11/07/2023
Do you keep fish in your coral tank? They could be doing more than just keeping algae and pests in check.
What is known is that all marine fish ingest calcium-rich seawater and produce magnesium-rich calcium carbonate precipitates in their intestines, excreting it at high rates to the environment alongside and within their f***s. “The production and excretion of these carbonates, which we call ichthyocarbonates, is a fundamental process, and it’s critical to their survival. Without it, fish would become dehydrated in seawater and die,” said Amanda Oehlert, an assistant professor in the Department of Marine Geosciences and the lead investigator of the three-year study.
As they sink, the ichthyocarbonates dissolve, making seawater more alkaline in ways that are not accounted for in current models.
About 15 years ago, Grosell and his colleagues estimated that fish produce 3 percent to 15 percent of the calcium carbonate in our oceans. “But technological advances have revealed that there are more fish in the sea than we initially appreciated in 2009,” Grosell explained. “So, we’ve revisited those calculations, estimating that the number is even greater. Fish may, in fact, be among the most prolific producers of carbonates in the ocean. So, we’re trying to lock that number down with more accuracy.”
Three researchers from the University of Miami are conducting experiments to better determine the important role fish play in the oceanic carbon cycle, studying everything from how much carbonate fish produce to the path of the minerals in the water column.