For most people, North Sea fishing is linked to images of fishermen fighting the elements to catch cod, herring or plaice. But during the last 40 years a huge "industrial" fishery has grown up largely unnoticed by the public, despite its massive size. It catches fish not for the table, but to be ground up into industrial products such as fish meal and oil.

Many consumers will be surprised to know that they are eating industrial fishery products either indirectly (used as food for livestock, poultry and farmed fish) or directly but anonymously, as "animal fat" in cakes, biscuits and margarine.

Astonishingly, this industrial fishery lands over a million tonnes of fish each year, more than half of all fish landed from the North Sea. These ~industrial~ fish are the food that many other marine species depend upon. The rapid and poorly regulated growth of this industry, and its potential for major ecological damage, gives cause for alarm.


Industrial fisheries developed from the processing of waste from normal fisheries into fertiliser and other products. With the 1950s came the increasing realisation that it was profitable to catch fish specifically for industrial products. This, coupled with over-fishing of fish for human consumption, and new technology such as sonar and the Danish or purse seine net, led to the rapid development of industrial fishing during the 1960s.

Major problems soon followed. Mackerel and herring, already under pressure from normal fishing, were initially targeted by the industrial fisheries because of their large size and high fat content. Pressure increased drastically during the late 1960s and there were warnings that the stocks could not withstand such an onslaught. However the industry argued that there was no proof. The inevitable happened. First the North Sea mackerel stock collapsed in 1970 and, despite a great reduction in fishing since 1970, the stock has never recovered. Then in the mid 1970s the herring stock collapsed. The fishery was forced to turn to smaller species, particularly Norway pout and sprat, until these catches also declined; some believe that the decline in sprat was also associated with over-fishing.

From 1985 to the 1990s sandeels constituted approximately two- thirds of the catch. The average total industrial catch between 1987-91 was some 1.3 million tonnes a year. This included an 'accidental' catch (by-catch) of 170 thousand tonnes of fish such as herring, whiting, haddock and saithe that otherwise would have grown and been available (and far more valuable) as fish for the table. Unfortunately, very little effort has been put into monitoring the North Sea industrial fisheries. What effort is made is often erroneous; catches are misidentified, the area in which they were caught is falsified, by-catch is underestimated. Monitoring of the health of stocks remaining in the sea is, if anything, even worse.

Sandeels illustrate some of the problems. The total landings of sandeels have grown since the 1960s until levelling off, since the mid-1980s, at around 700,000 tonnes or more. Attempts to estimate this as a proportion of the total stock vary from under one-quarter to almost half of the entire population caught each year. Moreover, this 'population' is not of one species, but five; but it is considered uneconomic to monitor them separately. It was also assumed until very recently that sandeel populations were composed of a couple of large homogenous North Sea stocks. It now appears that this includes many, relatively local and sedentary stocks and that the overall catch figures could conceal major depletions. For example, in 1993 the total catch from the important area in the north-west North Sea (Area 1A) was some 187,000 tonnes. But 115,000 tonnes came from just one small site - the Wee Bankie area, off the Scottish Firth of Forth. Often, after a few years of intensive fishing in an area, the catches fall and the boats move elsewhere - a pattern worryingly consistent with massive overfishing.


There is much evidence that industrial fishing has caused the collapse of fish stocks. Outside the North Sea most experts agree that industrial fishing contributed to the collapse of the Californian sardines in the middle of this century, the Peruvian anchovy in the 1970s and more recently the disastrous situation in the Japanese pilchard fishery. Closer to home, in the 1980s capelin stocks collapsed in the Barents Sea as did herring stocks in the Norwegian Sea, both after being subjected to intense fishing pressure. The links between industrial fishing and the depletion of mackerel and herring in the North Sea have already been described.

Such evidence counters the claim still sometimes made that, because each female fish may lay vast numbers of eggs each year, it is virtually impossible for fishing to cause any harm. By the time the fish are large enough to catch only a handful of these offspring will have survived and additional pressure on these few survivors from fishing may indeed have a serious effect.

