Insect Survey of Permanent and Seasonal Streams
By:
Blaine Robbins
bmrobbins@csuchico.edu
Connor Lydon
Cjlydon@csuchico.edu
Blaine Robbins using a dip net in Mud Creek
You may think that bugs are disgusting or creepy, but they are hugely important little critters for many reasons. They are crucial to the environment and can tell us a lot about the health of an ecosystem and water quality. Pollution, contamination, and excessive siphoning are major contributors to poor water quality and its effect on aquatic ecosystems. A good and clear indicator of water quality is the presence ,or lack thereof, of aquatic insects. Many aquatic insects are sensitive to pollution and contamination and may indicate the health of a stream or river especially in an agricultural area. This can directly tell us the quality of water that is being used for agriculture and crops in the immediate area, which could possibly be a health concern. The variety of insects found is the important aspect, as some insects may be more sensitive than others. It’s also important to note that this study took place following the wet season, in a stream that flows all year round compared to a stream that would dry up during the dry season. This could potentially tell us how a dry year could drastically affect aquatic ecosystems and the water quality in the general area. In addition, we can infer that species found in the seasonal stream are better colonizers due to the significant shift in habitat from dry creek bed to wet creek.
Stony Creek, 2 miles south of Hamilton City, Ca
The diversity of insects in the streams is a direct result of how we treat our water, in the upper streams of the Sierra Nevada Mountains where humans have little to no impact the stream health is immaculate. With near perfect biodiversity, no pollution, and no water being siphoned off to feed cities the diversity of insects is immaculate and near untouched. At the base of the foothills in the California Central Valley, we surveyed two streams. Stony Creek is a permanent stream fed by the Black Butte Dam on the west side of the valley, and the other is Mud Creek which dries up in the summer due to lack of water supply and over use. We got in the water and surveyed the insects and other life we could find on the bottom of the creeks in Late March of 2025. In our nets we caught 400 organisms which we brought back to our lab to identify and categorize them. From this we were able to use these insects to help us better understand the differences or lack of differences between the permanent and seasonal streams. In our samples we noticed a significant amount of one specific Order of insects, the Ephemeroptera or commonly known as Mayflies. This order of insects we broke down into 4 families to compare the two streams and we found that there was a significant difference in the presence of the families in the streams. We were unable to determine why there would be a difference in the two streams that would lead to such a significant difference in Mayfly proportions.
Mud Creek, 5 miles east of Hamilton City, Ca
Aquatic insects, mainly the mayfly, are an important food source for many animals including birds, frogs, and fish. In California’s efforts in bringing back and restoring the salmon population, mayflies are a huge part of their diet. Many young salmonids feed off mayflies, which were a common find in our study. The presence of mayflies is important not only for the health of an aquatic ecosystem but also to provide a key food source to a species that California is putting in a lot of effort to restore. Unfortunately, we were not able to come to a conclusion as to why we found the results we did, however, future research into bringing Salmon and other fish back to the streams of the Sierra Nevada foothills would benefit from more research on these insect populations.
B. Robbins and C. Lydon in Stony Creek collecting insects