THURSDAY 18 January 2024, 4 PM CET (HYBRID WEBINAR)
Dr. Malte Willmes
Researcher at the Norwegian Institute for Nature Research and affiliated with UC Santa Cruz and the Ronin Institute for Independent Scholarship.
Abstract:
The geochemical analysis of biominerals has revolutionized our understanding of fish life histories, migration patterns, and habitat use. Chinook Salmon are integral to the ecology, culture, and economy in the Pacific, but have experienced drastic declines due to habitat loss and shifting climate regimes. Understanding the life history diversity of the remaining populations is essential for their effective management and conservation.
In this seminar I will describe how we can use sclerochronology and strontium isotope (87Sr/86Sr) analysis of modern and archaeologic fish otoliths (ear stones) to reconstruct movement pathways and key life history traits (age, growth rate, migration size and phenology) of Chinook Salmon in California. The results indicate that there is large variation in habitat use within and among populations both past and present. Based on these findings I argue that maintaining connected and complex habitat mosaics is key to the persistence of salmon populations in the future. The data showcase the pivotal role that geochemical tools can play in aquatic monitoring, habitat restoration, and species recovery.