Recovery status and ecology of fin whales (Balaenoptera physalus) at the West Antarctic Peninsula
Dr. Helena Herr
Centrum für Naturkunde (CeNak)
This project aims to (1) quantify the recovery status of fin whales at the West Antarctic Peninsula (WAP), (2) determine ecological relationships between fin whales and different krill species at the WAP and (3) identify migratory pathways to potential breeding grounds. Fin whales of the Southern Hemisphere were reduced to 2% of their pristine population size during the times of commercial whaling. Their recovery status is unknown, and information on migration routes and distribution patterns is lacking. Recently, high sighting numbers of fin whales at the West Antarctic Peninsula (WAP) have been reported, indicating a return of fin whales to this area. Historical catch records suggest that this region was a prime feeding habitat of fin whales before the over-exploitation by commercial whaling. The WAP is known for extremely high krill biomass, supporting high predator densities, including many species of baleen whales that perform seasonal migrations to Antarctic waters to feed on krill. Currently, the WAP ecosystem is changing rapidly, with pressures arising from climate change, ocean acidification and the expanding krill fisheries. This may have profound effects on the marine food web and may impact the abundance of krill and krill-dependant predators, as well as the ecological interactions among them. Changes in the species composition at the WAP may have influenced the newly observed fin whale occurrences. However, increasing fin whale numbers may also be indicative of a recovering population or of a large-scale distributional shift.In this project, we will investigate the ecological drivers of fin whale distribution along the WAP. We will determine, if increasing densities are related to population recovery or a distributional shift, with a special focus on the role of prey species composition and climate related changes in the WAP ecosystem. Robust estimates of abundance will provide information on fin whale densities. These densities will be related to habitat parameters, specifically krill distribution, to identify ecological relationships. Finally, identification of migratory pathways will provide information on origins of the fin whales at the WAP, potentially even breeding grounds. To achieve these objectives, standardised whale and krill surveys will be conducted concurrently at the same temporal and spatial scale. In addition, fin whales will be equipped with satellite tags. Obtained distribution patterns of fin whales and different krill species will be statistically compared for spatial overlap and association using modelling tools. Tracking data will be used to determine migratory pathways and to deduce migratory origins. This study is to be the first to investigate the return of fin whales to the WAP, an area currently experiencing very rapid climate induced environmental changes.
DFG Programme: Infrastructure Priority Programmes
Term since 2018