A Few Newcomers in the Rideau River

Common carp, Cyprinus carpio.

This fish has been blamed for destroying the spawning areas of many aquatic insects, amphibians and fish. Common carp roots in the mud along shorelines, and in doing so it uproots aquatic plants. This activity also increases the turbidity. Other fish will avoid these areas as the suspended particles block their grills. If eggs have already been laid in these areas, the particles will cover them and interfere in their development. [3, 4, 5, 6]

Red-eared slider, Trachemys scripta elegans.

Red-eared sliders have expanded their distribution into the Rideau River because they have been dumped there by pet owners. This species successfully over-winters in the River, but is not likely to reproduce at this latitude since its natural range is in warmer waters further south.

The red-eared slider competes with native turtles for food and basking sites. It can also occupy areas that are favourable nesting sites for native turtles. [3, 4, 5, 6]

Rusty crayfish were first captured in 1986 in the Jock River, which is a tributary to the Rideau River. Two years later, this species of crayfish was found in the Rideau River itself.

The rusty crayfish is an aggressive predator that dramatically reduces diversity of both aquatic plants and invertebrate populations, and defeats native crayfish species in competition for food and cover. Rusty crayfish have drastically reduced native crayfish populations in many areas of Ontario. [3, 4, 5, 6]

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