University of Tasmania
Browse

File(s) stored somewhere else

Please note: Linked content is NOT stored on University of Tasmania and we can't guarantee its availability, quality, security or accept any liability.

Marine carbon cycling and sequestration is extremely sensitive to zooplankton grazing in biogeochemical models

preprint
posted on 2023-07-02, 22:52 authored by Tyler RohrTyler Rohr, Anthony Richardson, Andrew Lenton, Matthew Chamberlain, Elizabeth Shadwick
Abstract Zooplankton grazing regulates marine carbon cycling by constraining phytoplankton populations and the subsequent transfer of carbon to depth and higher trophic levels. Yet, without robust in-situ data to constrain them, the grazing formulation in state-of-the-art climate models varies largely. We present a new metric to compare how fast zooplankton are assumed to graze in 10 state-of-the-art (CMIP6) biogeochemical models and find they differ by nearly 2 orders of magnitude, implying an ocean populated exclusively with everything from slow-grazing krill to rapidly-grazing ciliates. We use a global, coupled ocean-biogeochemistry model to test the sensitivity of marine carbon cycling to this uncertainty and find the Net Primary Production (NPP) and export efficiency collapse across the range of plausible values. Even when tuned to identical NPP by increasing phytoplankton growth rates, export and secondary production remain extremely sensitive to grazing, likely biasing predictions of future climate states and food security.

History

Department/School

Oceans and Cryosphere

Publisher

Research Square

Publication status

  • Published online

Preprint server

Research Square

Rights statement

Copyright 2022 the authors. This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

UN Sustainable Development Goals

14 Life Below Water, 15 Life on Land

Usage metrics

    Institute for Marine and Antarctic Studies

    Licence

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC