NORTH SEA FISH CRISIS - part 1

Overfishing in the North Sea now threatens the entire marine ecosystem and since the 1990s has placed virtually all commercial fish species, including cod, hake, herring, haddock, mackerel, plaice, saithe, and whiting at dangerously low levels and at risk of stock collapse.

Were you asked to identify some of the most remarkable wildlife areas in the world, the chances are that you would list the tropical rainforests, the savannas of Africa, coral reefs or the Antarctic. What we all tend to forget, overlook, or take for granted, is one remarkable area right on our doorstep - The North Sea.

The North Sea is an extraordinary natural phenomenon. Warm ocean currents cross the Atlantic, keeping it free of the ice that would normally lock up a sea at this latitude for much of the year. Coastal rivers have historically delivered just the right amount of nutrients - neither too much or too little - to create an extremely productive system. The shallow waters of the North Sea have assisted in this process.

A diverse and extremely productive ecosystem has developed in these conditions. Plant and animal plankton of surreal beauty grow in profusion. They in turn provide food for over 200 species of fish. At the top of the food web are seals, porpoises, and dolphins, as well as leviathans such as Orca, minke and fin whales that, usually unnoticed go as they swim just offshore from some of the most industrialised parts of the planet. Around the sea's margins the abundance of life on rocky shores and shimmering mud flats attracts vast numbers of birds, including migrants from the Arctic, Antarctic and the equator, giving the North Sea truly global importance.

Nevertheless the North Sea is today only a shadow of what it once was, and what it can become. In the fourteenth century, right whales still swam in the Channel. In the middle ages London apprentices are reputed to have rioted, complaining of their monotonous and cheap diet of salmon. Large sturgeon migrated up the rivers to spawn, where they were frequently caught as recently as the last century. Cod grew to full age, a length of over 2 metres, and a weight of 90 kg (200 pounds). They and herring were of legendary abundance; the Scottish fishers alone, with their small boats and simple nets, were landing three quarters of a billion of each species little more than a hundred years ago. In the 1920s and 30s huge halibut and skate were still being caught, that had to be individually winched off the boat's deck with a crane. Tuna were still present, feeding on the herring, in large enough numbers to support a fishery until the mid-1960s.

1938 - World record Tunny catch. Blue Fin Tuna caught off the Dogger Bank, in the North Sea. In 1953, it was estimated that 3-4000 tunny were caught, since then tunny has diappeared from the North Sea.

Fish such as herring and pilchard, have always been notorious for their fickle nature, shifting their grounds or even disappearing from view, disrupting local fishing communities. But the pace of change has accelerated. The size of fish being landed is going down, and fishing boats have to go further afield for their catches. North Sea mackerel and herring stocks collapsed in the 1960s and 1970s. The mackerel never recovered. Herring did, only to fall to dangerously low levels again in the 1990s. The same fate has met virtually all other commercial fish species, including cod, hake, haddock, mackerel, plaice, saithe and whiting. According to the latest (intrinsically over-optimistic) official assessments, haddock and possibly whiting and saithe may have gained a breathing space, but the overall situation remains grim.

THE IMPACT OF FISHERIES

The deterioration of the North Sea has many causes, from land reclamation stretching back hundreds of years, to pollution during the later part of this century. But fishing has been by far the most significant. For issues such as pollution there is often heated debate about the extent of its effects. For fishing there is no dispute; each year fishing in the North Sea now kills billions of fish, threatening the entire ecosystem. People have always striven to find easier and more effective ways of doing things. Fishing is no exception.

The major changes have come in the space of little more than a century. Most significant was the arrival of first steam and then diesel power. This in turn allowed trawling, which requires a large amount of power, to be developed and used effectively for the first time. A second change, gaining speed in the last 40 years, has been the use of ever more powerful sonar and other electronic aids which have allowed fishers increasingly to remove the guesswork. Finally there has been the disastrous implementation of fisheries policies that ignore natural biological constraints. Together these have created short term gains. But this is at an enormous and escalating cost to the marine environment and fishing industry itself.

INNOCENT CASUALTIES

Methods such as beam trawling, principally carried out by the Dutch, where heavy gear is dragged over the seabed are immensely destructive to life on the seabed, such as shellfish, worms and brittlestars which - while not the most glamorous of species - are vital parts of the marine ecosystem. Each sweep appears to kill between 15 to 55% of the animals, depending on the species. Fishing is so intense in the southern North Sea that, on average, any one area is likely to be swept by gear between one and four times each year. Certain habitats, such as the fragile tube reefs built up by serpulid worms, which provide an important habitat full of nooks and crannies for other species, have been wiped out by such fishing methods. In the early 1990s a research team intending to compare undisturbed and trawled areas in the south-eastern North Sea was unable to find any untrawled areas.

Up to 7,000 porpoises are killed in the North Sea each year due to destructive fishing practices. Death on this scale could be as significant as for the dolphins in the tuna fisheries during the 1980s.

