New guidelines for collecting scat samples from marine predators have been developed to help scientists more accurately identify what they eat.

The DNA metabarcoding method was developed by a team of scientists from the Australian Antarctic Division, the Institute for Marine and Antarctic Studies, and Department of Primary Industries, Parks, Water and Environment, and was recently published in Methods in Ecology and Evolution.

The paper outlines the best procedure for collecting scats of vertebrates, such as seabirds and seals, to provide the most accurate picture of diet.

The non-invasive method recommends collecting fresh scats from adults who are not fasting, avoiding young who do not feed themselves, and reducing contamination from dirt or vegetation.

Lead author of the paper and field biologist, Julie McInnes, said gathering scats from ocean-going animals has always been a challenge.

“Marine predators spend most of the time in the water, so being able to observe feeding events is difficult. However, as seabirds return to land to breed, we are able to get a sample of faeces for DNA dietary analysis,” Ms McInnes said.

“This new protocol will hopefully mean the scats collected on land will be of high quality and reveal more information about what the animals are eating.”

Samples for the project were collected from shy albatross on Albatross Island, off Tasmania’s north coast and the results will be applied to sub Antarctic and Antarctic species.

The Australian Antarctic Division’s ecological genetics group has been instrumental in developing and refining this method.

The Antarctic Division’s Dr Bruce Deagle said understanding the diet of seabirds and seals is important to monitor the impacts of fishing and environmental changes within the marine environment.

“The results of this study are highly valuable for those carrying out DNA dietary studies on all vertebrates, as well as broader studies using DNA analysis,” Dr Deagle said.