[an error occurred while processing this directive] My Water Quality: Aquatic Ecosystem Health - Streams, Rivers & Lakes

California Streams, Rivers and Lakes

Toxicity Categories

What do the toxicity categories mean?

The process used to characterize the magnitude of toxicity at each site was designed to take into consideration the widely varying number of samples and test endpoints (such as fish or crustacean survival) among sites. If any toxic samples were measured for a site, the site was categorized based on the most sensitive endpoint. This process considers both individual sample results and the mean results for sites with multiple samples.

  • Toxic indicates survival or algal growth in a sample is significantly lower than the control.
  • High toxicity thresholds specific to each test endpoint were calculated using a method developed for sediment quality evaluation (Bay et al., 2007).


[an error occurred while processing this directive]