Scientists have long known that so-called red tide phytoplankton is toxic to marine life, but new research from the University of Connecticut is suggesting that it's actually far deadlier than we feared. Professor Hans Dam from the Department of Marine Sciences has sounded the alarm on the red tide, saying that it could have grave consequences for entire marine food chains.
The revelation came after Dam's discovery that the plankton produces not one, but two deadly toxins. The red tide, more formally known as Alexandrium tamarense, produces a double-shot of chemicals — one that's deadly to large organisms, and one that's deadly to small predators. Because of its ability to kill both of these groups of animals, it has lead Dam to label it as the potential "killer of the ocean world."
Adding insult to injury is how these plankton can contaminate the human food supply. While the red tide poses no immediate threat to humans, its downstream effects could impact on lobsters, clams, and fish — which in some instances have caused human deaths.
Red tides are the result of large concentrations of aquatic microorganisms, in this case the A. tamarense plankton. It can exist in both fresh and salt water, and can often be found in coastal areas. And because the plankton contains photosynthetic pigments that vary in shades of green, brown, and red, the overall look of the algal bloom is a kind of crimson red, or greenish yellow. There are even some variants of the tide that have no color at all.
These tides have already made an impact in various parts of the world. A particularly nasty episode came off the coast of New England in 2005 — an outbreak that wreaked havoc to wildlife and the fisheries industry.
The study, which was recently published online in Aquatic Microbial Ecology, suggests that there's more of this to come — and that these blooms could impact on larger swaths of the ocean. What makes the red tide particularly pernicious is its ability to consume its own predators, leading the researchers to wonder how the tides could ever be controlled in the future.
The researchers are not completely sure what causes the widespread growth of red tides. They believe that pollution from rivers is party to blame, but that there are other environmental factors to consider as well.
The next phase of the study will be to see how the alga produce the predator killing reactive oxygen, and whether it also affects multicellular animals.
You can read the entire study.