Millions of seabirds rely on discarded fish

University of Exeter –

Millions of scavenging seabirds survive on fish discarded by North Sea fishing vessels, new research shows.

University of Exeter scientists estimate that 267,000 tonnes of fish was discarded in the North Sea in 2010 – enough to feed 3.45 million birds. This discard figure is down from almost 510,000 tonnes – enough for an estimated 5.66 million birds – in 1990. Discarding in the North Sea – one of the places in the world with the highest levels of this – is thought to have peaked around 1990.

The study examined eight species, including northern gannets and herring gulls, and the figures are based on birds that rely to some extent on discarded fish (based on observations of how much discarded fish different bird species eat).

“Commercial fishing has a variety of effects on marine life, but the impact of discards is one of the least studied and least understood,” said lead author Dr Richard Sherley, of the Environment and Sustainability Institute on Exeter’s Penryn Campus in Cornwall.

“Our study highlights the sheer number of scavenging birds potentially supported by discards and thus the importance of understanding the wider ecological consequences of dumping fisheries waste.

“With discards declining over the period we studied, the number of birds able to rely on this has also declined.”

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