Peter Ellis at the dock in Newhaven

At a time when many of us worry about what sort of fish we should be eating, one Californian reader kindly sent me the exemplary menu from a special seafood dinner held at Oliveto restaurant in Oakland.

It’s a fine example of a restaurant taking great care: each fish on the menu is cross-referenced to a list of 29 sources and harvest methods, from Boston mackerel (caught by traps off Rhode Island) to tai snapper (caught by hook and line in New Zealand).

I sent the menu to Charles Clover, whose book The End of the Line (now an excellent film) highlighted the overfishing crisis and exposed many leading chefs’ indifference to the issue. It was “a menu from the future, information-wise; shame about the halibut and swordfish”, he replied. Atlantic halibut, he said, is an endangered species, while swordfish is a top predator, whose demise affects the entire fish population – and it is liable to overfishing.

I could not help thinking that if even the most environmentally-aware restaurant can make mistakes about the fish it serves then the general lack of knowledge surrounding this topic must be vast.

To find out more about the fish supplied to restaurants, I went to Newhaven Harbour on the south coast of England, to visit the headquarters of Network Seafoods and to meet Peter Ellis, its founder.

Ellis, 63, began his fishing career by building a boat to catch tuna off the south-west coast of Ireland but for the past 30 years he has been a buyer, processor and distributor, not just to the restaurants that his vans visit once he has bought the fish every morning on Newhaven quayside, but also to supermarkets and the National Health Service.

He explained what has changed in recent years: “Our business used to be simply supplying the freshest, whole wild fish, which we cleaned, to the kitchens. But as the number of experienced sous-chefs who can fillet a fish has been cut significantly, restaurants now demand that their fish are delivered ready-filleted and boxed in just the right kind of ice, neither too lumpy nor too coarse – whisky-friendly ice, I call it. And we do all that for them downstairs. We keep the fish bones and give them away to our best customers so they can still make a proper bouillabaisse.”

Dwindling fish stocks mean Ellis has to supply farmed fish alongside wild, but this is a matter of principle as well as business. His company won’t sell wild salmon any longer because he considers it an endangered species. Ellis also handles farmed turbot and sea trout from the Shetland Isles and his verdict is that the farmed variety is “not bad at all”. His farmed salmon comes from Norway.

But the two farmed fish that most impress Ellis are sea bass from Greece and Turkey and trout from a farm on the river Avon in Hampshire, where the fish are forced to swim against the river’s current, which improves their flavour.

Our conversation turned to cod and Ellis said that he found it “absolutely galling” that he has to import farmed cod from Norway when stocks in UK waters used to be so abundant. “We gave away our fishing rights when we joined the EU,” he explained. “The rules governing what can be landed here are much stricter than they are on the other side of the Channel.”

As we parted, Ellis told me why the past 40 years have been so rewarding. “I’m not selling fish but seafood,” he said. “The spectrum of flavours that comes from what’s in the sea, lakes and rivers is much broader than the range of meat that’s available. We just have to try and price it sensibly for the next generation to enjoy.”

Oliveto, www.oliveto.com
‘The End of the Line’, www.endoftheline.com
Network Seafoods, www.networkseafoods.co.uk

nicholas.lander@ft.com
More columns at www.ft.com/lander