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Warmer ocean waters have been linked to increased toxic shellfish.
One of the many effects of climate change is that the water of oceans is gradually getting warmer. A new study has discovered that the toxic shellfish caused by increased levels of domoic acid in the bodies are more prevalent in warmer waters.
For their study, the researchers analyzed data from two decades of monitoring and analysis, between 1991 and 2015. They compared the conditions of the ocean water found off the coast of Oregon with the domoic acid levels in razor clams found in Oregon’s coastal waters. The researchers performed their comparison using the Pacific Decadal Oscillation (PDO), a measure of climate variability which takes into consideration both the ocean temperature as well as the currents.
After an extensive analysis, they discovered that the years with an overall warmer climate which also lead to higher ocean temperatures and currents had an increased amount of toxic shellfish due to increased levels of domoic acid in the bodies. More specifically, the researchers determined that the five years with the highest recorded domoic acid and toxic shellfish coincided with the years were the ocean’s waters and current were the warmest.
Domoic acid can usually be found in marine algae and it’s a dangerous neurotoxin in larger quantities as it accumulates in the bodies of shellfish and other marine life which consume the algae. As such, it can easily become ingested by people if they consume shellfish with high amounts of domoic acid. Those who do so will develop domoic acid poisoning, a neurological disorder also known as amnesic shellfish poisoning. It mostly involves symptoms such as diarrhea, stomach pains, seizures, memory loss, or even death in rare cases.
According to Morgaine McKibben, the study’s lead author as well as a doctoral student at the Oregon State University, more than 70 percent of the 1,500 razor clams examined by 2016 since the start of the study, had levels of domoic acid lower than 20 parts per million. Fortunately, scientists routinely test for toxic shellfish and prevent their harvest. This what prevent what could have been a high number of deaths and illnesses.
The researchers also developed a model which tracks the change in climate conditions related to domoic acid. As such, they can reliably determine when toxic shellfish will become more prevalent and issue appropriate warnings.
Image source: Wikimedia
