As a general rule, the most successful man in life
is the man who has the best information
In A Harsh Reality I wrote about the Green Revolution and its effects on food production. In this article I’d like to focus your attention on our ocean
fisheries.
World fisheries are in a state of collapse –
caught between plagues of jellyfish, overfishing, nutrient pollution,
bioaccumulation of toxics in marine mammals, carbon emissions turning our
oceans acidic, the oceans phytoplankton declining by about 40 per cent over
the past century, dead zones, garbage patch’s, increasing ocean
temperatures and changing currents - our entire marine food chain seems to be
in peril.
Populations of jellyfish are exploding around the
globe. They feed on the same kinds of prey as fish so if fish numbers are
depleted jellyfish fill the gap.
Overfishing isn't the only explanation for exploding
jellyfish populations.
An ocean dead zone is an area of the ocean
that’s hypoxic, which means that it has low oxygen. The reasons for
ocean dead zones are most commonly attributed to toxic chemicals and human
waste (eutrophication - high levels of nutrients),
infiltrating the water near coastlines. The low oxygen levels created favor
jellyfish as they can thrive in oxygen depleted water whereas fish
can’t.
Oceanographers first began noticing ocean dead zones
in the 1970s, and instances of dead zones have been increasing ever since - a
tenfold global increase over the last 40 years. Large lakes can also have
dead zones.
Phytoplankton are microscopic single cell plant organisms and are the most abundant
vegetation in the ocean - they drift in the ocean currents and occupy most of
the surface area of the earth's oceans. They are the first, the bottom link, in the oceanic food chain - they are the crucial
nutrient at the base of the food chain on which all marine life depends.
They are eaten by zooplankton
(microscopic animal organisms) which are eaten by other animals, which
are then consumed by other animals higher up the food chain.
Temperatures on the surface of our oceans are rising
- the result is a reduction in the numbers of phytoplankton. Since 1950,
phytoplankton numbers have declined globally by about 40 percent. Experts are
already warning us that because of overfishing the world's fisheries could
collapse by 2050 - the decline in phytoplankton could make the situation even
worse.
Half of the oxygen produced by plants comes from
phytoplankton. They are vital in maintaining the earth’s atmosphere and
the oxygen we need to survive. For a long time there has been an extremely
small, but constant, decline in the oxygen content of our atmosphere. It's
possible that the loss of phytoplankton could be a factor. Phytoplankton
also absorb a huge amount of carbon dioxide each year.
Ocean acidification is the name given to the ongoing
decrease in the pH of the Earth's oceans. CO2 dissolving in seawater
increases the hydrogen ion concentration in the ocean, thus decreasing ocean pH. Between 1751 and 1994 the ocean surface pH is
estimated to have decreased from approximately 8.25 to 8.14 - an acidity
increase of roughly 30%.
“Ocean
acidification only really came to the fore about five years ago…As
acidity and sea temperature increase, the ocean’s ability to absorb
atmospheric CO2 will be reduced…this could trigger a chain reaction
that reverberates throughout the marine food web … starting with vulnerable
species such as larval fish and shell fish, and ending with detrimental
effects to the global fishing industry and the food security of many of the
world’s poorest people.” Professor Dan Laffoley, co-editor ‘Ocean Acidification: The
Facts’
About 6.4 million tons of marine litter are disposed
of in the oceans and seas each year - some eight million items of marine
litter are dumped in oceans and seas every day - up to 80 per cent of marine
garbage is thought to come from land-based sources. 2005 United Nations
Environmental Program Report
The Pacific, the Atlantic and Indian Ocean
“Garbage Patch’s” formed as a result of marine pollution
gathered by oceanic currents.
Tiny pieces of trash, each less than a tenth the
weight of a paper clip, make up most of the debris. In some places the
Atlantic Ocean Garbage Patch contained more
than 200,000 bits of trash per square kilometer.
The Great Pacific Garbage Patch was found to have as
many as 750,000 bits of plastic per square kilometer. If that’s not bad
enough waves often carry the plastic as much as 20 meters below the surface.
The powerful ocean current system creates a flow of
warm surface water, the Gulf Stream, from the Caribbean northwards. A branch
of the Gulf Stream, the North Atlantic Drift, transports warm water into the
north Atlantic. As it travels to the Arctic the warm water heats the
countries of the North Atlantic. As the water gets further and further north
it cools, which increases its density. The dense water sinks to the bottom of
the ocean where it is carried back to the equator. Think of it, as an on its
side, oval racetrack stretching from the Caribbean into the northern
Atlantic.
Research has found that the influence of the cold
water Labrador Current on the Gulf Stream has
been decreasing continually since the 1970s. In May 2005, researchers
reported the results of an investigation measuring the giant chimneys of cold
dense water by which the water normally sinks down to the sea bed. They found
the chimneys have virtually disappeared. Usually there are seven to twelve
giant columns, but they found only two giant columns, both extremely weak.
A Gulf Stream shutdown or a slowdown could have
major consequences regarding fish stocks:
- A collapse of plankton
stocks
- An oceanic
anoxic event - oxygen below surface levels of the stagnant oceans
becomes depleted
Consider all of the above, then
read the rest of the article. You can see where we might run into some
trouble regarding global fisheries.
The UN’s Food and Agriculture Organization
(FAO) says “The maximum
wild capture fishery potential from the world’s oceans has probably
been reached.”
FAO scientists publish a two yearly report (SOFIA)
on the state of the world's fisheries and aquaculture:
- 53% of
fish stocks are fully exploited
- 32% are
over exploited, depleted or recovering from depletion
SOFIA 2010 recorded a rise to 85% in the number of
fisheries that are fully exploited or over exploited, depleted or recovering
from depletion.
Most of the stocks of the top ten species (30
percent of the worlds marine fisheries production in
terms of quantity) are fully exploited. The proportion of under or moderately
exploited fisheries able to produce higher catches is 15 per cent - the
lowest level recorded since the mid 1970s
“In
a world likely to face a future of increasing food prices and decreasing food
security it is becoming more and more apparent that running down one fishery
after another is a disaster in the making.” Alfred Schumm, leader of WWF’s
global Smart Fishing Initiative
Industrial fishing has, over the past fifty years,
depleted the topmost links in the marine food chain - worldwide about 90% of
the stocks of large predatory fish stocks have disappeared. We’ve been
“fishing down the food chain” - as the larger fish disappear we
go after smaller and smaller fish.
Conclusion
Globally, fish provides more than 1.5 billion people
with almost 20 percent of their average per capita intake of animal protein,
and 3.0 billion people with at least 15 percent of such protein. UN’s
Food and Agriculture Organization (FAO) SOFIA 2010
A United Nations Environment Program (UNEP) report
“In Dead Water” published January 2008 said “as much as 80 percent of the world's
main fish catch species have now been exploited beyond or close to their
harvest capacity.” SOFIA 2010 recorded a rise to 85% in the
number of fisheries that are fully exploited or over exploited, depleted or
recovering from depletion.
The world's oceans are already a mere shadow of what
they once were and fish stocks are still dwindling.
Is our food supply, from land and ocean, on your
radar screen?
If not maybe it should be.
Richard (Rick) Mills
rick@aheadoftheherd.com
www.aheadoftheherd.com
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Richard Mills
Aheadoftheherd.com
If you're
interested in learning more about the junior resource market please come and
visit Richard at www.aheadoftheherd.com. Membership is free, no credit card or personal
information is asked for.
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