Stream Life

A creek is a body of water in motion. It is a lotic system, a fast running aquatic habitat like a river, rather than a lentic system, a calm or slow moving aquatic habitat like a lake or pond. A creek is a body of water in motion. It is a lotic system, a fast running aquatic habitat like a river, rather than a lentic system, a calm or slow moving aquatic habitat like a lake or pond.          

There are many microhabitats within the stream itself. Cushions of moss provide shelter and food and harbor many microscopic organisms and larger animals. Patches of leaves caught between rocks or a rotten stick in the stream also provide important debris habitats inhabited by many small animals. Rocks, still pools at the water’s edge, or the stream surface are examples of microhabitats within a stream ecosystem.

 It is common to find fish, minnows, crayfish, salamanders, turtles, and snakes, as well as macroinvertebrates (aquatic insects) in streams. Because the water is constantly moving, survival can be challenging. Each organism has adaptations to meet its needs for survival. Body shape, claws, gills, coloration, fins, etc. are just a few examples of adaptations that help them survive. Their main food-getting techniques are grazing, filter-feeding, and predation. Many aquatic organisms are filter feeders because the current carries food along, essentially delivering food right to them.

Mayfly nymphs, caddisfly larva, dragonfly nymphs, and damselfly nymphs are just a few examples of macroinvertebrates living on the stream bottom.  Many spend the majority of their life as larva or nymphs in the stream before metamorphosing into adults.  In the larval or nymph stage, they are found clinging onto and under rocks, hiding in the mud and dead leaves, or living among the plants on the stream edge.  These macroinvertebrates, both in the larval and adult stage, are important parts of the food chain.

Small fish and minnows can be seen swimming in the deeper parts of the water, and crayfish may be seen lurking in the deep pools or under tree roots. Salamanders can also be found around the edge of creek.

Many birds and mammals also frequent the stream. Raccoons and opossums come to feed and drink. Look for their tracks along the stream edge. You will hear many birds in the shrubs and trees bending over the stream. Be on the lookout for Mallard Ducks paddling around the stream or listen for the rattling call of a Belted Kingfisher as it flies just over the surface following the stream’s meandering path.           

Plants growing around the creek edge provide shade, food, and shelter to aquatic life. They also stabilize the stream banks, preventing erosion. Plants are also natural filterers and help decrease the amount of pollution entering waterways.

Many different things can affect the water quality of streams. Runoff, erosion, fertilizers, pesticides, tree removal, and invasive species are some factors having a negative impact on streams. Lancaster County is located within the Chesapeake Watershed. The biggest pollutant in this watershed is sediment from agriculture and development. It is important to make wise land use decisions to help keep our waterways clean. Remember, we all live downstream!

This is one of 11 (eleven) informational signs at Landis Woods Park.