Turning Back the Clock 200 Years Why we must
put refuges back in the oceans
Callum M. Roberts
In days when sailing ships plied the oceans, and fishers
hauled their nets by hand, the sea was full of fish.
So plentiful was the supply that renowned Victorian
scientist Thomas Huxley declared, at London’s
International Fisheries Exhibition in 1883, the great
fisheries of the world to be inexhaustible. His view
of the state of the oceans prevailed throughout the
first half of the 20th Century. Optimism ran high that
fish could feed the world, so much so that Rachel Carson
and others wrote books urging people to eat more fish
and to use the resources of the sea more fully.
Today that optimism has all but evaporated and the world’s
fish supplies are running dangerously low. New research
suggests that stocks of many of the world’s great
fisheries have declined to 10% or less of their unexploited
levels. Trawlers now trawl half of the world’s
continental shelves every year. In many places the seabed
has been ploughed bare, destroying rich communities
of corals, seafans and sponges, and levelling the habitats
of fish. As shallow water stocks are depleted, the global
fishing fleet is penetrating deeper, seeking fish in
the realm of permanent night – the last place
on Earth that has never experienced ‘Man the hunter’.
The species that live in the deep sea are ill equipped
for such an onslaught and, place-by-place, are silently
disappearing within a decade or two of the first hooks
and nets appearing.
We also worry about growing pollution in our estuaries
and coasts. Anoxic ‘dead zones’ are spreading
around the mouths of rivers like the Mississippi and
the Severn, and toxic plankton blooms blight our visits
to the beach. The blue, pellucid waters are turning
green. Scientists link such problems to depletion of
fish and shellfish as well as increased levels of fertilising
pollutants. Fishing has removed the consumers that filter
the water and eat the microbial slime. In combination,
overfishing and pollution are transforming the sea.
What has changed since the days of plenty? We have vastly
expanded the scale and intensity of fishing. Our modern
high technology fishing armoury allows us to fish harder,
more efficiently, deeper, longer, and farther afield
than in the past. Today there is almost nowhere less
than 1,500 metres deep that is not exploited.
A century ago, we tapped only a fraction of the wealth
of oceans. Trawlers avoided areas of rugged seabed for
fear of damage or loss to their nets. Places where navigation
was hazardous, areas with strong tidal streams and wave
tossed coasts were shunned as too dangerous. The reach
of fishing gears was limited, and in any case, there
was no point in fishing deep water when there was plenty
to catch in the shallows.
Today, we are coming to realise that such ‘natural
refuges’ from fishing once played a critical role
in sustaining fisheries and maintaining healthy and
diverse marine ecosystems. Paradoxically, unexploited
areas can boost catches from surrounding fishing grounds.
Fish and shellfish in refuges live longer, grow larger
and are more numerous than those that are fished. Big
fish produce many times more offspring than small. Their
eggs are also larger and carry more food reserves, giving
larvae a better start in life. Most of the animals we
exploit begin life as eggs and larvae - this open water
dispersal phase carries animals spawned in refuges into
fishing grounds where they can replenish fisheries.
The high population densities reached in unexploited
areas can supply fishing grounds in a second way, called
‘spillover’. Animals may leave refuges in
search of less crowded places, that is, fishing grounds,
where competition for space and food may be less, and
where they can also be caught.
With the expansion of fishing, the natural refuges are
all but gone, and there are almost no statutory protected
areas to replace them. Twelve percent of the world’s
land now lies in protected areas, while the corresponding
figure for the sea is less than one percent. Worse still,
most marine protected areas allow fishing. Fully protected
marine reserves – areas off limits to all exploitation
– cover as little as one five thousandth of the
total area of the world’s seas.
Rachel Carson predicted a silent spring if we could
not curb our use of pesticides, but she never dreamt
of an empty ocean. Yet this is where we are currently
heading. Almost everywhere, both large and small animals
are disappearing from the sea, although since few have
yet gone forever, we still have time to change course.
To avert an extinction wave engulfing the sea we need
to massively expand the world’s networks of marine
protected areas. At the 2002 World Summit on Sustainable
Development, coastal nations of the world, including
Britain, committed to create national networks of marine
protected areas by 2012. But to properly protect marine
habitats and fish stocks, marine protected areas must
provide real protection from fishing. As yet we have
no legal mechanism to do this in Britain, other than
by using fisheries legislation. But fishery managers
have proven reluctant to use their powers for the benefit
of conservation. A proposal for a no-take zone in one
of Britain’s only three Marine Nature Reserves
was this year thrown out by the South Wales Sea Fisheries
Committee, for example. It is vital that the new Marine
Bill addresses this gaping hole in Britain’s conservation
toolkit.
In places where people have taken the plunge and set
up fully protected marine reserves and looked after
them well, the results have been spectacular. The amounts
of commercially important animals in reserves can double
or even quadruple within a few years of protection.
For example, around the coast of St. Lucia in the West
Indies, local people agreed in 1995 to establish a network
of four marine reserves interspersed with areas that
remain open to fishing. The reserves cover 35% of the
coral reef fishing grounds and are patrolled daily by
park wardens. By 2002, fish stocks in the reserves had
increased by nearly five times, while those in fishing
grounds had grown two and a half times. Moreover, fish
catches nearly doubled, despite the reduced area of
fishing grounds. The initially sceptical fishers in
St. Lucia have now become vocal supporters of protection.
Similar experiences are being reported from many other
parts of the world. In Apo Island in the Philippines,
large and valuable fish are more common in the vicinity
of the island’s marine reserve and villagers catch
ten times as many fish per hour as they did twenty years
ago. In Georges Bank in the Gulf of Maine, fishers have
seen the struggling scallop fishery make a spectacular
recovery after a series of large protected areas covering
40% of the scallop fishing grounds was created. Although
only trawlers and dredges are excluded from the George’s
Bank protected areas, in combination with a reduction
in fishing effort in the surrounding fisheries, they
have helped reverse a long-term trend of decline in
fish stocks and landings.
To recover the world’s fisheries we must change
the way we think about and manage the oceans. For much
of the last hundred years, fishery management has been
conducted as an arms race between fishers and regulators.
Regulators make laws to restrain fishing, fishers think
up ways around them. In most places, fishers have kept
one step ahead of regulators and stocks have fallen.
The command and control model of fishery management
is failing. Ultimately, if fishers win the race with
regulators it will lead the fishing industry to self-destruct.
Fisheries will become sustainable only when we set more
modest catch targets and fish in ways that have less
impact on fish habitats and other marine species. Creating
protected areas can help places recover from the impacts
of fishing, so rebuilding the resilience of ocean ecosystems
and recovering the diminished productivity of fish stocks.
The best available science indicates that we can maximise
fishery benefits by placing around one third of the
sea off limits to all fishing. Such a large-scale network
of marine reserves, if established in the right places,
could also afford protection to the full spectrum of
marine life. Of course marine reserves have limitations.
They must be combined with the best of our existing
fishery management tools to prevent overfishing, safeguard
the most mobile species and avert degradation of habitats
in areas that continue being fished. They will be vulnerable
to pollution washing into them from sources outside
their boundaries. Tackling pollution requires policies
and laws that target sources that may be thousands of
miles from the coast. Marine reserves are not the sole
solution to problems in the sea, but we cannot solve
our problems without them.
Site map