Organisms adapt to predation risk by changing their behavior. A new study from the Centre for Ocean Life demonstrates how defensive behaviors of marine pelagic organisms, from phytoplankton to fish, may significantly change the intensity of the biological carbon pump and, hence the ability of the ocean to sequester carbon.
Marine prey in the water column have adopted a wide range of behaviors to defend themselves from predation. Some zooplankton and fish perform diel vertical migration and go at depth to hide from visual predators during daytime, fish can school to protect themselves from larger predators, tiny algae can create toxic compounds to become inedible…
All these anti-predation behaviors disrupt trophic interactions and, consequently, change how much carbon is eaten, respired, and excreted at different depths and places in the oceans. This may have important consequences for marine carbon export by the biological pump – the transport of photosynthetically fixed carbon from the surface of the oceans to the depths. For example, diel vertical migrations means that carbon will be respired directly at depths, where it is stored on longer time scales than if it were respired at the surface.
In this study from the Centre for Ocean Life, we have assessed how anti-predation behaviors from open water organisms may affect carbon export in the oceans, thanks to both direct and indirect cascading effects through the food-web. We review a wide range of anti-predation response, investigating qualitatively how each could disrupt and modify the biological carbon pump. Except for diel vertical and seasonal vertical migrations of zooplankton and fish, the quantitative effects of behavior on the biological carbon pump are unknown. By identifying the most important mechanism this study will encourage scientists to consider animal behavior in future biological carbon pump studies.
Read the paper here: http://doi.org/10.1002/lno.12073
Pinti J, Visser AW, Serra-Pompey C, Andersen KH, Ohman MD, Kiørboe T (2022) Fear and loathing in the pelagic: How the seascape of fear impacts the biological carbon pump. Limnology and Oceanography, https://doi.org/10.1002/lno.12073