The global ocean size-spectrum from bacteria to whales

The global distribution and climate resilience of marine heterotrophic prokaryotes

“…4). In contrast, all other environmental conditions being equal, zooplankton and fish community biomass is projected to decrease with warming 3,39 .…”

“…Marine heterotrophic prokaryotes (heterotrophic Bacteria and Archaea; hereafter prokaryotes) serve a key role in structuring marine food webs and biogeochemical cycles 1,2 . Across the global ocean, prokaryotes have been estimated to comprise ~30% of biomass in the water column 3 and respire over 50% of net primary production in surface waters 4,5 . As a result, they represent an important pathway by which dissolved organic matter is passed to higher trophic levels or sequestered to the deep ocean 6 .…”

“…From decades of observational studies, it is known that prokaryotes are abundant across the world's oceans, from the tropics to the poles and from surface waters to under the seabed 9,10 . These observations have been used to estimate total global marine prokaryotic abundance and biomass 3,9,[11][12][13] and for assessments of prokaryotic community structure over smaller scales 12,[14][15][16] . However, unlike for other groups such as phytoplankton [17][18][19][20] and zooplankton [21][22][23] , there exists no synthesis of prokaryote observations to determine how they change across global environmental gradients.…”