Chlorophyll criteria based on zooplankton

Selecting parameters

The following parameter values can be specified that reflect risk management decisions that affect the criterion value.

  • Slope threshold - The targeted slope of the relationship between log-transformed zooplankton biomass and log-transformed phytoplankton biomass.

  • Certainty level - Because of model uncertainty, a range of criterion values are possible. The certainty level specifies the range (gray area) within which the criterion value is located with the specified probability. The level is quantified as the credible interval, a measure of model uncertainty that is similar to a confidence interval. For example, if a certainty level of 75% is selected, there is a 75% chance that the criterion is within the bounded region. To ensure that the estimated criterion is protective, the criterion magnitude is computed as the intersection of the lower bound of the gray area and the targeted threshold (shown as red line segments).

  • Latitude and Longitude - The geographic location of the lake of interest, used to compute the maximum seasonal temperature in the lake. The inset map shows the selected lake location as a filled yellow circle, and the four different lake temperature classes are shown with different colored dots.

Note: All sliders have been set to the middle of their range, but these initial settings should not be interpreted as recommended values.