Incidence of marine debris in seabirds feeding at different water depths

- We examined the incidence of debris in the digestive tracts of 22 seabird species.
- 55% of the species, corresponding to 16% of all individuals, contained debris.
- The incidence of debris was higher in birds feeding below the ocean surface.
- Our results highlight the tri-dimensional distribution of debris in the ocean.

Marine debris such as plastic fragments and fishing gears are accumulating in the ocean at alarming rates. This study assesses the incidence of debris in the gastrointestinal tracts of seabirds feeding at different depths and found stranded along the Brazilian coast in the period 2010-2013. More than half (55%) of the species analysed, corresponding to 16% of the total number of individuals, presented plastic particles in their gastrointestinal tracts. The incidence of debris was higher in birds feeding predominantly at intermediate (3-6 m) and deep (20-100 m) waters than those feeding at surface (< 2 m). These results suggest that studying the presence of debris in organisms mainly feeding at the ocean surface provides a limited view about the risks that this form of pollution has on marine life and highlight the ubiquitous and three-dimensional distribution of plastic in the oceans.