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Landry MR, Hood RR, Davies CH
Mesozooplankton biomass and temperature-enhanced grazing along a 110°E transect in the eastern Indian Ocean
Climate warming of low-latitude oceans is predicted to decrease productivity, increase metabolism and cause phytoplankton size shifts that may reduce trophic transfer to zooplankton. In May and June 2019, Landry and colleagues investigated trends in zooplankton biomass and grazing along the historic Indian Ocean 110°E transect line spanning a pronounced 14°C temperature gradient. Both biomass and grazing increased significantly from higher to lower latitude. Carbon-specific grazing was strongly related to temperature and contributed more to satisfying zooplankton energetic requirements in low-chl a tropical waters than chl a-rich temperate waters. This unexpected result suggests that mixotrophy might enhance trophic coupling in tropical waters and highlights the need to validate assumptions about the climate sensitivities of low-latitude ecosystems.