Southern Hemisphere humpback whales under future climate scenarios
Whale biology, ecology and behaviour – including the patterns of migration, feeding and breeding – are subject to many direct and indirect impacts from climatic variability and human-forced global climate change. Understanding the influence of current and future climate on whales, therefore, requires research into the key components of the humpback whale life cycle and how these interact with their biophysical environment and human impacts. We are developing a conceptual framework of this as the basis for our quantitative modelling (Figure 1).
Figure 1. High level conceptual framework for the humpback whale system. Boxes indicate key system variables, with climate change (orange) affecting ocean and atmosphere components (purple). Together with anthropogenic activities (rose), these impact on aspects of humpback whale ecology (blue).
Unpacking this conceptual framework into a working model will require integration of data and functions from all the other project themes in order to gain a comprehensive understanding of humpback whale potential responses under future climate scenarios. This integration will be accomplished through a coupled modelling approach, consisting of a variety of sub-models that provide information on essential parameters (e.g. oceanographic models providing the 3D flow environment and sea surface temperature changes) together with a behavioural simulation model that quantifies the subsequent response of humpback whales to their environment. The end-product will be calibrated at a range of spatial and temporal scales, including climate forcing. Model outputs will be validated with existing databases of humpback whale migration routes or other trajectories before being applied under future climate change scenarios and evaluating the results.
Figure 2. Seasonal dynamics of Antarctic sea ice simulated for 2009/2010. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.
The main research objective in this theme include:
- Determine the behavioural response of humpback whale behaviour to selected environmental parameters;
- Develop and calibrate an integrated coupled model for humpback whales; and
- Simulate and validate humpback whale movements under present and future climate scenarios.