Manx shearwater in flight over the Celtic Sea. Manx shearwaters are a seabird species at risk from oil pollution, as they spend most of their lives at sea, and much of that time on the water’s surface. Credit: Jamie Darby, School of Biological Earth and Environmental Science, UCC
Small amounts of crude oil on the surface of the water, less than one percent of the thickness of a hair, can damage the feathers of seabirds, according to a study from University College Cork (UCC).
Researchers from the Marine Ecology Group at UCC in Ireland collected feathers from Manx shearwaters, a seabird species believed to be at risk from oil pollution. The researchers examined the springs to see how quickly water would pass after exposure to increasing concentrations of oil. Feathers were also assessed under high-powered microscopes to examine post-contamination structural changes.
This study found that extremely thin oil sheen, between 0.1 and 3 micrometers thick, was sufficient to have a significant effect on feather structure and affect watertightness. Seabirds exposed to oil are more likely to become drenched, cold and less buoyant, other studies have shown.
Oil damaged Manx shearwater feathers under a digital high power microscope. The microstructure in the spring clumps together after exposure to oil, allowing water to pass more easily. Credit: Dr. Richard Unitt, School of Biological Earth and Environmental Science, UCC
Unrefined oil (crude oil) has been known to spill into the sea in large quantities as a result of disasters such as the Exxon Valdez and Sea Empress spills. It is also routinely released into the environment in moderate amounts as a result of extraction and transportation activities. Oil pollution poses a significant threat to many already endangered seabird populations.
Oil damaged Manx shearwater feathers under a digital high power microscope. The microstructure in the spring clumps together after exposure to oil, allowing water to pass more easily. Credit: Dr. Richard Unitt, School of Biological Earth and Environmental Science, UCC
Emma Murphy, lead author of the study, said: “Chronic small-scale oil pollution is often overlooked in the marine environment, although it has been shown to seriously affect the fitness and survival of seabirds. This study examined one species, but the results could be extended to other species that rely on waterproofing to stay healthy when at sea for long periods of time.”
Even when oil is released in moderate amounts from the extraction and transport infrastructure, oil can spread over the sea surface quite quickly, and a fairly large sea area can be covered with oil in concentrations that can be harmful to seabirds.
The study appears in Royal Society Open Science.
Climate change could make it harder for seabirds to feed, study finds
Light to medium oil sheen increases the permeability of Manx shearwater feathers, Royal Society Open Science (2022). DOI: 10.1098/rsos.220488. royalsocietypublishing.org/doi/10.1098/rsos.220488
Quote: Only a small amount of oil damages seabird feathers, study finds (2022, Oct. 4), retrieved Oct. 4, 2022 at https://phys.org/news/2022-10-tiny-amount-oil-seabirds- feathers.html
This document is copyrighted. Other than fair dealing for personal study or research, nothing may be reproduced without written permission. The content is provided for informational purposes only.