Trophic flows to mesozooplankton support the conventional paradigm of pelagic food web structure in ocean ecosystems
Year: 2024
Type: article
Abstract: The current conventional paradigm of ocean food web structure inserts one full level or more of microzooplankton heterotrophic consumption, a substantial energy drop, between phytoplankton and mesozooplankton. Using a dataset with contemporaneous measurements of primary production (PP), size-fractioned mesozooplankton biomass, and micro- and mesozooplankton grazing rates from 10 tropical to temperate ocean ecosystems, we examined whether the structural inefficiencies in this paradigm allow sufficient energy transfer to support active metabolism and growth of observed zooplankton standing stocks. Zooplankton carbon requirements (ZCR) were determined from allometric equations that account for ecosystem differences in temperature and size structure. ZCRs were relatively low (∼30% of PP or less) for both oligotrophic systems and bloom biomass accumulation in eutrophic coastal waters. Higher relative ZCRs (>30% PP) were associated with elevated mesozooplankton grazing scenarios (bloom declines, abundant salps), advective subsidies, and open-ocean upwelling systems. Microzooplankton generally dominated as grazers of PP but were equal or secondary to direct herbivory as nutritional support for mesozooplankton in five of eight regional studies. All systems were able to satisfy ZCR within the conventional food-web interpretation, but balanced open-ocean upwelling systems required the most efficient alignments of contributions from microzooplankton grazing, direct herbivory, and carnivory to do so.
Source: ICES Journal of Marine Science
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Life below water
Open Access status: gold
Estimated APC paid: $3,751
Awards: Collaborative Research: Hawaii Ocean Time-series: Biogeochemistry and Ecology Component, Collaborative Research: Quantifying trophic roles and food web ecology of salp blooms of the Chatham Rise, Response Of Microbial Community Structure And Protistan Grazing Pathways To Environmental Forcing In The Arabian Sea, Collaborative Research: Mesoscale variability in nitrogen sources and food-web dynamics supporting larval southern bluefin tuna in the eastern Indian Ocean, G387054980, Collaborative Research: Influences of Cyclonic Eddy Activity on Planktonic Food Web Dynamics and Carbon Export in the Lee of Hawaii, Hawaii Ocean Time-series (HOT): 2023-2028, LTER: Nonlinear transitions in the California Current Coastal Pelagic Ecosystem, Collaborative Research: Grazing and Iron Controls of Diatom Blooms in the Arabian Sea
OpenAlex ID: W4402543876