C-HARM Model (California-Harmful Algal Risk Mapping)

C-HARM HAB Model (California-Harmful Algal Risk Mapping)

Experimental Data - Use Cautiously

 

Pseudo-nitzschia Nowcast

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.

Particulate Domoic Acid Nowcast

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.

Cellular Domoic Acid Nowcast

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.

Cellular Domoic Acid (cDA) is a measure of how toxic the cells are in terms of per cell toxicity. Particlulate Domoic Acid could be thought of as a standing level of DA across all cells at the surface. Cellular DA appears to be a better representation of where food web effects are likely occurring, although this is not always the case. Research is being done to better understand this linkage.

Predictions of harmful algal bloom (HAB) conditions are created through a combination of 1) sophisticated circulation models that predict the ocean physics, 2) satellite remote-sensing data of the ocean “color” and chlorophyll patterns, and 3) statistical models for predicting bloom and toxin likelihoods. These predictions are generated daily to provide a forecast of where you might encounter a Pseudo-nitzschia bloom and/or domoic acid event in the next one to three days.

 

We are soliciting the community to consult our product and provide feedback, particularly if HAB predictions have the potential to help in decision-making activities. The quick survey will help guide improvements and allow us to report to NASA what you, as important end-users, think about our product.

User Survey