By Alex Kirby
BBC News Online environment correspondent
UK seabirds' breeding attempts in 2004 have been disastrous, the Royal Society for the Protection of Birds says, with industrial fishing largely to blame.
Puffins are among the seabirds to be hit (Image: George McCarthy/rspb-images.com)
In a report the RSPB says 2004 has been the most catastrophic breeding season on record for seabirds along UK coasts.
It says industrial fishing to supply fish meal and oil is barely sustainable and imperils the whole marine food web.
The RSPB says climate change is making matters worse, with some industrial fish species starving as the seas warm.
Industrial fishing catches millions of tonnes of small fish which congregate in dense shoals - species like sandeels, sprats and anchovies - to turn into meal and oil, much of it to feed farmed fish.
The fish caught are a key part of the marine food chain, but the RSPB says we know little about the effects of industrial fishing.
But it is worried: "The UK has suffered serious seabird disasters this year already. In Shetland and Orkney, entire colonies of birds failed to produce any young because of severe food shortages.
"On top of that, hundreds of seabirds have been washing ashore having perished at sea. Again, lack of food is thought to be one of the reasons."
The report, Assessment Of The Sustainability Of Industrial Fisheries Producing Fish Meal And Fish Oil, was compiled for the RSPB by Poseidon Aquatic Resource Management Ltd and the University of Newcastle-upon-Tyne.
It investigated the sustainability of two of the world's largest fisheries, the Peruvian anchovy industry and the North Sea sandeel fishery.
It concluded that industrial fisheries globally are failing to meet crucial criteria for sustainability, with the sandeel fishery deficient on around 60% of the criteria tested.
The RSPB wants more research into the interplay between the fisheries and the marine environment, better stock assessment, regulation, and more efficient management of the industry.
Danish trawler catching sandeels (Image: Chris Gomersall/rspb-images.com)
Dr Euan Dunn, RSPB's head of marine policy, said: "Industrial fishing is straining the bounds of sustainability and simply can't keep up with the enormous future growth in demand for fish feed we anticipate from aquaculture.
"This report demonstrates the urgent need to relieve this 'fish gap' pressure by seeking alternatives to fish meal and oil, such as the development of vegetable substitutes and better recovery of waste from fish caught for human consumption."
Between 17.9 and 39.5m tonnes of fish are estimated to be discarded globally each year by commercial fisheries.
One fish in four worldwide is caught for non-human consumption. World production of fish meal averaged 6.3m tonnes from 1997 to 2000.
A lucky kittiwake chick (Image: Chris Gomersall/rspb-images.com)
Dr Dunn told BBC News Online: "The UN's Food and Agriculture Organisation thinks fish farming will use 50% of the meal and 80% of the oil from the industrial catch by 2010. Industrial fishing will fail to yield enough oil for aquaculture within 25 years.
"This year the European fleet was given a quota of 800,000 tonnes of North Sea sandeels, and managed to catch not much more than 300,000 tonnes.
"The sandeels lack plankton, which are being scuppered by rising sea temperatures. Not only are the plankton species changing, but their seasonal cycle is out of sync with the fish.
"The evidence of a relationship between temperature rise and sandeel survival is becoming very strong indeed.
"The evidence is stronger in the southern parts of the North Sea - climate change is fundamentally altering the food chain.
"We desperately need alternatives to industrial fishing, because we're going to be quite dependent on aquaculture for the next few decades."