Oxygen content in the water is critical to fish in the same way oxygen in the air is critical for us. The way we measure oxygen content for fish is milligrams per liter (mg/L) of dissolved oxygen, or DO. Habitat requirements, such as average DO requirements, are useful in our research and monitoring programs for interpreting our data and designing management actions.
What is meant by average dissolved oxygen requirements?
I recently created two figures to accompany the quick reference poster of water quality on the Henry’s Fork that was featured in our blog post on October 30th. These figures illustrate the optimal, sub-optimal, stressful, and lethal temperature ranges for Brown Trout (Salmo trutta) and Rainbow Trout (Oncorhynchus mykiss).
To support our water quality monitoring efforts, we have a new quick reference poster in the office! For now, the poster displays the recent, daily range of dissolved oxygen (averaged over the previous 4 days) and the weekly average temperature from our sampling/sonde sites. We have seven sites that we capture data from; I download data from 3 of the sondes one week, then retrieve data from the remaining 4 sondes the following week. Therefore half of the displayed data are from the previous week, and the other half of the site data are two weeks old.