Industrial fishing may also have an effect on other species of fish. There are two possible ways in which this may happen. First, other fish may be caught accidentally by the industrial fishery - the 'by-catch' problem. Second, species targeted by industrial fisheries may be important food for other fish. The catch of herring by the industrial fishery for sprat is an example of the by-catch problem. In theory, following the collapse of herring in the 1970s, industrial fishing for herring is no longer allowed. But young herring and sprats swim together in shoals, and industrial fishing for sprat is permitted. Fishers are allowed to catch a maximum of 10% of herring mixed in with the sprats. But in practice this limit is ignored and vast amounts of herring are still caught. Indeed, in 1991 more herring than sprats were landed by this 'sprat' fishery. This pressure, combined with fishing for human consumption, has once more brought herring to the brink of disaster. There is also a by-catch problem with Norway pout. Here it is mainly young whiting and haddock that are caught.

In 1992 a study carried out by the EU fisheries Commission, DGXIV, concluded that a 40% reduction of the North Sea, Skagerrak and Kattegat demersal industrial fisheries (essentially for Norway pout) would result in significant increases in whiting and haddock landings - at a net economic benefit.

For sandeels it is the reduction in food available to other fish that has attracted the greatest attention. It is sometimes asserted that whiting is the only serious predator of sandeels. But other research indicates that whiting, saithe and haddock can all be important, each taking between 75,000 and 250,000 tonnes of sandeels each year. And while some state that relatively few sandeels are taken by cod, it is clear that in some areas, such as Horns Reef (off the Danish coast), cod are 'full of sandeel' at certain times of the year. In any case cod are now so scarce, particularly in the southern North Sea, it is inevitable they will take only a small proportion of the sandeels. But their requirements may change if the stocks are allowed to recover.

Under natural circumstances, fish are by far the most important predators of sandeels. But the industrial fishery can be a severe competitor. Indeed, in some years it takes significantly more sandeels than any fish species. To allow industrial fisheries to continue unregulated and on this scale, while asserting that it can have no possible effect, is totally indefensible.


Because of their small size, many fish exploited by the industrial fishery are also vital to birds. Sandeels have been recorded in the diets of all species commonly occurring in the North Sea. More sandeels are eaten by birds than all other fish added together. During the breeding period over 90% of guillemots examined in the north-western North Sea had fed on sandeels, and they are known to be similarly important for other seabirds including great skua, puffin and fulmar.

With the exception of the birds around Shetland, oil-rich sprats are also significant, and are extensively taken as food for puffin chicks at sites such as the Isle of May in the Firth of Forth. Norway pout are also eaten where available by all birds with the exception of shearwaters and petrels. Moreover, in the breeding season, when birds are tied to their colonies, and need to find food for their chicks as well as themselves, the birds can require a significant proportion of local fish. Few detailed studies have been made, but around the Shetland Isles between 1981 and 1983 birds are thought to have consumed one-quarter of the local sandeel stock - a similar amount to the local fishery.

At the very least such figures suggest that competition between seabirds and the fisheries is possible. The major potential area of conflict is off the coast of Scotland and northern England. This area is of importance to both birds and the industrial fishery. A Danish report produced in the early 1990s warned that: 'changes in the distribution of fishing activities resulting in the exploitation of sandeel concentrations close to seabird colonies could have a serious effect on prey availability to seabirds'. Since that time, and despite that warning, the industrial fisheries have moved in to areas such as the Wee Bankie, which are of prime importance to the seabirds.

There are two ways in which an effect on the birds may be manifested. The first, and most likely, is changes in bird populations that occur slowly, over many years. The second effect is a catastrophic breeding failure. Fishing was suspected when Shetland seabirds repeatedly failed to breed in the 1980s, due to the scarcity of sandeels. In the event, changes in sea currents are the prime suspect, although precautionary restrictions on the fishery that were imposed at the time remain in force.

