Pesticides

Spectrum Framework

The Segarra Lab is collaborating with the Lydy Lab at SIU to measure the effects of insecticides on Chinook Salmon. Louise Cominassi, a postdoc, is observing the physiological and behavioral effects of two commonly used insecticides. This data will provide a framework of reference for law makers to know how the pesticides we use today might be affecting aquatic life. Below on the left Chinook Salmon are exposed to Bifenthrin, the most commonly used insecticide. On the right, Louise measures swimming performance.

Chinook Salmon behavior is also recorded and analyzed. Here you can see our Ethovision system at work tracking the movements of each individual fish.

Spectrum Framework 2.0

To provide a better understanding of how Chinook Salmon accumulate pesticides in the wild, Post-Doc Louise Cominassi has deployed cages of juvenile Chinook Salmon in areas of interest around the Delta. After a few weeks of living inside the cages, the fish are collected and analyzed for pesticide body burden (amount of pesticide accumulated within the body). While other studies have measured environmental concentrations of pesticides, this study is unique because it focuses on the amount of pesticide the fish are accumulating within the body.

(Top and Right) Louise Cominassi and the Fangue Lab boat crew deploy cages.

When it Rains, it Pours – Stormwater Contaminants

During the wet season in California, rain washes agricultural runoff and other contaminates into aquatic ecosystems. This is especially apparent in urbanized areas, such as the California Bay-Delta system. In addition, rainy season coincides with the spawning of fish species of concern.

In the stormwater project Delta Smelt, a small fish endemic to the SF Bay-Delta system, are exposed to stream water before, during and after a rainstorm.

To study behavior on small fish, such as Delta Smelt larvae, we use a system called DanioVision to record the fish on a temperature controlled well plate. The recording is then analyzed by tracking software.

The video above is at 4x speed but it demonstrates how the Ethovision software tracks individual fish movements. See if you can spot any erratic behaviour!

Contaminants in the Sacramento Deep-Water Shipping Channel

Stay tuned for more fall fieldwork on this project!