From Stranding to Soaring: Leveraging Long-Term Data for Marine Megafauna Conservation

This presentation explores two distinct but complementary approaches to assessing population viability in marine megafauna using long-term datasets. First, I examine common dolphin (Delphinus delphis) population viability trends in the Bay of Biscay using stranding data from 1997-2019, revealing a concerning decline in female lifespan from 24 to 17 years and a 2% decrease in population growth rate. Second, I analyze changes in age at first reproduction of Wandering Albatrosses (Diomedea exulans) on Crozet Islands using a 50-year capture-mark-recapture dataset, uncovering sex-specific trends and environmental influences, including a marked decline in age at first reproduction for both sexes. I then integrate these findings into a broader discussion on marine conservation strategies, focusing on the development and application of removal limit algorithms and harvest thresholds. This research underscores the critical importance of long-term monitoring in understanding population dynamics and demonstrates how diverse data sources can inform effective conservation measures for vulnerable marine species facing anthropogenic pressures and environmental change.