The most productive fisheries are those on the continental shelf. Demersal (bottom-living) fish like cod, haddock and plaice feed on the benthic fauna of the continental shelf, while pelagic fish such as herring, anchoveta and sardines feed on plankton in the water above the shelf. Ironically the fact that the best fisheries are closest to land makes them most likely to be over-used.
The rate at which a fish population grows is determined by nature
and hence there is a maximum rate at which fish can be killed
while allowing the population to replenish itself (the 'maximum
sustainable yield'). In many cases, such as European Union and
North Atlantic waters, this limit has been surpassed with
devastating results.
Overfishing is certainly not a new problem. As early as 1890
plaice stocks in the North Sea were being depleted. There are
many reasons for overfishing. Firstly technology has improved
dramatically over the last century. Bottom trawls catch demersal
fish while huge drift nets, tens of kilometres long, catch
pelagic fish. Large factory ships can process the fish while
still at sea, removing the need to return to port to unload.
Sonar and satellite imaging allow fish to be located more easily.
New methods of technology are also very wasteful. A large
percentage of each catch is normally thrown away because it is
the wrong species or the wrong size.
Secondly the huge international demand for fish means there is
always a market for fish. In countries like Japan fish is the
major protein source in the diet. Large-scale marketing campaigns
in the USA have caused shrimp consumption to treble. Some marine
life is also used as animal feed, for example sand eels from
Scotland are ground up and used as protein supplement for pigs
and cows. Banning the use of fish as animal feed would lead to an
immediate decrease in demand.
After the Second World War there was a worldwide drive to expand
fishing production, and fleets expanded even more rapidly than
catches. For a long time they were encouraged by increasing
catches, but even after the catches started falling off, they
kept increasing. This was partly due to what is known as the
'tragedy of the commons'. This compares the exploitation of
resources to the use of common land in medieval England. In
theory all the peasants could graze their animals on the land
freely. In reality this led to massive over-grazing. No one was
willing to remove their animals since this would give other
farmers an advantage. Similarly few counties are willing to cut
back fish production alone.
The overcapacity of fishing fleets is also due to governmental
subsidies. The European Union spends a large amount of money on
what many would describe as a dying industry. Indeed there is a
valid argument that fishing in the EU should be left to die.
However the political fallout from this would be immense. Fishing
has a political say out of proportion to the number of people it
employs (less than 1% of the workforce).
So what measures can be taken to prevent overfishing? The
European Union devised the Common Fisheries Policy to reduce
overfishing. This had three main strands. Technical measures such
as minimum net sizes, closure areas, minimum landing sizes and
catch restrictions were meant to reduce catches. Structural
reform would reduce capacity of the fleet, while Total Allowable
Catches would set quotas for species, areas, and individual boats.
It is widely acknowledged that this so-called 'Blue Europe'
policy failed, due to both internal and external factors.
Externally, competition from non-EU countries (who were not party
to the CFP and hence could fish freely) forced prices down,
meaning a larger catch was needed to make the same amount of
money. Aquaculture (fish farming) has provided an alternative way
of fish production, but this has its own environmental problems (see
later).
Internal factors also have an effect. Structural reform did not
manage to significantly reduce overcapacity. Quotas were often
ignored due to a lack of faith in governments, unequal monitoring
and policing, fraud and misrepresentation of catch sizes.
Another method for controlling fish stocks was the New Law of the
Sea, finally agreed by the UNCLOSIII treaty from 1972-82 and
signed by 116 counties in 1982 in Montego Bay, Jamaica. However
the treaty was weakened by the fact that many major powers did
not sign the treaty initially including the USA, UK and Germany.
Germany finally signed in 1994, the UK in 1997 while the USA and
Canada have still not signed. The treaty established Exclusive
Economic Zones of 200 nautical miles around marine nations, where
countries had the right to exploit fisheries, but also the
responsibility to manage them and the environment.
Of course marine territorial claims are as fiercely disputed as
those on land and there have been many flashpoints over fishing
rights. In the 1970s the 'Cod War' led two NATO allies, Iceland
and the UK, to the brink of war, while there have been many
disputes about fishing rights in the Bay of Biscay between the
UK, Spain and Ireland.
It is difficult for individual countries to reduce overfishing on
their own. For example in 1977 the UK protected its herring
fisheries. However other countries simply fished the herrings
more. Since herrings are transient they move as they mature so
instead of being killed in the British spawning grounds they were
simply killed in Danish nursery grounds instead. Another problem
was the effect on the food chain. The increased number of
herrings ate large amounts of plankton with disastrous effects on
other species.
Perhaps a good example of how fisheries should be managed is
given by Sri Lanka. Some 100,000 Sri Lankans support their
families comfortably as fishermen and so far there has been
plenty of fish for all. In 1997 the total catch was around 217,000
metric tons. Ministries report that tuna stocks, which comprise
half the total catch, are actually increasing at present. Data
logging is very much part of the fisherman's job; they have a
duty to record the dimensions, locations, and catch methods of
all the fish they catch. This is assisted by 173 fishing
inspectors making spot checks. So far the system seems to work
well, the main problem being poaching by other countries in Sri
Lanka's EEZ.
Aquaculture (fish farming) has experienced an explosion in scale
in recent years. Shrimp farming in particular is becoming
increasingly popular. One fear frequently voiced by
environmentalists is that the people constructing shallow ponds
for shrimp farming often destroy environmentally vulnerable
mangrove forests, which line tropical coasts. Mangrove forests
help filter excessive nutrients washed off the land and provide
shelter for young fish. However it has been argued that most
environmental damage occurs from poorly planned farms and lax
government agencies. Properly planned farms, which are expensive
to build, provide large numbers of jobs and are major import
earnings for developing nations without adversely damaging the
environment.
Recent developments suggest shrimp farmers are indeed moving
towards more environmentally friendly means of production, The
Australian Prawn farmers Association established a formal code of
practice and the ASEAN fisheries network in South-East Asia
published a manual of good practice. Most countries now require
an environmental assessment for new shrimp farms.
As we enter the 21st century things are looking increasingly
bleak for the global fishing industry. Increasingly desperate
measures are being taken in the EU to reduce overfishing, for
example a 12-week outright ban on cod fishing in the North Sea.
The EU has finally acknowledged the failure of the CFP, which is
to be reformed in 2002. However it may be too little, too late.
Some species have been hunted to commercial extinction, and
biological extinction may not be far off.
What is needed is a more coherent and co-operative global fishing
policy but as the UNCLOS treaty shows this can be very difficult
to achieve. It is very easy to say in hindsight that fishing has
been continuing at an unsustainable rate. The problem with the
fishing industry is that the individual governments and fishermen
have behaved perfectly rationally but the outcome has been to the
detriment of all of them.
Governments must be cruel to be kind and cut subsidies to the
fishing industry, but education programmes should be set in place
to provide new jobs for those put out of work. Quotas should
follow scientific advice and be reduced. The example of herring
in British waters in the 1970s shows efforts must be co-operative
between countries and species. If countries can be persuaded that
the way forward is sustainability there is still a glimmer of
hope.
Matthew Mayer