Abstract:
Upwelling, the process by which deep, nutrient-rich waters rise to the surface, plays a crucial role in driving marine ecosystem productivity. To gain a comprehensive understanding of how upwelling influences marine life across different trophic levels and habitats, we integrated two unique long-term datasets spanning over three decades. These datasets included surface oceanographic measurements and deep-sea lander observations from the Monterey Bay region, California, USA.
Our analysis revealed striking patterns in the responses of marine organisms to upwelling events. During periods of intense upwelling, primary production at the sea surface increased significantly, leading to higher abundances of phytoplankton and zooplankton. These changes propagated through the food web, resulting in increased biomass and diversity of higher trophic level organisms, such as fish and seabirds.
In the deep seafloor, upwelling had contrasting effects on different ecosystems. Enhanced food availability near the seafloor supported thriving communities of suspension feeders and other benthic organisms. However, the oxygen-depleted conditions associated with upwelling also caused mass mortality events among deep-sea invertebrates, particularly during strong upwelling events.
Overall, our long-term data integration underscores the intricate interplay between upwelling, primary production, and the dynamics of various marine communities. Our findings emphasize the significance of long-term observations in capturing the full complexity of marine ecosystem responses to environmental variability. This knowledge is essential for predicting and mitigating the impacts of changing ocean conditions on the health and functioning of marine ecosystems worldwide.
