| Carp
Barriers In Frenchman’s Bay Since its introduction, as a means to
enhance the sport fishing industry, the Common Carp has spread throughout
North America into nearly every type of waterway. This non-native species
is a threat to wetlands in Ontario; combined with the ever constant
pressure of urban sprawl this habitat is in grave danger. Not only do
wetlands keep our waterways clean, they are also home to a group of
animals who depend on this habitat for survival. During carp spawning
months, they move into the shallows to build their nests, where upwards of
80,000 eggs can hatch by the end of August. While building their nests
they stir up the bottom causing the water to become cloudy and turbid.
This turbid water reduces the amount of light entering the water that is
needed for the survival of plants and other organisms within the
wetlands.
The Common Carp is also an omnivorous fish
with an aggressive appetite, its diet consisting of mainly of aquatic
insects, snails, algae and seeds from aquatic plants; this adaptive diet
has been devastating to wetland ecosystems. While it can consume a variety
of plant and animal tissue from mollusks to mulberries, being a bottom and
surface feeder means it can control all the food and starve other wetland
organisms. These are just a few reasons why it has adapted to so many
diverse waterways across
North America.
It is because of the devastating effects
carp have had on wetlands that several carp control techniques have been
be employed in wetlands across Ontario including fish ways, carp
partitions, water filled dams and fencing systems to name a few. Carp
partitioning is employing organic matter, such as Christmas trees, to
create a barrier restricting access to carp while allowing the
establishment of wetland vegetation. Today, the Frenchman’s
Bay Watershed Rehabilitation Project is working to restrict carp from
sections of Hydro Marsh, a provincially significant wetland. While this
marsh has changed over the years, it has remained a significant home to
many migratory birds, turtles, countless invertebrates and other
organisms.
Two organic barriers have been constructed
in Hydro Marsh, one at the north end of the Marsh; the other in the south
off the barrier beach. These barriers were created with cedar posts
connected by steel wiring and recycled Christmas trees, provided by the
City of Pickering. There has also been a passage for small fish spawning
incorporated in these structures. Species including pike, walleye and bass
that help control Common Carp populations via predation are among the many
fish that spawn in these newfound vegetative wetland areas. Therefore by
restoring the aquatic plants that filter out sediments, it cleanses the
water and also provides food for many species.
If you are seeking more information
regarding the restoration of the Frenchman’s Bay watershed, please call
the office at 905.420.4660 ext. 2212 or email us at stewardship@pickering.on.ca
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