A type of single-celled organism known as foraminifera (or forams) is thriving in the warm, alkaline waters of the eastern Mediterranean, contributing to beach formation with their calcium carbonate structures, according to new research.
Pamela Hallock, a biogeological oceanographer and a renowned professor at the University of South Florida’s College of Marine Science, generally finds little to celebrate about climate change.
Throughout her career, Hallock has focused on ocean studies. She heads USF’s Reef Indicators Lab and is well aware of how human activities have affected marine ecosystems.
Nevertheless, she observed a positive aspect in the findings of her recent research paper about foraminifera, published in the Journal of Foraminiferal Research.
“These forams are increasing rapidly in suitable habitats,” Hallock explained. “They are now so abundant that they are transforming into an economic resource in areas with warm temperatures and high alkalinity due to their role in beach formation.”
The specific foram species, Amphistegina lobifera, found thriving conditions in the warm, nutrient-scarce waters of the Mediterranean Sea after migrating north through the Suez Canal 60 to 80 years ago. Since then, A. lobifera populations have flourished in the eastern Mediterranean and have spread westward, raising concerns about their potential invasiveness in the area.
Despite these worries, A. lobifera could be advantageous for tourism in nations like Turkey, Hallock noted. Their calcium carbonate shells make for excellent beach sand. Shorelines that were once lined with rough volcanic and limestone rocks have now accumulated over half a meter of sand made up of the remains of forams and other shells.
“The speed at which these forams are constructing beaches in the region is comparable to the rates of rising sea levels,” Hallock remarked.
There is a possibility that A. lobifera may continue to thrive in a world that’s getting warmer and has increased levels of atmospheric CO2. Hallock pointed out in her paper that the genus Amphistegina first appeared on Earth during a time of elevated atmospheric CO2 levels, and warm, alkaline waters enhance their metabolic rates and shell development.
While A. lobifera is currently seen as invasive in the Mediterranean Sea, its existence in the area represents a return to habitats where it once thrived.
“These organisms previously lived in this region,” she stated. “Now, due to our environmental impact, we’ve made the environment suitable for them again.”
This recent study presents a distinctive viewpoint on how human actions influence marine ecosystems, and vice versa.
As Hallock and her co-authors mention in their research, “Could this resurgence of abundant shallow-water carbonate production ultimately bring local benefits as climate change continues?”
