This will affect fish stocks and, as a result, threaten the livelihoods of small-scale fishing communities.
"Acidity levels of our oceans predominantly affect fish larvae, which
depend on calcium carbonate in the seawater to build their shells,
skeletons and cell coverings," explained professor Geoff Brundritt,
chairperson of the Global Ocean Observing System in Africa (GOOS
Africa). "A higher acidity level hampers this process."
"Fish larvae thus have a slimmer chance of reaching adulthood, which
hampers the fish from reproducing and keeping the stocks in shape," he
added. "This not only threatens the future of fish stocks, it also
poses a threat to communities that depend on fishing for their
survival."
Fishing communities in the developing world, including southern Africa,
are already among the most vulnerable population groups in the world.
According to the United Nations Food and Agricultural Organisation
(FAO), their living conditions are characterised by overcrowding, low
levels of education as well as lack of access to schools, health care
facilities and infrastructure, such as roads or markets to sell their
ware.
Operating like enormous "vacuum cleaners", oceans naturally absorb CO2
from the atmosphere, said Brundritt. But because levels of this acidic
gas in the air have increased due to climate change, oceans have been
sucking up more CO2 than previously, which has contributed to oceanic
acidification.
The United Nations Intergovernmental Panel on Climate Change (IPCC)
reported in 2007 that the oceans’ pH – currently between 7.9 and 8.2 –
will fall by a further 0.14 to 0.35 units before the turn of the
century. The lower the pH, the more acidic the water; the ideal pH
level in saltwater systems should lie between 7.6 and 8.4.
Rising temperatures
To make matters worse, rising temperatures of sea surface waters also negatively affect fish stocks.
"Higher sea surface temperatures do not kill fish as such, but they do
seem to chase them away from their grounds, which has an impact on the
communities who rely on these stocks," said Larry Hutchings, marine and
coastal management researcher for the City of Cape Town in South
Africa.
As a result, small-scale fishermen will have to go further and further
out to sea to cast their nets, but most of them cannot afford to invest
in the necessary boats and technology to do so.
Already in 2007, South African Department of Environmental Affairs and
Tourism deputy general, Monde Mayekiso, publicly warned about the
averse effects climate change is likely to have in fishermen’s
livelihoods.
"Scientists have not categorically stated that migration of sardines,
for example, is caused by climate change but we do note that the
reduction of fish along the West Coast has been associated with
extraordinarily warmer water," he told The Citizen newspaper. "This
suggests that it could be [related to] climate change."
Mafaniso Hara, senior researcher at the South African Institute for
Poverty, Land and Agrarian Studies (PLAAS) agrees: "We suspect that the
migration of sardines to the South Coast, in the area of Mossel Bay,
indeed has to do with rising sea surface temperatures. The catches have
declined from 300,000 tons a few years ago to 100,000 tons per year."
As a result, fishing communities along South Africa’s West Coast are
feeling the pinch, even though schools of another fish species, horse
mackerel, have moved closer to shore. But these fish are less valuable
on the market and harder to catch than sardines.
"Horse mackerels live at greater depths, where the water is cooler,"
Hutchings said. "As a result, these fish can only be caught with big
trawlers and are therefore out of reach of small-scale fishermen."
The migration of the sardines has already had a negative impact on
employment along the West Coast, Hara said: "There is not enough fish
for processing, so jobs have been cut and people retrenched. This has a
big impact on communities along the West Coast, which already struggle
with poverty."
Job cuts
According to PLAAS, many fishing communities along the West Coast fully
depend on the fishing industry and government grants, like child
support grants, for their survival. With the fishing industry
declining, communities will rely more and more on being supported by
the grant system.
"In Hondeklipbaai, a small fishing community on the West Coast, for
instance, people are fully dependent on government grants for their
survival, as the fishing industry there has almost vanished," said
PLAAS researcher Moeniba Issacs. "If these grants would be pulled out
for one reason or another, this community would be doomed."
Fishing communities on the country’s West Coast are also taking strain
because rock lobsters, another major source of income, have started to
migrate southwards.
Figures by the South African department of Environmental Affairs and
Tourism (DEAT) show that 30 years ago, 70 percent of rock lobster was
caught along the West Coast. Today, 90 percent is caught about 300
kilometres further south, close to Cape Point.
But, Hutchings said, both the sardine and rock lobster migration are a
two-edged sword: "While fishermen along the West Coast are struggling
as a result of migrating fish and rock lobster, communities along the
South Coast and around Mossel Bay have gained employment and are better
off."
Theoretically, one could suggest that fishing communities along the
West Coast should move with the fish, but this is easier said than
done, explains Hutchings, as the distance between for instance
Hondeklipbaai and Mossel Bay is approximately 800 kilometres.
"As I pointed out, most West Coast fishermen are very poor," agreed
Isaacs. "They can’t pack their bags and leave, because they don’t have
the financial means to do so."
Sustained livelihoods for more than 30,000 who live in fishing
communities along South Africa’s coast are also limited by quotas,
which allocate the majority of allowable catches to the commercial
fishing industry.
(IPS)
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