Birds may also be affected by fishing in several ways. They get caught in nets, particularly fixed nets and abandoned gear. There is also concern about the possible effects of industrial fishing, which takes the same fish that the birds feed upon. In recent years the industrial fisheries have been moving into areas such as the Wee Bankie in the Firth of Forth, off the east coast of Scotland, that are also heavily exploited by seabirds gathering food for their young, despite warnings that this could have a significant effect. But the biggest identified effect of fishing on seabirds appears to be an unnatural increase. Fulmars and seagulls in particular exploit the huge amounts of offal, discards and by-catch dumped by the fishing vessels, making available food that would otherwise be beyond their reach. Perhaps as many as 2.5 million birds take advantage of this temporary bonanza. Nevertheless bird protection organisations, such as BirdLife International, consider this an unnatural and undesirable distortion of the ecosystem. They, like others, consider that fisheries must become ecologically sustainable so that the future of all parts of the North Sea ecosystem becomes secure.

One of the most worrying effects of fishing is upon marine mammals such as the porpoise. For example a partial survey of Danish fishing vessels in the North Sea, Skagerrak and Kattegat in 1983 recorded an average of one porpoise killed every trip. This means that the Danish fishing fleet alone was killing some 3,000 porpoises a year. Research conducted in 1993 suggests that the situation may be even worse. Danish gill-netting (between five to ten thousand kilometers of nets are set each day to catch mainly turbot, sole, plaice and cod) was estimated to kill 7,000 porpoises every year. Death on this scale could be very significant - one unofficial estimate is that it could represent 5% of the North Sea population. If true, this would be at least as significant as the deaths of dolphins in the tuna fisheries of the 1980s.

DWINDLING FISH

Unsurprisingly, the most obvious impact of fishing is upon the fish.

Coastal waters were the first to be affected by changes in fishing methods. In April 1884 a single haul of one of the new trawls around the Isle of May, in the Firth of Forth, produced 598 fish - a catch impossible today - including haddock, cod, whiting, ling, skate, thornback ray, witch, plaice, lemon dab and flounder, as well as hundreds of Norway lobsters.

Soon such catches were only memories, and the trawlers had to go further offshore. Here too, the stocks were rapidly depleted. The strongest evidence of this comes from size of catches before and after the Second World War. For six years fishing was severely restricted. When the British fleet started operating at full scale in 1947, the catch, for the same effort, was more than double that for the 1930s. But it fell rapidly: within four years it was virtually back to the pre-War levels.

The next big development was the Danish or purse seine. This allowed a curtain of net to be drawn completely around an entire shoal of surface swimming fish such as herring, mackerel or sprat. Once encircled the net was both drawn in and pulled tight at the bottom, capturing most of the shoal. This new method proved very effective - too effective. For the first time in the North Sea, fish stocks actually collapsed under the pressure. In fact, in the 1960s and 1970s, two stocks collapsed; the indigenous North Sea mackerel, and the herring. Mackerel has never recovered. Fishing for herring was banned in 1977 and the stock did recover. But unfortunately the lesson was not learnt, and fishing pressure once more began to grow. Now once more the herring is in severe trouble.

In the 1960s, when herring were severely depleted, members of the cod family - cod, haddock, saithe and whiting - unexpectedly increased between two and fourfold. Many believe that this was because herring, which feed on the larvae of these fish, were too scarce to have as great an effect. If true this indicates the scale of the knock-on effects that our activities can have.

But since that brief interlude, the numbers of cod and its relatives have been declining. The situation is now grave. The stock of cod is barely one third of what scientists believe is the minimum safe size. They even warned that, ideally, all fishing for cod in the North Sea should be stopped. The problem is that cod swim in mixed shoals, with other members of the cod family. Stopping cod fishing may also require a significant reduction in the catches of haddock, whiting and saithe. However, the stocks of these species are not in much better shape. In 1995 North Sea environment ministers endorsed a report that stated that cod in the Kattegat, and cod, haddock and saithe in the North Sea were all below 'safe biological limits', and they also expressed concern about trends in whiting stocks.

"models routinely used by biologists ..... induce overfishing." D. Pauly (International Centre for Aquatic Resources Management, Philippines)

Until recently there seemed to be one stock, North Sea plaice, that was able to withstand the enormous fishing pressure it was under. But now this too has fallen below what is believed to be the minimum safe population size, and there is also concern about English Channel sole. In effect, since the start of the 1990s, virtually all of the major stocks fished for human consumption in the North Sea have become threatened.

Scientists warn that the cod stocks in the North Sea are in grave danger.

INDUSTRIAL FISHERIES

Last, but not least, there are the industrial fisheries. Fish were first deliberately targeted for the production of fish meal and oil, rather than for human consumption, in the 1950s. Since then the industrial fisheries have grown enormously. They were one factor in the collapse of mackerel and herring, since which time they have moved on to smaller species such as sandeel, sprat and Norway pout.

One problem with industrial fisheries is the sheer size of the catches. Typically, each year the industrial fisheries now take over a million tonnes of fish - more than half the weight of all fish landed from the North Sea. The second problem is the 'accidental' catch (by-catch) of immature fish that are already threatened - such as haddock, whiting and herring. Last, but not least, is the unknown scale of impact on the marine food chain as the species prosecuted by the industrial fisheries are important prey for many other fish, sea mammals and birds.

The large-scale sandeel fishery in the North Sea is unregulated with no catch limits and takes between 8 and 20 billion fish each year. Incredibly, a recent European Commission regulation stated that: 'In the case of certain stocks fished mainly for reduction to meal and oil, it does not appear necessary to make quota allocations' (EC Reg 3074/95).