| Thirty
species of fish are now known to exist in the marsh.
Eight species are believed to be recent introductions
through human activities. Carp were introduced to
the marsh in the late 1940s and are thought to be
responsible for many of the changes that have been
seen in the marsh. Through their feeding and spawning
activities they uproot aquatic vegetation, stir
up the bottom sediments, and contribute to the cloudiness
of the water. As early as the 1960s, carp were being
blamed for many of the changes observed in the marsh.
However, we know very little about how carp use
the marsh and the habitats that they prefer.
Table 1- Fish species of Delta Marsh
The central mudminnow, bigmouth
buffalo, channel catfish, tadpole madtom, brown
and black bullhead, and rock bass are believed
to have been introduced following operation
of the Assiniboine River Diversion in 1970.
These species were present in the Red and Assiniboine
River systems, but had not been reported in
Delta Marsh prior to the construction of the
diversion.
To gain a better understanding
of the larger fish species present in the marsh,
Ducks Unlimited embarked on a two year field
sampling program in 1998. Walleye Tracker is
one component of this study.
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Walleye
Stizostedion vitreum |
