Posts Tagged ‘Ocean Dead Zones’

The problems that won’t go away

January 10, 2018

Double click to enlarge.

 

Economic injustice is a matter of human relations.  So is the question of war and peace..  They are matters of how we human beings decide to live with each other.

Other problems, such as population growth, climate change and exhaustion of natural resources, are different.  They are questions of how we human beings relate to an external world that is governed by the laws of physics, chemistry and biology, and not by human desires.

The Union of Concerned Scientists published a series of charts 25 years ago (in 1992) about ominous trends in the external world that affect human survival.   Now scientists have taken another look at these trends.  A couple have gotten better.  Many have gotten worse.

One success is the recovery of the ozone layer, achieved by regulation of ozone-depleting substances.   A great achievement not shown on the chart is elimination of famines and extreme poverty in many parts of the world.

Another is the reduction in the birth rate.  In many nations, it is at or below 2.1 children per couple, the replacement rate.  This was achieved by means of the spread of birth control information and the empowerment and education of women.  But birth rates are still high in some parts of the world and, even if this weren’t true , it would still take a generation or two before world population levels off..

In other ways, things have grown worse since 1992.   The concentration of greenhouse gasses continues to increase.  As a result, average temperatures continue to increase.   Deforestation continues.  There is a continued increase in ocean dead zones, where oxygen depletion kills all fish and aquatic animal life.   This means the world fish catch is declining.

This is a great challenge to humanity because there is very little than can be done that will have any impact in the lifetimes of adults now living.  Can we human beings unite?  Do we care enough about coming generations to put their interests first?  Is there still time to act?  I wish I knew the answers to these questions.

LINK

World Scientists’ Warning to Humanity: A Second Notice in BioScience for the American Institute of Biological Sciences.

Winning Slowly Is the Same as Losing by Bill McKibben for Rolling Stone.  [Added 1/13/2018]

A 94-Million-Year-Old Warning About the Ocean’s Future by Peter Brannen for The Atlantic.  [Added 1/13/2018]

The oceans are sick and may be dying

October 24, 2013

Ivan Macfaydan, an Australian yachtsman, sailed from Melbourne to Osaka, and then to San Francisco.  When he took a similar voyage 10 years ago, the ocean was teeming with fish and the skies with sea birds.  Now all he saw was a dead ocean and the only thing he saw was garbage.

mike062620111An interview of Macfayden by an Australian newspaper has gone viral over the Internet.  It reads like the opening chapter of a Stephen King novel.

Scientists meanwhile report that marine life in vast areas of the world’s oceans are dying off and being replaced by jellyfish, a primitive organism that can survive conditions that kill more complex creatures die.  There is a 30,000-square-mile area off southern Africa completely covered by jellyfish, a “stingy-slimy killing field” where no other animal life can survive.

Biologist Lisa-ann Gershwin in a recently-reviewed book that the warming of the oceans, fertilizer runoff from farms, plastic pollution and acidification of the oceans all create an environment that is had for fish, whales, turtles and other higher forms of life, but highly suitable for jellyfish.  Unless something changes, jellyfish will rule the seas and other forms of marine life will disappear.

What is killing the oceans?  Here are some suspects.

Surexploitation_morue_surpêcheEn1Overfishing.  Macfayden encountered a big factory factory fishing ship on his voyage.  The ship’s machinery scoop up everything in the water around them, the crew picked out the tuna, and all the other fish and marine life were dumped.  This is worse than clear-cutting of forests.  This kind of fishing depletes not only the tuna or whatever other species of fish is the target, but it destroys the food chain that the fish need to survive.

The chart at the right depicts the destruction of the Newfoundland cod fishery.  Canadian writer Jacobs wrote that in 1976, Canada’s Department of the Environment responded to the declining catch by deciding to ignore “biological factors” and lift restrictions “in the interest of the people who depend on the fishing industry.”  As the chart shows, the catch increased slightly, then crashed completely.  Since the cod went away, she wrote, fisherman have been encouraged to concentrate on shrimp, crabs and other species lower on the food chain, which jeopardizes the recovery of the cod.

PlasticsInstead of decaying, plastic objects over time disintegrate into tiny pellets that fish mistake for food.  The fish swallow them, the plastic stuff sticks in their gullets or digestive systems, and they can’t digest anything else.  They starve to death.   Unlike with overfishing, cause and effect are not obvious.  Who would have thought that when I use a plastic disposable safety razor, I am contributing to the death of the oceans?

ocean-dead-zonesDead Zones. Excess fertilizer is carried off the land by rain and carried by streams to the ocean.  In the ocean it nourishes a huge growth of algae, and the decaying algae nourish a huge growth of bacteria.  The bacteria suck all the dissolved oxygen out of the water, and the fish die.   This has created huge dead zones is coastal waters and, some suspect, in the deep ocean as well.  Who would have thought that when a farmer in the Midwest grows corn for ethanol production, he could be contributing to dead zones in the Gulf of Mexico.

Other possible causes include the radioactive water from the Fukushima nuclear power plant meltdown, the warming of the oceans due to the greenhouse effect, the acidification of the oceans from burning of coal and fossil fuels and no doubt many other things, known and unknown.

We human beings think that the world’s oceans are so vast that they are in effect limitless, and that human activity will not affect them.  We now know this is a mistake.

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