Energetic impacts of marine heatwaves on seabirds

Marine heatwaves can have significant impacts on marine predators which may reduce their capacity to breed and survive. This is because prey can become scarcer and be of lower energy value during heatwaves. Marine predators, therefore, are working harder to find sufficient prey to feed both themselves and their young. For endangered species, this is particularly worrisome as population numbers will suffer for animals where numbers are already low.

Using kuaka/common diving petrels (Pelecanoides urinatrix), we want to develop a low-cost method of assessing effort in key marine predators to develop an early warning system of trouble. Using doubly labelled water to quantify energetic expenditure, and bird-borne accelerometers to map foraging effort, we want quantify energetic costs of foraging by these birds within the Hauraki Gulf.

From this we will be able to identify how much flying, and diving occurs during heatwaves and what this costs in kJ day^-1. Ultimately, we can then use this to work out 1) how much energy it takes an adult to raise a chick, 2) how much energy the local environment must provide or this to occur, and 3) develop more effective intervention measures for critically endangered species. This will benefit not only seabirds, but also the large marine predators that they associate with. As an understanding of the impacts of heatwaves on energy levels within the broader environment can be gained. 

About the researcher

Brendon Dunphy, Faculty of Science