In Australia, a new Institute for Marine and Antarctic Studies (IMAS) and CSIRO collaborative study has found that balloons are the highest-risk plastic debris item for seabirds — 32 times more likely to kill than the ingestion of hard plastics.
The researchers looked at the cause of death of 1,733 seabirds from 51 species and found that one in three had ingested marine debris. The data showed that a seabird ingesting a single piece of plastic had a 20 percent chance of mortality, rising to 50 percent for nine items and 100 percent for 93 items.
The study found that although hard plastic accounts for the vast majority of debris ingested it is far less likely to kill than soft plastics such as balloons. Although soft plastics accounted for just five percent of the items ingested they were responsible for more than 40 percent of the mortalities.
Similar research into plastic ingestion by sea turtles has found that while hard plastic fragments may pass quickly through the gut, soft plastics are more likely to become compacted and cause fatal obstructions.