Multicentury perspective assessing the sustainability of the historical harvest of seaducks

Abstract

Where available, census data on seabirds often do not extend beyond a few years or decades, challenging our ability to identify drivers of population change and to develop conservation policies. Here, we reconstruct long-term population dynamics of northern common eiders (Somateria mollissima borealis). We analyzed sterols together with stable nitrogen isotopes in dated pond sediment cores to show that eiders underwent broadscale population declines over the 20th century at Canadian subarctic breeding sites. Likely, a rapidly growing Greenland population, combined with relocation of Inuit to larger Arctic communities and associated increases in the availability of firearms and motors during the early to mid-20th century, generated more efficient hunting practices, which in turn reduced the number of adult eiders breeding at Canadian nesting islands. Our paleolimnological approach highlights that current and local monitoring windows for many sensitive seabird species may be inadequate for making key conservation decisions.

Integrative analysis of DNA, macroscopic remains and stable isotopes of dog coprolites to reconstruct community diet

“…Coprolites can contain organic matter that can be used in radiocarbon dating to determine when an archaeological site was occupied 7 – 10 . The stable carbon and nitrogen isotope composition (δ 13 C and δ 15 N) of feces and coprolites can also be used to reconstruct diet isotopic composition 11 – 15 , and ancient bat guano and soil samples that likely contain fecal matter have been used to identify changes in climate, population demographics, and diet 16 – 19 .…”

Striking centennial-scale changes in the population size of a threatened seabird

“…The validity of the palaeolimnological methodology has been confirmed by numerous palaeoreconstructions of seabird population dynamics (e.g. [4,23,24]). In our study, we build on previous palaeolimnological work by providing six independent proxies of the Leach's Storm-petrel colony's dynamics to help place recent declines in the context of potential long-term population drivers.…”

“…To disentangle the natural range of population variability from relatively recent anthropogenically driven declines, long-term ecological and environmental studies are required. For example, long-term studies have been successfully applied in the restoration of natural wolf and moose populations on Isle Royale [2], understanding fish stock abundance in the face of changing climate [3], and declining Common Eider populations due to the growing availability of firearms and outboard motors in Greenland [4]. Unfortunately, despite general acceptance of the importance of long-term monitoring for conservation in the face of human influences, their presence in the research literature is declining [5].…”

Seaduck engineers in the Arctic Archipelago: nesting eiders deliver marine nutrients and transform the chemistry of island soils, plants, and ponds

“…Thus common eiders in the circumpolar Arctic may transport marine-derived nutrients from productive coastal waters (Tremblay et al 2012 ) to the severely nutrient-limited terrestrial environment of their Arctic colony islands. Such marine-derived nutrients are likely to accumulate as eiders show a high degree of philopatry to nesting sites (Goudie et al 2000 ; Hargan et al 2019 ). This deposition of nutrient-rich eider guano has been shown to increase nutrient concentrations in freshwaters adjacent to eider colonies (Michelutti et al 2010 ; Duda et al 2018 ; Hargan et al 2019 ).…”

“…Such marine-derived nutrients are likely to accumulate as eiders show a high degree of philopatry to nesting sites (Goudie et al 2000 ; Hargan et al 2019 ). This deposition of nutrient-rich eider guano has been shown to increase nutrient concentrations in freshwaters adjacent to eider colonies (Michelutti et al 2010 ; Duda et al 2018 ; Hargan et al 2019 ). In general, most seabird bio-vector studies have generally focused on small geographical areas with the study boundaries limited to one large seabird colony (> 10,000 nesting pairs) and the immediate adjacent aquatic and terrestrial environment (Keatley et al 2009 ; Wright et al 2010 ; Hargan et al 2017 ).…”