Research shows global warming making oceans more toxic
A team of scientists led by Dr. Christopher Gobler, marine science professor in the School of Marine and Atmospheric Sciences at Stony Brook University, used high resolution ocean temperature data along with the growth response of two of the most toxic algae in the North Atlantic and North Pacific Oceans called Alexandrium and Dinophysis. Their study demonstrates that since 1982, broad stretches of these ocean basins have warmed and become significantly more hospitable to these algae and that new 'blooms' of these algae have become common in these same regions. Alexandrium and Dinophysis are serious health concerns as they make neurotoxins and gastrointestinal toxins that can cause paralytic and diarrhetic shellfish poisoning in humans.
Marine algae are so tiny—50 of them side by side span only the width of a single hair—that they may seem harmless. But when billions of toxic cells come together, they can poison humans, kill marine life, and economically harm coastal communities. Economic losses attributed to this phenomenon over the course of the last decade have been estimated at more than one billion dollars.
While several studies have predicted that toxic algae blooms may become more common in the future, this is one of the first studies to link the recent intensification of these events to ocean warming. Confidence in the findings of the study came from the match of the findings to one of the central principles of global warming biology: Organisms (including toxic algae) will migrate towards the Earth's poles as warming progresses. And the identification of newly hospitable regions of the ocean for these algae in the study matches newly documented toxic algae blooms.
The study brought together biologists with climate scientists who made use of ecosystem observations, laboratory experiments, and thirty-five years of satellite-based temperature estimates that are made daily and with a very high degree of spatial resolution.
One of the trends in the study that is consistent with climate change science, in general, was the poleward migrations of these toxic algae, particularly in the North Atlantic. While the growth and duration of toxic blooms expanded between 40 and 60 degrees North latitude, the bloom season actually shortened at lower latitudes.
The study also has important consequences for policy and the future of the oceans.