You know the scene. A commercial fisherman hoists a net roiling with flip-flopping fish. Clouds of seabirds swarm and fill the air with a greedy squawking, their beaks hungry for unwanted catch.
That raucous chorus may get a little quieter soon as birds are forced to seek their feast elsewhere. In a move aimed at curbing the devastating environmental consequences tied to commercial fishing, the European Union looks to consider new restrictions that would ban the discard of unwanted fish. The rule could be a win for fisheries conservation, but in a twist of good intentions, could also risks endangering the gannet, a seabird that thrives on bycatch tossed overboard.
Fisheries have dealt more than one blow to seabird populations as birds compete for resources or risk becoming ensnared in equipment. One of the few successful species, the gannet, has adapted to exploit the leftovers of commercial fisheries, swooping in on fish and other creatures thrown aside and left behind.
Dr. Keith Hamer, a researcher with Leeds’ Faculty of Biological Sciences is leading a team of researchers that will study the gannet and assess the possible consequences of imparting a ban on discarding unwanted catch. “Although discards should be stopped to protect marine biodiversity, research is needed on the impact of a ban, so policy makers can understand the best way to implement it,” said Hamer in a press release.
The study will especially look to better understand how gannets rely on bycatch for raising chicks. Past research indicates that breeding pairs may prefer different menus with some birds relying mostly on discards from fishing boats and others seeking out sand eels or diving for mackerel and herring. “We think gannets have different aptitudes and specialities and for some, that skill might be finding and following fishing boats,” said Hamer.
So if gannets feel like they’re being watched, they’re not so far off. Researchers plan to catch and tag breeding pairs from 12 colonies throughout the United Kingdom. Hamer along with scientists Stephen Votier of the Marine Biology & Ecology Research Centre at the University of Plymouth, and Stuart Bearhop, with the University of Exeter, will keep tabs on the birds’ locations, diving patterns, diet and nests.
“Although the long-term benefits of a ban will be positive, we need to accurately predict short-term impacts as well,” said Hamer. “If gannets have specialised to the extent we believe, rather than cut off a crucial food source overnight, a gradual phasing in of the ban would allow them time to retrain to find food elsewhere.”
Hopefully this thinking ahead will help prevent a new conservation crisis from cropping up even as the EU takes steps to solve another.