Tag Archives: Prey

Florida’s birds of prey are full of microplastics

A new study from the University of Central Florida (UCF) has found, for the first time, microplastics in terrestrial and aquatic birds of prey in the state.

Image credits Harry Burgess.

Some of the birds in whose digestive systems the team found microplastics include hawks, ospreys, and owls. The accumulation of such material can lead to starvation and poisoning, either of which can be life-threatening. The findings are particularly worrying because birds of prey are critical to a functioning ecosystem, the authors note.

A bird’s gut view

“Birds of prey are top predators in the ecosystem and by changing the population or health status of the top predator, it completely alters all of the animals, organisms and habitats below them on the food web,” says Julia Carlin, the study’s lead author and a graduate of UCF’s Department of Biology.

Microplastics are pieces of plastic that are under 5 mm in length, produced from the breaking down of larger pieces of plastic such as synthetic clothes, or that are purposely-made for use in industry, or for health and beauty products.

Plastic ingestion by wildlife was first noted in the 1960s, the team explains, adding that microplastic ingestion has come under increased scrutiny since 2010. Since then, microplastics have been found in the guts of fish, marine birds, filter-feeding invertebrates such as oysters, and humans.

Birds of prey, however, have not been studied for microplastic ingestion due to their protected status.

For the study, the team worked with the Audubon Center for Birds of Prey in Maitland, Florida where injured raptor birds are nursed back to health. This gave them a unique opportunity to study the stomach contents of 63 birds found across Florida that were dead when they arrived at the center or died 24 hours after they arrived.

Microplastics were found in the digestive systems of all the examined birds, totalling nearly 1,200 pieces of plastic. The most common microplastics found were microfibers (86%), which come from synthetic ropes and fabrics, and can be released into the environment from clothes-washing.

The most common colors seen were blue and clear, which the team says is likely caused by the birds confusing these colors with prey or materials that would be useful for nesting.

As for solutions, the team says removing plastic waste from open landfills (so birds can’t pick them up), retrofitting water treatment installations to capture microplastics, and switching to natural fibers in the clothing industry could all help.

The paper “Microplastic accumulation in the gastrointestinal tracts in birds of prey in central Florida, USA” has been published in the journal Environmental Pollution.

Microplastics.

Microplastics could break down whole ecosystems — they’re making prey unresponsive to predators

Our microplastics are a much more important factor in the health of the ocean than suspected. And they’re up to no good.

Microplastics.

Microplastics.
Image credits Oregon State University / Flickr.

Researchers at the French National Centre for Scientific Research report that microplastics can disrupt predator-prey relationships in the wild. In a new study, the group describes the impact of microplastic consumption on the common periwinkle (Littorina littorea).

Micropastics, macro effects

Periwinkles are a kind of sea snail. They’re not… particularly exciting. They sit on algae-encrusted rocks all day, munching on the plants. They are, however, considered to be a keystone species — they’re prey for many other species, especially crabs (we also eat them sometimes).

The authors wanted to find out what would happen should these periwinkles dine on algae that have absorbed microplastics. Prior research has shown that algae absorbing such products become enriched in hazardous chemicals and metals. Microplastics are porous and soak up these chemicals as they flute around (we’re dumping those chemicals there, too).

Microplastics.

Microplastic beads. They’re quite porous.
Image credits International Maritime Organization / Flickr.

The team’s hypothesis was that when a periwinkle eats the algae, it is also eating the hazardous materials present in the algae. In order to test if this results in any adverse changes for the snails, the team gathered a few periwinkles and brought them into the lab for testing. They also brought along a few crabs to use as predators.

They report that periwinkles which consumed the toxic materials did not react to the crabs in an expected way. Normally, upon spying the predator, the snails pull into their shells or try to hide in the surrounding environment. Those exposed to the toxic materials did not attempt to avoid capture, however, suggesting that they suffered nerve damage of some sort. This is likely due to the ingestion of heavy metals, the team adds.

They note that the levels of toxicity in the microplastics they used for the study were equivalent to those on a typical beach. The findings are thus broadly applicable in real-world conditions — and they point to major changes in the marine environment due to the microplastics we’ve introduced.

The paper “Microplastic leachates impair behavioural vigilance and predator avoidance in a temperate intertidal gastropod” has been published in the journal Biology Letters.