Aotearoa seabirds at major risk from plastic pollution
A new study supported by Te Herenga Waka—Victoria University of Wellington demonstrates where seabirds are most at risk from oceanic plastic pollution, emphasising the need for global collaboration to address the issue.
The study, published in Nature Communications, involved more than 200 co-authors, and used data collected by Dr Johannes Fischer as part of his PhD research at the University’s School of Biological Sciences. It was jointly led by Bethany Clark, Ana Carneiro, Elizabeth Pearmain, and Maria Dias from Birdlife International (UK).
Dr Fischer, who now works for the Department of Conservation, says understanding where birds encounter plastic is crucial for understanding risks, targeting research, and designing holistic conservation strategies.
“Plastic pollution harms marine life worldwide, with mounting reports of entanglement and ingestion, but there are large gaps in our understanding.
“Figuring out where the birds are encountering plastic in high levels means we can work out whether they’re ingesting it, and if so how much they’re ingesting, what impact this is having on populations, and design conservation efforts accordingly.”
The team analysed data from over 7,000 individual adult petrels across 77 different species and almost two million locations between 1995 and 2020—one of the largest tracking studies to date. They then weighed the time species spent in specific locations at sea against models of micro- and macro-plastics in the area.
“Using this information, we created an exposure risk score, identifying nineteen species as of particular concern as they’re mostly spending time in areas with above-average plastic density,” says Dr Fischer.
He says the species most at risk are those that use the Mediterranean Sea, the Black Sea, and the north Pacific. These species include the Balearic, Yelkouan, and Newell’s shearwater, as well as the Hawaiian petrel—all threatened by extinction.
“While plastic pollution is emerging as one of the greatest threats to seabirds worldwide, results indicate that the situation in Aotearoa New Zealand is slightly better, as our birds tend not to visit areas with high plastic densities.
“We are particularly relieved that most threatened seabird species that winter in the Southern Ocean—such as Kuaka Whenua Hou Diving Petrels, Chatham Island Tāiko, and Chatham Petrels received very low risk scores.”
Dr Fischer says other birds, though, often do venture into areas with high plastic concentrations.
“Those species that cross the equator on their annual migrations and venture into the north Pacific are at risk. This includes Tītī Cook’s Petrel, Toanui Flesh-footed shearwater, and Korure Mottled Petrel.”
Professor Heiko Wittmer from the University’s School of Biological Sciences, who also contributed to the paper, says mitigating this risk requires a global effort.
“Plastic debris is globally distributed and highly mobile—it crosses political boundaries within and beyond jurisdictions.
“Similar to how we were only able to quantify risks by pooling data from individual studies, we need international cooperation, collaboration, resource mobilisation, and information exchange to address the issue of plastic pollution—through limiting plastic waste production, improving waste management, and cleaning up existing plastic.”
He says such efforts may help safeguard many seabirds from further harm, including those in Aotearoa New Zealand.