Global change drives modern plankton communities away from the pre-industrial state

Abstract

The ocean-the Earth's largest ecosystem-is increasingly affected by anthropogenic climate change 1,2 . Large and globally consistent shifts have been detected in species phenology, range extension and community composition in marine ecosystems [3][4][5] . However, despite evidence for ongoing change, it remains unknown whether marine ecosystems have entered an Anthropocene 6 state beyond the natural decadal to centennial variability. This is because most observational time series lack a long-term baseline, and the few time series that extend back into the pre-industrial era have limited spatial coverage 7,8 . Here we use the unique potential of the sedimentary record of planktonic foraminifera-ubiquitous marine zooplankton-to provide a global pre-industrial baseline for the composition of modern species communities. We use a global compilation of 3,774 seafloor-derived planktonic foraminifera communities of pre-industrial age 9 and compare these with communities from sediment-trap time series that have sampled plankton flux since ad 1978 (33 sites, 87 observation years). We find that the Anthropocene assemblages differ from their pre-industrial counterparts in proportion to the historical change in temperature. We observe community changes towards warmer or cooler compositions that are consistent with historical changes in temperature in 85% of the cases. These observations not only confirm the existing evidence for changes in marine zooplankton communities in historical times, but also demonstrate that Anthropocene communities of a globally distributed zooplankton group systematically differ from their unperturbed pre-industrial state.To determine whether anthropogenic climate change has affected the marine environment beyond its natural state, it is essential to compare modern observations to a pre-industrial baseline. Because such a baseline is available for the physical state of the ocean, it has been established that, in response to global warming, the sea-surface temperature field has changed significantly since the onset of industrialization approximately 170 years ago 1,2 (Fig. 1). Marine ecosystem research, on the other hand, is almost exclusively based on observations since the mid-twentieth century and the pre-industrial baseline is therefore mostly unknown. Although existing observations provide strong evidence for changes in marine ecosystems in a direction that is consistent with late-twentieth century climate change 3,4,10,11 , this lack of a pre-industrial reference prevents assessing the degree to which Anthropocene marine ecosystems differ from their natural, preindustrial state 12 . This affects our ability to predict the effects of global change on marine ecosystem functioning and the resulting impacts on the resources that they provide to society.Planktonic foraminifera are a globally ubiquitous group of marine zooplankton. Their distribution is primarily controlled by temperature 13,14 . About 40 morphospecies are known 15 ; they occur most abundantly in the surface mixed layer, but some s...

Development, Productivity, and Seasonality of Living Planktonic Foraminiferal Faunas and Limacina helicina in an Area of Intense Methane Seepage in the Barents Sea

“…For example, the species diversity has increased over the past few decades. There is a higher concentration of the subarctic species Orcadia riedeli , Globigerinita uvula , and Neogloboquadrina incompta (Meilland, ; Meilland et al, ) in polar regions compared to preindustrial times (Jonkers et al, ) (Figures and ). The observed recent increase in LPF diversity highlights that the Arctic and polar LPF community is changing.…”

“…The reproduction rates of living planktonic foraminifera (LPF) change in response to changes in the environment with higher rates under favorable conditions and vice versa (Kucera, ). The global LPF community has changed since preindustrial times in terms of the spatial distribution of assemblages (Jonkers et al, ). The shift in the global LPF community is consistent with recent changes in temperature, demonstrating the sensitivity of the LPF to environmental conditions (Jonkers et al, ).…”

“…The global LPF community has changed since preindustrial times in terms of the spatial distribution of assemblages (Jonkers et al, ). The shift in the global LPF community is consistent with recent changes in temperature, demonstrating the sensitivity of the LPF to environmental conditions (Jonkers et al, ). Yet our understanding of LPF ecology is fragmented, especially in the northern polar regions.…”

On the mismatch in the strength of competition among fossil and modern species of planktonic Foraminifera

“…Because there is no precise estimate of local sedimentation rate in most sampled sites, core samples hold information on species relative abundances (relative to the sampled assemblage, as all individuals are identified) rather than absolute abundances. Coretop samples represent time‐averaged assemblages on the order of hundreds to thousands of years depending on local sedimentation and bioturbation rates (Jonkers, Hillebrand, & Kucera, ). Such time‐averaged assemblages have the advantage of averaging out seasonal and inter‐annual fluctuations in abundance that might blur macroecological patterns (Fenton, Pearson, Jones, & Purvis, ).…”

“…All analyses were conducted using R (version 3.3.3, R Core Team, 2017). (Jonkers, Hillebrand, & Kucera, 2019). Such timeaveraged assemblages have the advantage of averaging out seasonal and inter-annual fluctuations in abundance that might blur macroecological patterns (Fenton, Pearson, Jones, & Purvis, 2016).…”