open access

https://hdl.handle.net/2115/82422

Photoacclimation by phytoplankton determines the distribution of global subsurface chlorophyll maxima in the ocean

英語

2021-06-18

Springer Nature

Communications Earth & Environment

2

128

Subsurface chlorophyll maxima are widely observed in the ocean, and they often occur at greater depths than maximum phytoplankton biomass. However, a consistent mechanistic explanation for their distribution in the global ocean remains lacking. One possible mechanism is photoacclimation, whereby phytoplankton adjust their cellular chlorophyll content in response to environmental conditions. Here, we incorporate optimality-based photoacclimation theory based on resource allocation trade-off between nutrient uptake and light harvesting capacity into a 3D biogeochemical ocean circulation model to determine the influence of resource allocation strategy on phytoplankton chlorophyll to carbon ratio distributions. We find that photoacclimation is a common driving mechanism that consistently explains observed global scale patterns in the depth and intensity of subsurface chlorophyll maxima across ocean regions. This mechanistic link between cellular-scale physiological responses and the global scale chlorophyll distribution can inform interpretation of ocean observations and projections of phytoplankton responses to climate change. Trade-offs in the cellular allocation of resources in response to environmental conditions consistently explain the depths of subsurface chlorophyll maxima across the global ocean, according to simulations with a biogeochemical ocean circulation model.

学術雑誌論文

Version of Record

2662-4435