What causes unsafe levels of PSP?
It’s normal for biotoxin-producing algae to be present in marine water. They are usually at very low concentrations and pose no problems. However, when the algae “blooms” the concentration increases dramatically. The increased algae simply becomes a greater food source for shellfish. The more algae the shellfish eat, the more biotoxin they accumulate. Biotoxins don’t harm shellfish, so the level in their tissue continues to climb until the bloom subsides. When the number of toxin-producing algal cells returns to normal low levels, the shellfish eventually flush the toxin from their systems. It can be several days to several months or longer before they’re safe to eat again. What causes PSP blooms? When water conditions are favorable, the algae “blooms” and reproduces. Continuing research has pointed to certain cause and effect situations, but the exact combination of conditions that cause the blooms is not yet known. The National Office for Harmful Algal Blooms has an excellent site th
