Cost effective cetacean spatiotemporal abundance and distribution estimates using data collected from tourist vessels for inclusion in a revised CEMP monitoring program

Baleen whales are important consumers of Antarctic krill, migrating from low latitude breeding grounds to their polar feeding areas each austral spring, however the design and establishment of the CCAMLR Ecosystem Monitoring Program (CEMP) in 1989 has not included ongoing monitoring metrics for baleen whales due to the difficulty and expense of collecting appropriate data.  A pilot study conducted during the austral summer of 2019-2020 to trial the usage of tourist ships as observation platforms successfully demonstrated that intra-seasonal estimates of humpback whale abundances and distributions could be made in this manner. Subsequently, the CEMP Special Fund approved a project to develop this methodology and, providing valuable insights into how a monitoring system should be developed, the sampling effort required and the data that can be collected. Herein we present a short compendium of the work conducted under the CEMP Special Fund project entitled “Developing an at-sea marine mammal and seabird monitoring program in collaboration with the International Association of Antarctic Tourist Operators along the western Antarctic Peninsula”. We show that 12-22 voyages would result in an appropriate volume of data to produce reasonable model-based abundance estimates for baleen whales. We also highlight the utility of tourist vessel-based sampling on spatial and temporal scales relevant to krill fishing management.