DOMOIC ACID: Domoic acid is an amino acid that is associated with algal blooms. It can cause neurological damage to marine animals such as shellfish, sardines, and anchovies that feed on the tiny phytoplankton that produce the dangerous chemical. If they eat infected animals, people can ingest it. In people, domoic acid can cause memory loss, brain damage, and even death. The acid may even have caused an invasion of thousands of seabirds into coastal California towns in 1961.
BIOACCUMULATION AND CLAMS: Clams are filter-feeders, meaning they draw water into their shells, remove the food they find, and then draw in more food-rich water to continue feeding. This means that large volumes of water work their way through clam shells. The muscle of the clam gathers not only food, but other material suspended in water during this process, which can lead to the accumulation of toxins and pollutants. Bioaccumulation is the term for toxins and pollutants that collect in the tissue of an organism. Biomagnification is a related term, referring to the transfer of such substances from prey to predator. If a prey animal bioaccumulates toxins in its body, then its predator, after consuming many of the smaller animals will accumulate many, many times the amount of the toxin in any one of their prey.
The American Geophysical Union contributed to the information contained in the TV portion of this report.