Dmitri Mauquoy

Monitored seabird populations have declined by up to 70% worldwide since the 1950s. Yet, data on long-term seabird population dynamics prior to the anthropogenic era are largely unknown. This limits our ability to understand future population trajectories, particularly in the Southern Ocean, where seabirds are facing multiple environmental threats. Here, we use mercury (Hg) derived from seabird guano in peatland catchments as a tracer of colony population sizes on sub-Antarctic Bird Island (South Georgia). Peat Hg flux and isotope signature results show that the first sustained seabird colonies after deglaciation were established on the island between 6800 and 6100 years ago, predating evidence for colonization on other sub-Antarctic islands by more than 1,000 y. The four subsequent periods with large local seabird populations occurred during phases of less intense Southern Hemisphere westerly winds. Our study unveils significant and repeated millennial-scale shifts in seabird abundance in response to natural climate changes, implying that the present-day increase in westerly wind intensity may lead to further declines in seabird populations in the Southern Ocean.

This study investigates the vegetation and hydrological dynamics of Linje peatland in northern Poland during the past ∼11 500 years by integrating testate amoebae and plant macrofossil analyses. The Linje profile is currently the only complete Holocene peat record in Central Europe and offers valuable insights into long-term climate variability and its ecological consequences for peatland ecosystems. The results reveal significant changes in peatland wetness and vegetation driven by autogenic processes, climatic fluctuations and anthropogenic influences. Major bryophyte species turnovers occurred ∼11 200, ∼10 350, ∼8200, 7500, ∼5500, ∼600, and ∼450 cal BP often coinciding with declines in Archerella flavum and Hyalosphenia papilio abundances. Both proxies indicate a marked period of drier conditions between ∼ 7600 and ∼ 6800 cal BP corresponding with the Holocene Thermal Maximum. Additionally, testate amoebae data suggest further disturbances at ∼ 3050, ∼ 2000, and ∼ 200 cal BP, and the latter, linked to a permanent shift in species composition, implies lasting changes to peatland conditions caused by intensified human activity. Around the end of the Early Holocene, most species turnovers and disturbances began to align with Holocene Rapid Climate Change (RCC) events.

Monitored seabird populations have declined by up to 70% worldwide since the 1950s, yet little is known about population sizes or long-term trends prior to anthropogenic impacts. This is particularly true for the Southern Ocean, where seabirds and many other species are currently facing multiple environmental threats. Here, we identify shifts in seabird populations over the last 8100 years by applying a mercury (Hg) flux and isotope signature technique as a novel tracer of population size via guano input into peatlands on sub-Antarctic Bird Island (South Georgia). Our results show that seabirds have colonized Bird Island between 6800 and 6100 years ago, which pre-dates evidence for colonization of other sub-Antarctic islands by more than 1000 years. There are five periods when seabird populations were at maxima during the mid- to late-Holocene, coeval with periods of lower Southern Hemisphere westerly wind intensity. Our study provides unprecedented insights into cyclicity in seabird population sizes as a consequence of regional to large-scale environmental change.

This study investigates the vegetation and hydrological dynamics of Linje peatland in northern Poland during the past 11,500 years by integrating testate amoeba and plant macrofossil analyses. The Linje profile is currently the only complete Holocene peat record in Central Europe and offers valuable insights into long-term climate variability and its ecological consequences for peatland ecosystems. The results reveal significant changes in peatland wetness and vegetation driven by 20 autogenic processes, climatic fluctuations and anthropogenic influences. Major bryophyte species turnovers occurred around 11,200, 10,350, 8,200, 7,500, 5,500, 600, and 450 cal. BP often coinciding with declines in Archerella flavum and Hyalosphenia papilio abundances. Both proxies indicate a marked period of drier conditions between 7,600 and 6,800 cal. BP corresponding with the Holocene Thermal Maximum. Additionally, testate amoeba data suggest further disturbances at approximately 3,050, 2,000, and 200 cal. BP, and the latter, linked to a permanent shift in species composition, implies lasting changes to peatland 25 conditions caused by intensified human activity. Around the end of the Early Holocene, most species turnovers and disturbances began to align with Holocene Rapid Climate Change (RCC) events.

