Rune Wikstrom has been fishing in the Baltic Sea for 40 years. He supplies his wife's seafood restaurant at Sollenkroka, 70 kilometres east of Stockholm.
But if he didn't have this local enterprise, Rune knows he would have trouble selling his catch - many of the fish caught in the Baltic have been found to contain excessive levels of dioxins which are thought to cause cancer. The EU has banned sales of the fish abroad.
Like most east-coast fishermen, Rune's main source of income is herring and that is one of the fish most badly affected by the high levels of pollution in the Baltic.
Chemicals in the water are starving fish of oxygen
"The way it affects me is that my equipment and fishing nets are getting very dirty with the increasing amounts of algae that are growing in the water because of the pollution," he says.
"I've noticed that the problem has got a lot worse over the last 20 years and that's obviously very worrying."
The Baltic Sea has been heavily polluted by Russia's coastal cities and those of the Baltic states.
Over the decades, they have poured untreated sewage and chemicals into the water which starve fish of oxygen. Because the Baltic has a sea bed that is full of troughs and ridges, those pollutants are easily trapped.
In the narrow strip of sea which runs between Sweden and Denmark, the water takes 30 years to refresh itself.
And the problem has prompted a national health warning.
Fishermen wanted locals to keep eating fish
The European Union may be allowing Swedish fishermen to continue selling their fish on national markets until the end of 2006, but a condition of this is that health authorities must warn people of the potential risks to their health.
The news came as a shock to Petra Neuman. Eight months pregnant with her first child, Petra used to eat lots of locally caught fish which she bought from her neighbourhood market. Now her diet has completely changed.
"I listen carefully and I try to eat fish from a sea that's not polluted, and [I do not eat] so much fish any more," she says.
Sweden is a driving force at the EU in efforts to clean up the Baltic Sea. But it's a tough battle to win unless every country comes on board.
Swedish Environment Minister Lena Sommestad says that just as they manage to counteract one set of pollutants, new airborne poisons and chemicals are released into the water and the problem never really goes away.
"We've been concerned for a long time," she says.
"We've been working at getting rid of hazardous substances in the Baltic for 20 or 30 years. We've been successful in some cases but new substances occur all the time."
This is small comfort for the Swedish fishermen whose numbers have already been decimated by tighter EU rules on fishing quotas and cuts in fishing fleets.
But Ms Sommestad hopes that other EU regulations will prove to be the saving grace of the Baltic Sea. When Latvia, Estonia and Lithuania join the EU next May, they will also have to start abiding by its strict rules on pollution.
Until then the Swedish public will need a bit of convincing about eating locally caught fish.
In Stockholm's open air museum, which celebrates Swedish traditions and customs, fishermen Rune Wikstrom and his friends have opened a one-day exhibition about the fishing industry.
As he shows the watching crowds how to fillet fish correctly, Rune reminds the onlookers that their national dish is pickled or fried herring.
If they become too cautious about eating it, he warns, then its future - and the livelihoods of the fishermen who catch it - will become increasingly uncertain.
"The risk is definitely being very much exaggerated. Because in my opinion having fish in your diet is healthy - much more healthy than if you were to eat none at all.
Petra Neuman used to eat lots of local fish
"And that's something that never really comes across in the government's warnings and messages."
What will happen to Baltic Sea fishing after 2006 is still unclear.
Environmentalists warn that it is unlikely that dioxin levels will fall significantly over the next few years because the efforts to clean up the water simply do not go far enough.
For fishermen like Rune whose family have drawn their living from these waters for more than four generations, this may well mean his grandsons will have to find themselves a different career.