Brooklin Lions Wilderness Trail > Trail Guide > Post 4

Revised June 6/01. The latest version of the guide is always available on

Post 4: Life in the Creek

As anyone who has gone fishing knows, there is life in a healthy creek. The fish the angler seeks is only a part of the living community of the stream. Feeding the fish are aquatic insects, crustaceans, and molluscs which in turn feed on other tiny animals or plants. Through photosynthesis, algae and other plants ultimately transfer the sun’s energy into food energy that supply the aquatic ecosystem.

This section of the East Lynde Creek is classified as a warm water fishery by the Central Lake Ontario Conservation Authority (CLOCA). Their 1983 study of the entire Lynde Creek watershed recorded 10 species of fish in the East Lynde including the Red-side Dace, a nationally vulnerable species listed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The Red-side Dace is a small minnow that prefers shaded, cool, flowing waters as found by Winchester Road and to the south. A survey of fish species in 2000 found 11 species, but not the Red-side Dace. Perhaps if more people grow trees and tall plants along the creek banks to provide shelter and shade, the vulnerable dace will flourish again in the East Lynde.

The creek also serves as a migration corridor for spawning fish. In 1983, CLOCA recorded Rainbow Trout north and south of the trail. In 1999 White Suckers were observed moving upstream to spawn. Under the rocks, logs, and grassy edges are numerous invertebrates. The presence, or lack thereof, of certain species serves as indicators of water quality. A survey of the invertebrates in three sections of the creek in Fall 2000 found ratings of good, good, and fairly poor.

Hey Kids!


Some fish travel upstream to spawn or lay their eggs. These eggs turn into small fry or baby fish which later travel downstream where they become adults. Can you think of any other animals that travel or migrate to have their young?


If you are with an adult, travel to a creek and pick up and turn over a rock. If you are lucky you may get to see the insect larvae and nymphs that live on the rock. What do you think these animals eat? What do you think eats them?


In the early autumn there are a lot of insects in, on, and near the water. Can you name the different kinds of insects found near streams and ponds.


Do you think anything is living under the ice? Of course, there is! Fish, insects, crustaceans, molluscs, and tiny microscopic plankton are all living in the creek in the winter, but because they’re cold-blooded they’re not moving around too much. Remember, stay away from the edge of the creek. Even if it appears frozen, it’s not safe.

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