This study investigates the vegetation and hydrological dynamics of Linje peatland in northern Poland during the past 11,500 years by integrating testate amoeba and plant macrofossil analyses. The Linje profile is currently the only complete Holocene peat record in Central Europe and offers valuable insights into long-term climate variability and its ecological consequences for peatland ecosystems. The results reveal significant changes in peatland wetness and vegetation driven by 20 autogenic processes, climatic fluctuations and anthropogenic influences. Major bryophyte species turnovers occurred around 11,200, 10,350, 8,200, 7,500, 5,500, 600, and 450 cal. BP often coinciding with declines in Archerella flavum and Hyalosphenia papilio abundances. Both proxies indicate a marked period of drier conditions between 7,600 and 6,800 cal. BP corresponding with the Holocene Thermal Maximum. Additionally, testate amoeba data suggest further disturbances at approximately 3,050, 2,000, and 200 cal. BP, and the latter, linked to a permanent shift in species composition, implies lasting changes to peatland 25 conditions caused by intensified human activity. Around the end of the Early Holocene, most species turnovers and disturbances began to align with Holocene Rapid Climate Change (RCC) events.

This study investigates the vegetation and hydrological dynamics of Linje peatland in northern Poland during the past 11,500 years by integrating testate amoeba and plant macrofossil analyses. The Linje profile is currently the only complete Holocene peat record in Central Europe and offers valuable insights into long-term climate variability and its ecological consequences for peatland ecosystems. The results reveal significant changes in peatland wetness and vegetation driven by 20 autogenic processes, climatic fluctuations and anthropogenic influences. Major bryophyte species turnovers occurred around 11,200, 10,350, 8,200, 7,500, 5,500, 600, and 450 cal. BP often coinciding with declines in Archerella flavum and Hyalosphenia papilio abundances. Both proxies indicate a marked period of drier conditions between 7,600 and 6,800 cal. BP corresponding with the Holocene Thermal Maximum. Additionally, testate amoeba data suggest further disturbances at approximately 3,050, 2,000, and 200 cal. BP, and the latter, linked to a permanent shift in species composition, implies lasting changes to peatland 25 conditions caused by intensified human activity. Around the end of the Early Holocene, most species turnovers and disturbances began to align with Holocene Rapid Climate Change (RCC) events.

This study investigates the vegetation and hydrological dynamics of Linje peatland in northern Poland during the past 11,500 years by integrating testate amoeba and plant macrofossil analyses. The Linje profile is currently the only complete Holocene peat record in Central Europe and offers valuable insights into long-term climate variability and its ecological consequences for peatland ecosystems. The results reveal significant changes in peatland wetness and vegetation driven by 20 autogenic processes, climatic fluctuations and anthropogenic influences. Major bryophyte species turnovers occurred around 11,200, 10,350, 8,200, 7,500, 5,500, 600, and 450 cal. BP often coinciding with declines in Archerella flavum and Hyalosphenia papilio abundances. Both proxies indicate a marked period of drier conditions between 7,600 and 6,800 cal. BP corresponding with the Holocene Thermal Maximum. Additionally, testate amoeba data suggest further disturbances at approximately 3,050, 2,000, and 200 cal. BP, and the latter, linked to a permanent shift in species composition, implies lasting changes to peatland 25 conditions caused by intensified human activity. Around the end of the Early Holocene, most species turnovers and disturbances began to align with Holocene Rapid Climate Change (RCC) events.

This study investigates the vegetation and hydrological dynamics of Linje peatland in northern Poland during the past 11,500 years by integrating testate amoeba and plant macrofossil analyses. The Linje profile is currently the only complete Holocene peat record in Central Europe and offers valuable insights into long-term climate variability and its ecological consequences for peatland ecosystems. The results reveal significant changes in peatland wetness and vegetation driven by 20 autogenic processes, climatic fluctuations and anthropogenic influences. Major bryophyte species turnovers occurred around 11,200, 10,350, 8,200, 7,500, 5,500, 600, and 450 cal. BP often coinciding with declines in Archerella flavum and Hyalosphenia papilio abundances. Both proxies indicate a marked period of drier conditions between 7,600 and 6,800 cal. BP corresponding with the Holocene Thermal Maximum. Additionally, testate amoeba data suggest further disturbances at approximately 3,050, 2,000, and 200 cal. BP, and the latter, linked to a permanent shift in species composition, implies lasting changes to peatland 25 conditions caused by intensified human activity. Around the end of the Early Holocene, most species turnovers and disturbances began to align with Holocene Rapid Climate Change (RCC) events.