Studying seabirds: recording biodiversity above ocean waves
Seabirds are patchily distributed over the world’s oceans, both in space and time. They are known to favour higher-productivity areas of the ocean such as upwellings, where cold nutrient rich waters are brought to the surface, and oceanic fronts and eddies, where oceanographic processes result in greater prey availabilities for foraging seabirds.
For scientists studying seabirds, this presents a challenge. Such productive ocean areas are often located far from land and far from where most researchers are based.
Over the last 30 years, there has been an increasing use of electronic instruments attached to seabirds to monitor them at sea and away from their colonies on land. However, such remote sensing can only tell scientists so much about how seabirds successfully survive at sea hundreds or thousands of kilometres from their colonies.
One solution to this is observing seabirds at sea from research vessels. This provides researchers with immediate insights into seabird abundance and distribution, as well as marine ecosystems. Seabirds are significantly easier to survey and monitor than other marine life, as they are generally found above the ocean rather than in it (penguins being one exception). Ship-based observation programs are now being used to complement the use of electronic measures.
Despite this, scientists studying seabirds at sea still face a multitude of challenges. Not the least of these are the often-fleeting glimpses of individual birds as they fly between wave crests, only then to reappear 500 metres away from the vessel!
Australia is a global seabird hotspot
Australia’s Exclusive Economic Zone (EEZ) supports approximately 140 of the world’s 340 species of seabird. More than one third of the world’s seabirds breed, feed, fly or swim (in the case of penguins) through our EEZ at some time every year. Australia’s EEZ is a marine biodiversity hotspot. It spans sub-equatorial waters, which includes gregarious seabird species such as the Red-footed Booby and Lesser Frigatebird, to the temperate zone, with whirling Grey-faced Petrels and Fairy Prions, to sub-Antarctic waters, where one of the world’s largest flying birds, the Southern Royal Albatross, is found along with the tiny Wilson’s Storm Petrel (weighing only 50g).
In 2016, the Australasian Seabird Group (ASG), a Special Interest Group of BirdLife Australia, initiated a long-term project to survey seabirds and marine mammals around Australia. This was made possible with support from the CSIRO Marine National Facility (MNF), operator of research vessel (RV) Investigator.
Through grants of sea time on voyages, the ASG project collects crucial data about the distribution and abundance of seabirds throughout the Australian EEZ and beyond. The project offers a value-add to voyages and supports the MNF objective of maximising use of berths in the voyage schedule. The project contributes to the highly collaborative and multidisciplinary nature of marine research delivered by the vessel, providing further diversity in science disciplines and discussions on board.
Using ships of opportunity to fill data gaps
Since late 2016 and pre-pandemic, the project has undertaken surveys on 13 voyages of RV Investigator, with future voyages in the pipeline. The project uses international standard methods to collect seabird at-sea observations.
To date, the project has collected more than 12,000 records of 112,000 birds from 120 species collected over 200 days at sea.
Importantly, the project has collected extensive new data for seabirds for which there are very few (and in many cases, nil) previous data. This is addressing fundamental gaps in our knowledge of the at-sea distributions of seabirds around Australia. Seabird observations are collected alongside physical, chemical and biological oceanographic data constantly sampled by RV Investigator while underway. Scientists use this suite of data to assist their understanding of the way in which seabirds relate to the dynamic and changing ocean environments.
Seabirds as an indicator of ocean health
The ASG effort builds on a substantial data set compiled by an Australian Antarctic Division project in the Southern Ocean from 1980–2006. All other available historical data from 1947–2012 (from various sources around Australia) have also been compiled. As of June 2020, the data set contains more than 300,000 seabird records.
It is the largest and longest time-series seabird at-sea data set in the world.
This data provides much more information than just the distribution and abundance of seabirds. Seabirds obtain all their food from the sea so provide important insights into the health of marine systems for researchers and marine managers. Individuals of many species are long-lived – albatrosses may live more than 60 years – so long-term data sets are critical to understanding the signals that seabirds offer about the marine environment.
The ASG project is collaborating with researchers and marine managers from CSIRO, Parks Australia, Geoscience Australia and numerous universities in Australia and New Zealand who share and benefit from these data. The project is supported by grants of sea time on RV Investigator from the CSIRO Marine National Facility and funding from Parks Australia.
Find out more about the seabird and marine mammal research project.