Ocean plastic plague threatens seabirds

Typography

Already 60% of seabird species have plastic in their guts, often as much as 8% of their body weight. And with ocean plastic increasing exponentially, that figure will rise to 99% by 2050, threatening some birds' survival. Unless we act.

Already 60% of seabird species have plastic in their guts, often as much as 8% of their body weight. And with ocean plastic increasing exponentially, that figure will rise to 99% by 2050, threatening some birds' survival. Unless we act.

Many of you may have already seen the photographs of albatross carcasses full of undigested plastic junk. But how representative is that of the wider issue facing seabirds?

To help answer that question, we carried out the first worldwide analysis of the threat posed by plastic pollution to seabird species worldwide.

Our study, published today in Proceedings of the National Academy of Sciences, found that nearly 60% of all seabird species studied so far have had plastic in their gut. 

This figure is based on reviewing previous reports in the scientific literature, but if we use a statistical model to infer what would be found at the current time and include unstudied species, we expect that more than 90% of seabirds have eaten plastic rubbish.

Our analysis of published studies shows that the amount of plastic in seabird's stomachs has been climbing over the past half-century. In 1960, plastic was found in the stomachs of less than 5% of seabirds, but by 2010 this had risen to 80%.

We predict that by 2050, 99% of the world's seabird species will be accidentally eating plastic, unless we take action to clean up the oceans. Some areas of contain as many as 580,000 plastic pieces per square kilometre.

The surprse - it's worst in the remote Southern Ocean

Perhaps surprisingly, we also found that the area with the worst expected impact is at the boundary of the Southern Ocean and the Tasman Sea, between Australia and New Zealand.

While this region is far away from the subtropical gyres, dubbed 'ocean garbage patches', that collect the highest densities of plastic, the highest threat is in areas where plastic rubbish overlaps with large numbers of different seabird species - such as the Southern Ocean off Australia.

Seabirds are excellent indicators of ecosystem health. The high estimates of plastic in seabirds we found were not so surprising, considering that members of our research team have previously found nearly 200 pieces of plastic in a single seabird.

These items include a wide range of things most of us would recognise: bags, bottle caps, bits of balloons, cigarette lighters, even toothbrushes and plastic toys.

Continue reading at ENN affiliate, The Ecologist.

Seagull with plastic image via Shutterstock.