Research provides insight into the history of seabird populations on the Falkland Islands and the potential effects of climate change in the South Atlantic. 

The Falkland Islands, in the South Atlantic Ocean, serve as a critical refuge for a diverse array of wildlife, all thanks to seabird guano. Seabirds only settled on the Falklands within the last 5,000 years, bringing nutrients from the marine environment and driving considerable terrestrial vegetation changes. A paleoecological study led by researchers from the University of Maine traced a 14,000-year history of the islands—identifying direct evidence of this terrestrial-marine link.

Researchers found that 9,000 years ago, the island landscape was dominated by small grasses, ferns, and shrubs. The influx of nutrients from seabird guano transformed the ecosystem into the flourishing coastal grassland and peat-dominated landscape that we see today. They determined that seabird populations were established on the islands during a period of regional cooling, depositing high concentrations of guano and making way for the variety of seabirds that nest on the islands today, including five species of penguins, Great Shearwaters, and White-chinned Petrels. Dulcinea Groff, the lead researcher, says that this terrestrial-marine link is critical for the future conservation of the grasslands, especially as the future of seabird populations remains uncertain in a warming climate.

“Seabird conservation efforts in the South Atlantic should be prepared for these species to move to new breeding grounds in a warmer world, and those locations may not be protected,” explained Groff.

The absence of seabirds prior to the cooling event suggests they may be sensitive to warmer sea surface temperatures due to changes in their food supply. The team notes that as the Southern Ocean temperatures rise, seabird communities could face collapse. Still, since little is known about where seabirds nested before their arrival 5,000 years ago, researchers are unclear what will happen in the face of climate change. 

The research highlights the knowledge gaps that remain as to what might happen to seabirds and grasslands on the Falkland Islands. Tracking these birds’ movements and analysis of fossil records may provide insight into our possible future, as the seabird’s reliance on both land and sea for survival makes them important sentinels of global change. 

Featured photo: A black oystercatcher resting on Carcass Island, Falkland Islands. Credit: Outward_bound
Source: Phys.org