Catastrophic effects associated with fishing have occurred in the seas off north-west Europe; the breeding population of guillemots in northern Norway and Bear Island, south of Spitzbergen, collapsed from a population numbered in hundreds of thousands to just one-tenth of this in the late 1980s, following the crash of the capelin fishery. Similarly the Norwegian puffin colony at R st Island, numbering over a million pairs in 1977, had more than halved by 1988, coincident with the fishery-induced collapse of local herring. Despite this record, and concerns regarding the impact on birds in the North Sea, the industry has so far refused to take precautionary measures elsewhere.


There are approximately 70,000 seals in the North Sea whose total annual food consumption is in the order of 100,000 tonnes. Seal diet is very varied, and it is difficult to be certain of their food whilst foraging away from haul-outs. However the analysis of faeces left at haul-outs indicates that sandeels can make up over half of their diet. Grey seals also eat Norway pout. While common seals may stay in coastal waters and eat coastal fish, grey seals range much further. The general implication is that seals have little overall impact on the fish, but that the collapse of stocks targeted by industrial fisheries, particularly sandeels, would have serious implications for seals.

Very little is known about the possible impact on cetaceans. Of the baleen whales that enter the North Sea, both the fin whale and minke are known to feed on herring, sandeel and cod- fish - indeed one old English name for the fin whale was herring hog. Bottle-nosed dolphin, Orca and porpoise all include mackerel and herring in their diet. Some experts believe that over-fishing is one reason for the decline of the porpoise. As with birds, a collapse caused by industrial fisheries could do significant harm to marine mammals.


Given the ecological importance of fish targeted by industrial fisheries, near the bottom of the marine food web, one would expect that the industrial fisheries would be especially carefully regulated. But, astonishingly, the opposite is true. Until now this industry has had the most lax set of controls of any fishery in the North Sea.

With the exception of the small Shetland sandeel fishery, no controls are imposed to prevent possible over-exploitation of the stocks. Instead there has been a half-hearted attempt to reduce the by-catch of human consumption species that has conspicuously failed, for example with herring. Most incredible of all, the industrial fishery for North Sea sandeels has no limit of any kind. There are of course other major fishing problems in the North Sea such as the crisis facing stocks for human consumption, and the environmental impact of fishing activities. Change is never easy, and compensation of various forms may be necessary.

Other problems and difficulties are no excuse for the failure to take action on industrial fisheries. They are the clearest possible example of the need to apply precautionary measures. Denmark and Norway, the principal countries involved in these fisheries have, to their credit, long applied the precautionary principle elsewhere in environmental policy. They have often been in the vanguard, demanding precautionary action by others that was both difficult and controversial. Now Denmark and Norway face their moment of truth.


Greenpeace demands that the precautionary principle be applied to North Sea industrial fisheries and give the marine environment the benefit of the doubt. Regulations should be set which reflect the uncertainties of the impact of industrial fisheries. In addition, there must be a complete ban in specific sensitive areas where the fishery is in conflict with the needs of other marine species, such as sea birds and mammals as well as other fish stocks, such as haddock, cod, herring and whiting.

  • Industrial fisheries catch fish not for human consumption but for making industrial fish meal and oil.
  • Industrial fisheries account for over 1 million tonnes of fish, more than half of all fish landed from the North Sea.
  • Industrial fisheries contributed to the collapse of North Sea mackerel and herring stocks in the late 60s and early 70s.
  • Industrial fisheries are now targeted at sandeels, Norway pout and sprat, but accidentally catch at least 170,000 tonnes of species such as haddock, whiting, and saithe.
  • Industrial fisheries also remove important food supplies for other fish, marine mammals and birds and may threaten their populations.
  • Industrial fisheries are poorly regulated, with virtually no controls to prevent over-exploitation of the stocks.

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