Global fish stocks are exploited or depleted to such an extent that
without urgent measures we may be the last generation to catch food from
the oceans.
It has been some time since most humans lived as hunter-gatherers –
with one important exception. Fish are the last wild animal that we hunt
in large numbers. And yet, we may be the last generation to do so.
Entire species of marine life will never be seen in the Anthropocene (the Age of Man), let alone tasted, if we do not curb our insatiable voracity for fish. Last year, global fish consumption hit a record high
of 17 kg (37 pounds) per person per year, even though global fish
stocks have continued to decline. On average, people eat four times as
much fish now than they did in 1950.
Around 85% of global fish
stocks are over-exploited, depleted, fully exploited or in recovery from
exploitation. Only this week, a report suggested
there may be fewer than 100 cod over the age of 13 years in the North
Sea between the United Kingdom and Scandinavia. It’s a worrying sign
that we are losing fish old enough to create offspring that replenish
populations.
Large areas of seabed in the Mediterranean and North
Sea now resemble a desert – the seas have been expunged of fish using
increasingly efficient methods such as bottom trawling. And now, these
heavily subsidised industrial fleets are cleaning up tropical oceans
too. One-quarter of the EU catch is now made outside European waters,
much of it in previously rich West African seas, where each trawler can
scoop up hundreds of thousands of kilos of fish in a day. All West
African fisheries are now over-exploited, coastal fisheries have
declined 50% in the past 30 years, according to the UN Food and Agriculture Organisation.
Catches in the tropics are expected to decline a further 40% by 2050, and yet some 400 million people
in Africa and Southeast Asia rely on fish caught (mainly through
artisanal fishing) to provide their protein and minerals. With climate
change expected to impact agricultural production, people are going to
rely more than ever on fish for their nutritional needs.
The policy of subsidising vast fishing fleets to catch ever-diminishing stocks is unsustainable. In Spain, for example, one in three fish
landed is paid for by subsidy. Governments, concerned with keeping jobs
alive in the fishing industry in the short-term, are essentially paying
people to extinguish their own long-term job prospects – not to mention
the effect on the next generation of fishermen. Artisanal fishing
catches half the world’s fish, yet it provides 90% of the sector’s jobs.
Protect depletion
Clearly,
industrialised countries are not about to return to traditional
methods. However, the disastrous management of the industry needs to be
reformed if we are to restore fisheries to a sustainable level. In the
EU alone, restoring stocks would result in greater catches of an
estimated 3.5 tonnes, worth £2.7 billion a year.
Rather
than having a system in which the EU members each hustle for the
biggest quotas – which are already set far beyond what is sustainable –
fisheries experts suggest individual governments should set quotas based
on stock levels in their surrounding waters. Fishermen should be given
responsibility over the fish they hunt – they have a vested interest in
seeing stocks improve, after all – and this could be in the form of
individual tradable catch shares of the quotas. Such policies end the tragedy of the commons
situation whereby everyone grabs as much as they can from the oceans
before their rival nets the last fish, and it’s been used successfully
in countries from Iceland to New Zealand to the US. Research shows that managing fisheries in this way means they are twice as likely to avoid collapse as open-access fisheries.
In
severely depleted zones, the only way to restore stocks is by
introducing protected reserves where all fishing is banned. In other
areas, quota compliance needs to be properly monitored – fishing vessels
could be licensed and fitted with tracking devices to ensure they don’t
stray into illegal areas, spot-checks on fish could be carried out to
ensure size and species, and fish could even be tagged, so that the
authorities and consumers can ensure its sustainable source.
The other option is to take humanity's usual method of dealing with food shortages, and move from hunter-gathering to farming.
Already,
more than half of the fish we eat comes from farms – in China, it’s as
high as 80% – but doing this on an industrial scale has its problems.
Farms are stocked with wild fish, which must then be fed – larger fish
like salmon and tuna eat as much as 20 times their weight in smaller
fish like anchovies and herring. This has led to overfishing of these
smaller fish, but if farmed fish are fed a vegetarian diet, they lack
the prized omega-3 oils that make them nutritious, and they do not look
or taste like the wild varieties. Scientists are working to create an
artificial version of omega-3 – current synthetic omega-3 versions are
derived from fish oils.
Fish farms are also highly polluting. They
produce a slurry of toxic run-off – manure – which fertilises algae in
the oceans, reducing the oxygen available to other species and creates
dead zones. Scotland's salmon-farming industry, for example, produces
the same amount of nitrogen waste as the untreated sewage of 3.2 million people – over half the country's population. As a result, there are campaigns to ban aquaculture from coastal areas.
Farmed
fish are also breeding grounds for infection and parasites that kill
off large proportions of fish – escapees then frequently infect wild
populations. Farmers try to control infestations with antibiotics, but
usually only succeed in creating a bigger problem of antibiotic
resistance.
Dangerous predator
Humanity is
not limiting its impacts to fish most commonly found on menus. Exotic
sea creatures from turtles to manta ray to marine mammals are being
hunted to extinction. Shark numbers, for example, have declined by 80% worldwide, with one-third of shark species now at risk of extinction. The top marine predator is no longer the shark, it’s us.
A
decline in shark numbers has a significant impact on the marine
ecosystem: it can lead to an increase in fish numbers further down the
food chain, which in turn can cause a crash in the population of very
small marine life, such as plankton. Without the smallest creatures, the
entire system is threatened.
One of the repercussions, which I have discussed before, is an increase in jellyfish numbers, but overfishing, pollution, climate change and acidification
also affect the marine ecosystem. Warmer waters are pushing species
into different habitats, causing some to die off and others to adapt by
creating entirely new hybrid species. Meanwhile, trawlers are netting
bycatch that include marine mammals and even seabirds – as many as 320,000 seabirds are being killed annually when they get caught in fishing lines, pushing populations of albatrosses, petrels and shearwaters to the edge of extinction.
Some
solutions are easier than you might think. Seabirds can be protected by
using weighted lines and scaring off birds with lines that have
flapping streamers attached – these methods alone have reduced seabird deaths by more than 85-99% where they are used.
Conservation plea
Strengthening
and expanding protected marine reserves would also go a long way to
conserving species. Currently, less than 1% of the ocean is protected,
although by 2020, the international community has agreed
to raise this to 10%. Reserves, when properly patrolled and monitored,
do protect marine life, and nation after nation is stepping up to the
plate. The tiny Pacific islands have banded together to create a giant protected area of 1.1 million square kilometres, for example. Not to be outdone, Australia has created the world’s biggest protected area, and countries around the world from Britain to New Zealand are joining the effort.
But
useful as they are, marine reserves – often around points like coral
reefs or rock islands – are only effective if governments have the
resources to patrol and protect them. Also, many marine creatures, from
whale sharks to whales, are migratory – they don’t stay in the protected
areas, making them easy prey for fishermen. What’s needed, many argue,
are mobile reserves that follow migratory animals, and those that shift
habitat due to currents or climate phenomena like El Nino
The zones need to be well-targeted and needn’t impact on fishermen’s
livelihoods. For example, one study found that designating just 20 sites
– 4% of the world’s oceans – as conservation zones could protect 108 species (84%) of the world’s marine mammals.
The
rivers in many European cities were so overfished, polluted and dammed
up by the mid 20th century that they emptied of fish, and many species
went locally extinct. But thanks to clean-ups, riverbank restoration and
fishing restrictions, fish are returning to waterways, even in inner
cities. A decade ago, few people would have imagined that salmon would return
to my local river, the Thames. If it is possible to bring back fish to
'dead' rivers, there is surely hope for the world's oceans.
(source : www.bbc.com)
0 comments:
Post a Comment