The fishing industry is responsible for some of the most
environmentally damaging practices affecting our seas and oceans today.
Bottom-trawling (trawling for fish on the ocean floor) destroys the fragile
ecosystem of the sea-bed, and while debates about quotas are reported
in the news, illegal fishing remains widespread.
The very existence of many species is threatened by society’s appetite
for fish flesh as over fishing has resulted in tuna, cod, swordfish and
marlin populations declining by 90% during the last century(22).
Blue-fin tuna, for example, is one of the most valuable fish on the planet.
There
is an increasing demand for its capture with almost one third of catches
from the Mediterranean alone arising from illegal and unregulated fishing(23).
In a report released in October 2006 by the International Council for the
Exploration of the Sea (ICES), they state that the overall state of fish
stocks has not improved much from 2005 to 2006(24). ICES is an organisation
that coordinates and promotes more research in the North Atlantic. The
report advises that numerous stocks are too heavily fished and that some
stocks are depleted, e.g. cod and sand eel in the North Sea. ICES advises
that there should be no catch in 2007 for all southern cod stocks, whilst
sand eel fisheries remain closed until there is information available that
indicates a rebuilding of stock. Sand eel is an important forage species
for some seabirds.
Japan has recently made a rare admission that its fishing vessels have
exceeded quotas, and so the country has agreed to halve its catch of southern
blue-fin tuna for the next five years. However, the environmental group
the World Wide Fund for Nature (WWF) is concerned that this will still
not give the fish chance to recover fully(25).
Fish farming is responsible for pollution and endangering wildlife. Farmed
fish have to eat, and the feeding of carnivorous fish intensifies the pressure
on the oceanic fisheries. For example, it takes 5 tonnes of wild caught
fish to feed each tonne of farmed salmon(26). Other concerns include
the prospect of farmed salmon escaping into the wild and breeding, thus
weakening
the wild salmon’s capacity to survive. There is also the issue of
the large quantities of waste that fish-farming creates. In Scotland alone,
for example, it has been reported that over the past 3 years salmon farmers
have breached pollution limits more than 400 times(27).
Researchers are constantly trying to develop genetic engineering techniques
in the hope of producing fish with greater economical value. The addition
of an extra set of chromosomes (triploidy) is often used to produce sterile,
all-female fish which will not interbreed with wild populations if they
escape. This genetic modification affects both the health and welfare of
the fish with higher levels of spinal deformities being found in triploid
rainbow trout(7). Scientific advisors to the UK government say
that the implications of genetic modification in fish farming are “too
risky” in
that fish should not be farmed in pens set in rivers or the sea. There
is the possibility that fish might escape into the environment with unforeseeable
consequences(28).
Destructive fishing practices have spread in some poor coastal communities,
for example, the use of dynamite and poison. In the Philippines, explosives
are used on coral reefs to capture fish. The shock waves can kill fish
in a radius of 50m from the site of blast. The use of dredges also causes
changes in the bottom structure and microhabitats. Dredging is used for
harvesting oysters, clams and scallops from the seabed(29).
(italicised numbers in brackets indicate references) |
