A half century of monitoring reveals contrasting survival responses of Icelandic seabirds to climate and fisheries pressures

Seabirds serve as key indicators of marine environmental changes, with adult survival being a critical parameter for assessing population health. Iceland hosts some of the largest seabird populations in the North Atlantic, making it a valuable location for studying long‐term trends in seabird demographics. Using data from a bird‐ringing programme spanning 1974–2021, we estimated adult survival rates for five seabird species – Atlantic Puffin Fratercula arctica , Northern Fulmar Fulmarus glacialis , Black Guillemot Cepphus grylle , Black‐legged Kittiwake Rissa tridactyla and European Shag Gulosus aristotelis – breeding sympatrically in Breiðafjörður, western Iceland. We examined survival over different time periods to explore the potential effects of environmental variability and anthropogenic pressures. Overall, adult survival rates were comparable to those observed in other North Atlantic populations, contrasting with previous findings in other species that indicated higher survival in Icelandic birds. Our results indicated temporal variation in survival for most species, with a notable decline in the late 1990s to early 2000s, followed by partial recovery. This pattern coincided with ecosystem changes, including a collapse of local fish stocks and increased fishing pressures. Species‐specific differences in survival rates over time were probably influenced by variation in foraging ecology and nesting habits, with Fulmars exhibiting the highest survival rates, consistent with their broad foraging range and generalist diet. In contrast, Puffins, Shags and Guillemots, which rely on more localized prey, appeared more susceptible to environmental fluctuations. These findings highlight the importance of long‐term monitoring in understanding the interplay between ecological traits, environmental factors, anthropogenic stressors and seabird population dynamics.