About 400 vessels from six European nations catch brown shrimp in the North Sea's Crangon fishery, off the coast of Holland.
There is no limit on the amount of brown shrimp that can be caught
Because the rate of catches has been too high, the fishermen have been blamed for the demise of the area's shrimp stocks by retailers.
This has prompted the fishermen to look at becoming accredited under the Marine Stewardship Council's (MSC) eco-labelling scheme.
Mattijs Van der Ploeg owns of a fleet of 40 shrimp boats, which sails from ports in Holland, Germany and Britain.
These boats land about 4,000 tonnes of the shellfish each year - about 12-15% of the North Sea's entire catch.
"In my opinion, when you take a tree from the wood, you have to plant a minimum of one tree back into the wood," he tells Television Trust for the Environment's Earth Report programme.
He says the same philosophy applies to fishing: "If we want to survive, our companies have to do something that keep it sound and well, and that the nature stays how it is."
While there is no limit on the volume of brown shrimp that can be landed, the way it is caught does have an impact on other marine life.
Fishermen have to cut by-catch in order to win an eco-label
Techniques used to catch shrimp also result in other marine life being caught by the shrimpers.
So-called by-catch is dead by the time it is thrown back into the sea.
To address some of the impacts of shrimp fishing, a group of industry representatives and environmentalists have teamed up to look at ways to improve its methods; enough to win certification by the MSC.
"To get its certificate, a fishery has to ensure by-catch is minimised and very, very small," explains Rupert Howes, MSC's chief executive.
"Fisheries are assessed, perhaps to the highest sustainability standard anywhere in the world, by independent third-party scientists.
"Stakeholders are engaged in the process throughout and, in addition, there is a separate peer review by a separate set of scientists of all fishery assessments."
One way to reduce by-catch is by preventing the trawl nets dragging along the sea bed, which is known as bottom-trawling.
However, the first priority identified during a meeting with the MSC was to reduce the catch of "sigsel" - baby shrimp that are too small to eat.
Johan Rispens - a fisherman of 20 years - has made two changes to his boat.
Boat owners agree 'green fishing' is essential for their long-term survival
Firstly, he has fitted a new sieve net that allows larger fish to escape to minimise by-catch.
And he has also fitted a new pipe that has an outlet deeper in the water. This pipe returns live fish back into the water, and the outlet means the fish are returned well beneath the reach of sea birds following the boat.
Mark Nijhof, project manager for Heiploeg, one of two massive Dutch shrimp processing plants, says the MSC label adds a new dimension to his role as quality assurance manager.
"It does not relate to quality as we used to know it," he reveals. "Quality as we used to know it is how it smells, tastes and if it's free of pesticides, heavy metals or dioxins.
"This time, it's not quality that you can measure in a laboratory. It's about the integrity behind the process; the MSC label stands for ecologically sustainable fisheries."
According to the UN Food and Agriculture Organization, half of the world's fisheries are fully exploited, and another quarter is overexploited.
This has led to growing pressure from environmental groups for the situation to be turned round.
"Pressures are both environmental and commercial," says Pim Wisser, director of Den Oever Fish Auction.
Fisherman Johan has modified his trawler to reduce by-catch
"It's the NGOs that start the debate and it's the NGOs that put pressure on supermarkets at the end of the chain; the supermarkets put pressure on the traders, and the traders then put pressure on the fishermen, so it drips down that way."
Rupert Howes says taking the effort to improve fishing practices can make financial sense.
"Some fisheries are actually attracting premiums in the market place for certified seafood over non-certified seafood as global buyers of sea food around the world are paying increasing attention to the environmental provenance and sustainability of the seafood they are buying."
Marc Jansen, head of consumer affairs for the Dutch Retail Association, warns that the costs of improving standards will be passed on to consumers.
"If you go in that direction, the cost in the chain will increase because you have to certify it and people have to look after it and I think the cost will increase and will eventually land with the consumer.
"A lot of consumers are on an average salary and have to take care about where they spend their money and are price-driven."
A fishmonger says customers do care about how fish are caught
Johan Nooitgedart, chairman of the Dutch Fishermen's Union, is also concerned: "I don't think that consumers are really looking for sustainable products compared to the price.
"When something is cheap they like it; then the taste and how it looks are more important than the label, whether or not it is sustainable."
Bart Van Olphen, owner of four fishmonger stores in Holland, begs to differ.
"I get all sorts of customers, and it surprises me because you might think that people with sustainable food wear funny socks, ride funny bicycles and have long hair. But it is all kinds of people that are interested in 'green fish'."
"It is the new generation who are starting to buy quality products - they are very well educated in the ways of sustainability.
"So, I think the new generation is much more informed and they are going to ask for these products."
The Television Trust for the Environment's (TVE) Earth Report - Green Fish - will be broadcast on BBC World on 1-6 February 2008. Please check schedules for further details