The map image displays the probability that the abundance of toxin-producing species of the diatom Pseudo-nitzschia in coastal waters is at or above the “bloom” threshold of 10,000 cells per liter. A value of 0.7, for example, means there’s a 70% predicted probability of Pseudo-nitzschia blooms in that pixel.

The map image displays the probability that the domoic acid concentration in the bulk phytoplankton pool is at or above 500 nanograms per liter (= 0.5 µ/L). A value of 0.7, for example, means there’s a 70% predicted probability of a toxic event, although there is always the possibility that concentrations lower than 500 ng/L will lead to toxins in shellfish or strandings of marine mammals and birds.

The map image displays the probability that the domoic acid concentration per *Pseudo-nitzschia* (i.e. how toxic are the algal cells themselves) is at or above 10 picograms per cell (pg/cell).

To give a sense of the range, the highest cellular concentrations seen in the environment have not yet exceeded 200 pg/cell in the most toxic cells. A predicted probability value of 0.7, for example, means there’s a 70% probability that a 10 pg/cell level of toxicity is present in the phytoplankton, although there is always the possibility that concentrations lower than 10 will lead to toxins in shellfish or strandings of marine mammals and birds.