The dissolved oxygen concentration in water can directly affect reproduction, incubation, changes in species, and death of adult and juvenile fish and other organisms. In general, DO values for the four sites were acceptable for both salmonid juvenile growth and reproductive-larval phases, although slightly lower DO rates during the early winter may be necessary for reproductive and larval stages. Turbidity Turbidity is a measure of the amount of suspended particles in the water. Watersheds in general have a natural turbidity level with inputs from natural erosion, organic decay and algae. There has been no determination of the natural turbidity level in most of the local watersheds in Santa Cruz County.
Turbidity can be an indicator of erosion, excessive nutrient loading and algal growth.
Turbidity levels recorded within the watershed were relatively low during the July-December period. Sites 1 and 2 maintained the lowest turbidity measurements averaging 5 JTU overall. Elevated turbidity readings were measured on 7 November at all four sites indicating recent rain activity. The 21 August reading at site 3 was the only sample that exceeded the standards set. As the pH increases, water becomes more acidic and as water become more basic, the pH increases.