Recent research has highlighted the significant contribution of deep-sea fish to the ocean's carbon cycle. These fish, particularly mesopelagic species, excrete carbonate minerals at rates comparable to their shallow-water counterparts, validating previous models that suggest marine fish are major contributors to biogenic carbonate production in the ocean.
Scientists at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science studied the blackbelly rosefish, a deep-sea species living at depths of 350–430 meters. They found that these fish excrete approximately 5 milligrams of ichthyocarbonate per kilogram per hour, aligning with predictions from thermal and metabolic scaling models. This discovery confirms that depth and pressure do not inhibit ichthyocarbonate formation, strengthening global estimates of fish-derived carbonate production.
These findings underscore the importance of ichthyocarbonate in the ocean carbon cycle, especially given the vast, underexplored biomass of the mesopelagic zone. The research opens new avenues for studying deep-sea carbon dynamics and may improve Earth system models, which incorporate interactions between physical, chemical, and biological processes, such as biological carbon production and export.
Understanding the role of deep-sea fish in the carbon cycle is crucial for developing effective strategies to mitigate climate change and protect marine ecosystems.