Wild sea bass are declining so rapidly because of overfishing that catches should be cut drastically, scientists have urged.
The fish, a popular choice in restaurants, has suffered such a dramatic decline in the English Channel, the Irish and Celtic Seas and in the southern part of the North Sea that there are now calls for urgent measures to protect them.
In 2010 the quantity of sea bass at breeding age was 15,000 tonnes, but is now estimated to be 11 to 12,000 tonnes and is expected to fall to 10,000 tonnes in 2015 – the lowest level for 20 years.
Last year scientists called for catches to be cut by 36 per cent but the problem has intensified in the past 12 months and they are now urging an 80 per cent reduction.
The problem is exacerbated by recreational anglers who are responsible for about a quarter of the total landings in the UK, France, Netherlands and Belgium.
Overfishing is cited by the International Council for the Exploration of the Sea (ICES) as a major cause of decline.
Another problem is low recruitment – the shortage of juvenile fish adding to the stock. Scientists say this means the decline in sea bass numbers is likely to continue next year and beyond.
Warmer water temperatures in the 1990s did boost sea bass numbers in UK waters dramatically. But recently, colder winters are thought to have reversed the effect.
Mike Armstrong, a scientist at the Centre for Environment, Fisheries and Aquaculture Science (Cefas), said that in the past 20 years the fishing industry had caught much larger numbers of sea bass.
He said: “Markets have developed and a lot of demand too – everybody wants to eat sea bass. That’s quite a dangerous situation if it means that fishermen try to keep supplying these demands as the stock is declining.
“We need to manage the stock. It’s long-term sustainability that we are about – to the benefit of commercial and recreational fishing.”
ICES scientists said that the total landings last year of 5,632 tonnes – 4,123 tonnes by the commercial fleet and an estimated 1,500 by anglers – must be dramatically reduced. They said the total landings for 2015 must not exceed 1,155 tonnes.
ICES says a management plan is urgently needed to reduce the number of sea bass caught in the wild.
It advises that fishermen need to find ways, such as by using different nets, to reduce the quantity of juvenile sea bass that are caught before they have a chance to spawn and to target adult rather than young fish.
Part of the reason for the demand for a severe cut in the total catch is to bring the sea bass catch in line with the 2002 Johannesburg Declaration commitment by the European Union to reduce catches to sustainable levels by 2015.
Catches of other species have been reduced more gradually over several years but this is the first year sea bass have been fully assessed by ICES.
Extra pressure is believed to have been placed on sea bass populations in the English Channel by French fishermen shifting their attention there from the Bay of Biscay.
Dr Armstrong added that while numbers in the wild are declining, they form only a small proportion of the sea bass eaten in the UK.
Farms in Europe produce more than 50,000 tonnes annually and when other countries such as Egypt are taken into account production exceeds 150,000 tonnes.
In comparison, less than 8,000 tonnes of wild sea bass are in caught Europe.