new report by Oceana, an international ocean conservation organization.Pakistan, Thailand, the Philippines, Iran, and China are among the top 50 nations whose food security may be threatened by the effects that the rise of manmade carbon-dioxide (CO2) gas emissions are already starting to have on fish and shellfish, according to a
Coral reef ecosystems are especially susceptible to
damage from the increasing acidity of ocean waters. Click on the image
to see a larger version.
Credit: NOAA Photo Library.
While global warming is expected to affect the food supply of many
nations by increasing drought, heat waves and torrential downpours, this
report focuses on countries that depend heavily on the oceans for
“Fish and seafood are an important source of protein for a billion of
the poorest people on Earth,” said Matthew Huelsenbeck, a marine
scientist with Oceana, “and about three billion people get 15 percent or
more of their annual protein from the sea.”
In order to assess which countries are at greatest risk, Huelsenbeck
and his colleagues looked at two entirely different effects of CO2 on
the oceans: the warming caused when carbon dioxide traps extra heat from the Sun, and the rise in the acidity of seawater as it absorbs some human CO2 emissions to form carbonic acid.
Increased acidity makes it harder for shell-forming organisms, such as
clams, oysters, and corals, to build their shells. That in turn affects
people who depend on these sea creatures for food, or who eat the fish
that depend on coral reefs for their habitat.
Rising temperatures, meanwhile, have forced some fish to migrate away
from their normal territory. “Some fish just don’t like it too hot,”
Huelsenbeck said. A recent NOAA study,
for example, found that Atlantic cod populations in the Gulf of Maine
are shifting northeastward in response to rising ocean temperatures. In
fact, the waters off the coast of New England were the warmest on record
this year. Fish migration may not be a big problem for countries with
modern fishing fleets, such as the U.S., but poorer nations with more
local fishing fleets can’t simply follow their food supplies as they
The disparity in resources between rich and poor countries, combined
with projections of population growth through 2050 and the percentage of
the population that’s undernourished, were the main factors that went
into the national rankings, under the heading: “Lack of Adaptive
Capacity.” Another main factor was “Exposure,” meaning the vulnerability
of nearby seafood supplies to both warming and acidification. The final
factor in the rankings was “Dependence” — the degree to which each
country relies on protein from the sea in its mix of food sources.
CO2 from the atmosphere gets absorbed by the oceans,
and chemical reactions take place that break it down into carbonic acid,
which harms marine life. Click on the image for a larger version.
Put all of these factors together, and the most endangered country in terms of marine food security turns out be the Maldives,
the low-lying island nation in the Indian Ocean that’s already under
imminent threat from rising seas. Pakistan, at number eight on the list,
is the worst-off of major countries, followed at number 10 by Thailand.
Iran occupies the 27th spot, the Phillipines are ranked 34th, followed
by China at number 35. Peru and South Africa also are ranked among the
top 50 countries lacking adaptive capacity.
While it’s possible to deal with some aspects of climate change through
adaptation — building sea walls to keep out the rising ocean, for
example, or irrigating crops affected by drought — there’s really no way
to de-acidify the ocean once it’s undergone that chemical change.
Even the wildly ambitious geoengineering schemes
that propose to cool off the planet by reflecting extra sunlight back
into space would do nothing to keep seawater from growing progressively
more acidic. “Reducing emissions,” Huelsenbeck said, “is the only way to
The report urges governments to “establish energy plans that chart a
course for shifting away from fossil fuels and toward clean energy
production” and to end fossil-fuel subsidies — but environmentalists
have been saying pretty much the same thing for years, with little
The authors also urge a reduction in overfishing and other destructive
fishing practices. They call for the establishment of marine protected
areas where fishing is banned entirely and pollution is cut back
dramatically, to give marine populations at least a fighting chance of
staying somewhat healthy. And they urge fisheries managers to take
climate change and ocean acidification into account when putting
together fishing regulations and policies.
These suggestions are ambitious as well, but they may be a more
realistic bet — for the moment, at least — for keeping the nations at
greatest risk from losing some of their crucial supply of nourishment
from the sea.