Rising demand for bycatch will lead to ‘ecological catastrophe’, scientists warn

Bycatch, low-value fish caught unintentionally by indiscriminatory trawling nets, has traditionally been thrown back into the sea.

But now developing markets for bycatch, coupled with increasingly unprofitable shrimp catches, are threatening to push fisheries to extinction, spelling disaster for marine ecosystems and fishermen, according to research published in the journal Conservation Letters.

Shrimp fishermen in south and southeast Asia are trawling for longer hours and in more areas, said the authors, to boost their dwindling income by selling their bycatch for poultry feed, aquaculture and local consumption.

Shrimp trawling generates more bycatch than any other type of fishery, with up to 10kg of bycatch captured for each kilogram of shrimp.

But the study's authors warn, ‘If appropriate measures are not taken immediately to limit overfishing then the outcomes could be catastrophic for the ecosystem and result in the permanent loss of livelihoods for the fishers in the region.’
 
Environmentalists have campaigned for years about the wastefulness of bycatch but have questioned the viability of prolonged trawling to supply a bycatch market.

‘On the surface, utilising bycatch species is of course a good thing,’ said Willie McKenzie, Oceans Campaigner for Greenpeace. ‘But in reality we should be developing more selective and specific ways of fishing.

‘Commodities like shrimp and salmon have gone, in just a couple of decades, from being luxury food to cheap, undervalued food. It is this cheapness that has been the real driver to find economic value in the bycatch.’

‘While a commercial market for bycatch may make a fishery economically viable,’ said Toby Middleton, UK Country Manager of the Marine Stewardship Council, ‘if that bycatch is based on fundamentally unsustainable fishing practises then that leaves question marks over the long term viability of that fishery, either economically or environmentally.’

Useful links

The study in Conservation Letters

	READ MORE...
	HOW TO MAKE A DIFFERENCE How to protect UK rivers from invasive mitten crabs, and eat locally as well! Chinese mitten crabs are pushing indigenous species out of UK rivers and damaging river banks and habitats. It's time to look at how we could control them, and maybe find a new seafood delicacy to boot
	INVESTIGATION Eating insects: a solution to the meat problem? The world's demand for protein will continue to rise, even as the environmental impacts of meat production become clearer. Could turning to commonly eaten insect species be the answer?
	NEWS Cloned animals a 'threat to genetic diversity' Report highlights the danger of cloning to animal health as campaigners also warn it will reduce genetic diversity within herds
	NEWS Marine food chain hit by ocean global warming The entire marine food chain is in danger of collapse because of a decline in tiny phytoplankton, which scientists are linking to climate change and rising ocean surface temperatures.