Featured Image Credit: Oregon State University
By Kira Krall
Phytoplankton are microscopic plants found in the water column. They’re tiny organisms that cause a huge problem: shellfish poisoning. Under the right conditions, phytoplankton can bloom in massive quantities and produce large amounts of domoic acid. Ingestion of too much domoic acid can cause neurological issues such as lethargy, disorientation, and deadly seizures. It can affect everything that eats filter feeders like shellfish, from shorebirds to humans.
Morgaine McKibben and her team at the University of Oregon analyzed domoic acid data that’s been collected over 25 years and they noticed an interesting trend: there is a significant link between domoic acid-producing phytoplankton and warmer water temperatures. Cyclical weather patterns that warm the water also correlate with a huge spike in these dangerous algal blooms.
Pictured above is Pseudo-nitzschia, the genus of phytoplankton responsible for producing domoic acid. Other groups of phytoplankton can produce harmful blooms, like diatoms and dinoflagellates. Image Credit: Scottish Association for Marine Science
Ironically, shellfish poisoning doesn’t seem to affect shellfish. But it can cause illness in other animals that feed on the phytoplankton directly, especially filter-feeding whales. Unfortunately, shellfish poisoning is usually detected only after people and wildlife start getting sick. This is just as much a health hazard as it is a deficit to fisheries, since their product is now unmarketable until the harmful algal blooms clear. Dangerous phytoplankton causes an annual loss of $100 million dollars in the U.S. Dungeness crab fishery alone.
Morgaine McKibben has also conducted plankton research using a plankton net, shown above. Image Credit: COAS
What McKibben hopes to do is create an early warning system for fisheries. Analyzing global temperature increases and meteorological events can predict temperature spikes and the resulting harmful algal bloom of heat-loving phytoplankton. Holding off harvesting until after the blooms clear allows domoic acid to filter out of the shellfish naturally.
This type of research supports the fact that public health and ecosystem health go hand in hand. Future studies will hopefully tell us more about the microscopic rulers of the ocean and what we can do to protect ourselves from their tiny wrath.