Birds and plastic pollution

The world makes up to 400 million tonnes of plastics every year, and maybe as much as 10 per cent of that ends up in the world's oceans where it constitutes most of the marine debris found on the surface and in sediments. Seabirds are particularly vulnerable to the effects, and, as a result, are driving policy decisions, as, speaking with Chris Smith, Birdlife International's Bethany Clark explains...

Bethany - The main point of the work was to look at how seabirds are informing global policies on plastic pollution, how they can be used as monitors for plastic pollution, and also how we can conserve seabirds on a global scale.

Chris - Plastic is a massive problem, isn't it? I mean, the amounts that are out there are truly staggering.

Bethany - Yes. And we don't actually know how much is out there. It's been found in every ocean seabeds travel for thousands of kilometres and wherever they go, they seem to be able to pick up plastics somewhere.

Chris - Is that as in macro-plastic, big bits we can see or is it the microplastics that those big bits break down into, or is it both?

Bethany - It's both. So really large plastics can be a problem for entanglements. Microplastics are also a problem if they ingest them, they can carry toxic chemicals and cause physical scarring to the guts.

Chris - And how is this analysed then? So if you are using birds as, it's like a canary in the coal mine, but for plastic, isn't it slightly warped analogy, but how do you use the birds to keep tabs on what is happening with the plastic?

Bethany - A number of studies around the world have looked at the diets of seabirds, chemical contamination in their blood or feathers. And so that we can assess whether particular populations have a, a high or low plastic contamination. We can then combine that with where the birds travel and match that up to figure out which areas of the ocean are more or less contaminated.

Chris - But if the birds are themselves being impacted, is there a chance you can miss quite a lot of data? Because if the birds are already dead because it's so bad for them, or it's affecting their behaviour, you wouldn't know...

Bethany - Yes. And also if the seabirds are affected by other threats like climate change, fisheries or invasive species, then we are losing that ability of the birds to tell us about where plastic and other types of pollution are in the oceans.

Chris - How did you pursue this study?

Bethany - In this study we assessed all of the different global and quite a lot of regional policy mechanisms that we could find that were related to seabirds or plastics or both to try and find the linkages. So which treaties were signed by countries in forums like the UN that relate to environmental pollution and how seabirds are really used as monitors or seabird conservation as part of agreements to protect nature.

Chris - And what emerged?

Bethany - We found that quite a few of the treaties did mention seabirds or plastic, but there are quite a few opportunities for linking those more specifically. And there's an upcoming treaty on plastic pollution that's going to be negotiated in the next year or so. And a recent treaty that's just been signed for protection of biodiversity on the high seas, which is a lawless environment where a lot of things, including pollution exist, but there's very little collaborative conservation work out there. So we're trying to suggest areas where those gaps can be filled.

Chris - I'm glad you brought that up because one of the, the things about water is it covers three quarters of the surface of the planet in our oceans and it's everywhere. The plastic problem is everywhere. Marine conservation needs to be everywhere but isn't. So if we got gaps in what we do and don't know, are there, are there sort of known unknowns if you like?

Bethany - Yes, definitely. Some of those gaps have been filled in by tracking seabirds, using small devices to follow where they go around the world. But that research is more common in some places than others. And also the study of what the birds have ingested is more intensive in some places. So the Pacific has some of the biggest gaps. It's a really important place for seabirds, but there's less research.

Chris - So is this one of the things on your wishlist, one of the conclusions you draw that that we need to fill those gaps in?

Bethany - Yes. I think standardised monitoring globally is is a major gap that we'd like to fill in or suggest that anyone else joins with that.

Chris - And were there any other really obvious take home messages that emerged when you think these are things we absolutely need to dwell on once you began to look at this in this joined up way?

Bethany - Yeah, so I think a main issue that has come from this is that the seabirds don't they don't follow any kind of borders, jurisdictions. They travel all over the world, but so does plastic. So any plastic waste that comes from any particular country can travel all across the world in ocean currents. And so we really need this to be a global scale, international project to fix this because it can't be done by any single country or or region.