Wed, Aug 17, 2022: 5:00 PM-6:30 PM
ESA Exhibit Hall
Background/Question/MethodsUnderstanding the long-term histories of seabird nesting colonies can clarify colony dynamics and the drivers of population change. Atlantic Puffins (Fratercula arctica) are listed by the IUCN as a globally Vulnerable species; yet we lack long-term monitoring data to identify the main stressors which contribute to population fluctuations. We used a sediment core from a pond in an Atlantic Puffin colony on an island off the northeast coast of Newfoundland with ~ 15,400 breeding pairs to examine changes in the puffin population since ~ 1730 AD. The beginning of our sediment record coincides with the first permanent human settlement in the area. The area had been used regularly for fishing activities until the moratorium on the Atlantic Cod fishery in the early 1990s. Bycatch of diving seabirds also decreased because of reduced use of gillnets. We are measuring proxies for puffin abundance throughout the sediment core, including sedimentary chlorophyll-a, subfossil diatoms, metal(loid) concentrations, fecal lipids, and stable isotopes of nitrogen (d15N), total carbon (d13C), and organic carbon. Together, these proxies will provide a history of the puffin population at this site over the past 290 years and, we predict, will reflect an increase in the population following the fishing moratorium.
Results/ConclusionsIn comparison to a nearby pond not influenced by seabirds, the puffin impacted pond had lower pH, higher conductivity, and elevated concentrations of dissolved organic carbon, nitrogen, and phosphorus. The puffin pond also had d15N and d13C stable isotope values indicating seabird presence from the beginning of the sediment record, with an increase in abundance around the year 2000. Concentrations of zinc and cadmium, which are often ornithogenically-enriched metal(loids), also increase at the same time. These changes occur a decade after the human use of these islands greatly decreased due to a moratorium on the Newfoundland cod fishery. Our records will help elucidate the main drivers of Atlantic puffin populations and whether these populations can demonstrate resilience to human pressures.
Results/ConclusionsIn comparison to a nearby pond not influenced by seabirds, the puffin impacted pond had lower pH, higher conductivity, and elevated concentrations of dissolved organic carbon, nitrogen, and phosphorus. The puffin pond also had d15N and d13C stable isotope values indicating seabird presence from the beginning of the sediment record, with an increase in abundance around the year 2000. Concentrations of zinc and cadmium, which are often ornithogenically-enriched metal(loids), also increase at the same time. These changes occur a decade after the human use of these islands greatly decreased due to a moratorium on the Newfoundland cod fishery. Our records will help elucidate the main drivers of Atlantic puffin populations and whether these populations can demonstrate resilience to human pressures.