Research by the Biodiversity Research Center and Institute of Oceanography, National Taiwan University in Taiwan, has linked intermediate-depth fish populations and diversity to ocean temperatures through fossilized inner ear bones of fish.
In the paper, “Ocean temperature drove changes in the mesopelagic fish community at the edge of the Pacific Warm Pool over the past 460,000 years,” published in Science Advances, the team reconstructs the history of mesopelagic ocean ecosystems to reveal that anthropogenic ocean warming will lead to marine ecosystem degradation.
Mesopelagic fish are any fish that reside at ocean depths between 650 and 3,300 feet (200–1,000 m). These fish populations are constantly in diurnal vertical migration, moving up and down within the water column following food or avoiding predators. Their role in linking the surface and deep-ocean ecosystems is essential for the biological carbon pump.
Using extraordinarily well-preserved fish otoliths (inner ear bones) found in sediment cores collected from the ocean floor between Papua New Guinea and the Solomon Islands, 1,130 otoliths from 343 sediment samples were analyzed, representing 28 taxa from 12 families.
The study finds that over the past 460,000 years, fish production and diversity followed hump-shaped temperature gradients. The record shows it takes less temperature change to negatively affect diversity than overall production by ~1.5° to 2.0°C. During the warmest interglacial periods, both production and diversity declined drastically.
2023-07-13 16:48:02
Link from phys.org