHY LAKES, RIVERS, CREEKS, and intermittent streams are the home to many of Canada’s
freshwater fish. Species like walleye (Sander vitreus)
and lake trout (Salvelinus namaycush) are top predators and ecosystem regulators. They are also top
sport fishing species that contribute to increased tourism
and community and cultural connections.
Despite their great importance culturally, ecologically,
and economically, Canada’s freshwater fish populations are
in decline. A 2022 publication found that out of 204 native
freshwater-dependent fish species in Canada evaluated for
their conservation status, 18.7 per cent of species were considered to be at risk. Populations of walleye and lake trout are
seeing declines from in-water factors like increased prevalence
of invasive species and fish pathogens, and a warming climate
that is leading to an expanded distribution of competing
warmwater species.
Their populations also face threats from human actions
taking place on land, like an increase of runoff flowing over
developed and hardened surfaces—think cottage driveways,
paths, and concrete retaining walls—which leads to increased
sediment deposited in a lake and the silting out of historic spawning beds. Walleye and lake trout are sensitive fish
species and siltation negatively affects their spawning beds.
For example, if walleye spawning beds are not cleaned by the
predominant wave action, or if too much algae and silt accumulate on the rocks, the walleye will not spawn there. Inputs
of silt onto the spawning bed can also cover eggs, preventing
them from being adequately oxygenated. This increases embryonic (early-stage development) mortality.
With many stresses threatening the future of fish populations, it is clear action must be taken to ensure these species
can thrive for generations to come. Perhaps surprisingly, a
favourable time of year to deliver restoration work benefiting
walleye and lake trout is during the coldest, darkest days of
H
Monica Seidel is the
Communications and
Fundraising Manager at
Watersheds Canada.
30
WATER C AN ADA • M AY/JUNE 2025
the year. Winter provides the perfect setting for spawning bed
enhancement work, as led by conservation leaders like Watersheds Canada.
A national registered charity headquartered in Eastern
Ontario, Watersheds Canada works alongside local community
groups, anglers, waterfront property owners, Indigenous communities, students, and municipalities to deliver restoration and
education programs that benefit Canada’s lakes, rivers, wetlands,
and shorelines and the species that live there. One direct way
Watersheds Canada is ensuring walleye and lake trout populations are able to thrive is through physically restoring their
historic spawning beds.
What exactly does this “habitat on ice” work look like? Just
a few months ago, Watersheds Canada undertook two such
projects to benefit native populations of walleye. All fish habitat
restoration projects begin with guidance from the Ontario Ministry of Natural Resources and knowledge sharing from local
community leaders. In the case of a walleye winter restoration
project that took place on Big Clear Lake, Ontario, Watersheds
Canada also worked alongside Big Clear Lake Association,
Shabot Obaadjiwan First Nation, and G.E. Matson and Sons
Construction, received support from Branch 334 of the Royal
Canadian Legion, and undertook the project thanks to funding
from the Government of Canada’s Environmental Damages
Fund. These fish habitat restorations are strong and successful
because of the diversity of partners involved and the wealth of
knowledge supporting their implementation.
After the initial discussions and establishment of solid local
partnerships, Watersheds Canada’s experienced habitat and stewardship staff lead the project planning. This part of the project is
vital and extensive, covering tasks like writing grant applications,
conducting in-person site visits, applying for necessary permits,
reviewing lake bathymetry maps, and corresponding with and
training all volunteers. This also includes assessing the feasibility
of delivering a winter project on a given lake. Not all lakes can
accommodate winter work due to water currents or the location
of the spawning bed.
When a winter project is deemed suitable, winter safety is a
major factor. Volunteers are coordinated to maintain a plowed
road atop the ice to facilitate easy travel to the habitat restoration
site, and to regularly monitor ice thickness to ensure motorized
vehicle traffic is safe as people and rock are transported to the site.
WAT E R C A N A D A . N E T
