For the past two years, Foster Creek CD has volunteered for Cascadia CD and U.S. Fish & Wildlife's Education Services to bring Kids in the Creek to North Central Washington's (NCW) high schools.
Contact us if your school is in Douglas County and you would like to participate.
This event is moving to a fall series. It will be offered next in September 2018.
After the samples are collected, students separate the various types of macro invertebrates into observation containers. Some samples are prepped to be viewed under a microscope.
A dichotomous key (a tool to identify an organism in which each stage presents descriptions of two distinguishing characteristics, with a direction to another stage in the key, until the species is identified) is referenced to determine the macro invertebrates discovered in the stream.
A caddisfly (Trichoptera) is a type of aquatic macro-invertebrate that is intolerant of water pollution, and therefore, an indicator of good water quality. Caddisfly larvae play a vital role in aquatic ecosystems, especially in the Northwest, as they are a significant food source for many fish and water bird species.
Caddisflies undergo metamorphosis through four life stages: egg, larval, pupal, and adult.
The picture above displays two types of larvae cases found in NCW. The first is made from lightweight stick debris and the other is a heavier case made from rocks, gravel, and sand. Typically, the latter is used to weigh down the caddisfly in faster stream currents.
These cases provide camouflage, shell protection from predators, and act as a barrier from the stream's abrasive substrate. The silk created by the larvae used to weave these cases is produced by a gland in the lower lips, called a "labium".
The shape of caddisfly cases, along with the types of materials used to create them, vary between different caddisfly species. There are approximately 1,340 species in North America. Examples of materials used to create these cases are sand, gravel, and sticks.