Scientists made an alarming discovery about what plastic is most harmful to seabirds. Australia's Institute for Marine and Antarctic Studies discovered that balloons were deadliest. The research team said balloons were 32 times likelier to kill seabirds than hard plastics. They said that while balloons and soft plastics accounted for 5 per cent of plastics ingested, they were responsible for more than 40 per cent of seabird deaths. A researcher said: "Hard plastic fragments may pass quickly through the gut, but soft plastics are more likely to become compacted and cause fatal obstructions."

The study examined 1,733 dead seabirds. Researchers found that over a quarter of the deaths were because of plastic, which is becoming an increasing threat to seabirds. A researcher said: "Marine debris ingestion is now a globally recognized threat.…We suggest that reducing the presence of balloons and balloon fragments in the ocean would directly reduce seabird mortalities." There is 280,000 tons of marine debris worldwide. The researcher said about half of seabirds eat plastic daily. Seabirds will swallow balloons because they think they look like squid.