Overfishing of EU fisheries is costing £2.7bn (3.2bn euros) a year and 100,000 jobs, a report has said.
The research, by the UK-based New Economics Foundation, said a third of Britain's fish consumption could be met if stocks were allowed to recover.
Separate research suggests that half of fishermen would not be willing to give up their livelihoods.
Last week, a report said there were reasons to be optimistic that fisheries could recover from past exploitation.
"Overfishing is bad for the economy," said report author Rupert Crilly, environmental economics researcher for the foundation's Ocean2012 initiative.
"With the stroke of pen, European fisheries ministers are wiping out millions of pounds and thousands of jobs each year by allowing overfishing to continue."
The report, Lost at Sea, concluded that the restoring 43 of the continent's fish stocks to their "maximum sustainable yield" (largest annual catch that can be maintained over the long term) would result in an additional 3.5m tonnes of fish reaching markets, "enough to meet the annual demand for almost 160m EU citizens".
It added: "Overfishing is the single most destructive force in the marine environment.
"It has made the fishing industry economically vulnerable and caused coastal communities to crumble. Instead of rebuilding (fish) stocks, the industry has become heavily subsidised by the taxpayer.
"This is a losing battle. In just these (43) sample stocks, the cost of overfishing is five times higher than the value of EU subsidies."
It warned that the proposed reforms to the 27-nation bloc's Common Fisheries Policy did not go far enough to address the problem.
"Restoring fish stocks is within politicians' power, and in the current economic climate, the stakes are higher than ever," Mr Crilly said.
Last week, the Prince of Wales launched a report by his think-tank, International Sustainability Unit (ISU), that looked at a way to put fisheries around the globe on a sustainable footing.
The report, Fisheries in Transition, concluded that by regulating the catch in a sensible way, fishermen were able to make more money for less effort, allowing the stock to be safeguarded against exploitation.
"We recognise that there is no 'one size fits all', solution - every fishery is different," said Charlotte Cawthorne, ISU marine programme manager, speaking at the report's launch.
But, she added, three things were essential: scientific understanding of the ecosystem, funding for the transition, and sound management.
A study published this week in the journal Plos One said that half of the fishermen in developing nations would not be willing to give up their livelihoods, regardless of declining catches.
"We found that half of fishermen questioned would not be tempted to seek out a new livelihood, even if their catch declined by 50%," said co-author Dr Tim Daw from the University of East Anglia.
The survey carried out by an international team of researchers questioned almost 600 fishermen in Africa and Asia about how they would respond to declining catches.
"Surprisingly, fishermen in the more vibrant and developed economies were less likely to give up their trade, despite having more economically fruitful opportunities open to them," explained fellow co-author Joshua Cinner from the ARC Centre of Excellence for Coral Reef Studies, Australia.
"This is the reverse of the common belief that poor communities are less likely to adapt than wealthy ones," Dr Cinner added.
"We suspect that this may be in part due to the perverse impacts of subsidies in more developed countries encouraging people to stay in the fishery which would otherwise not be profitable."