Humanity is Dependent on our Oceans which are in Great Danger

Our Earth is under threat including disaster in the oceans

Commentary by S. Tom Bond, Resident Farmer & Retired Chemistry Professor, Lewis County, WV

By this time everyone (unless they have their head in the sand) knows about climate change, but what is less well known is the disaster going on in the Oceans.

We know that certain gases produced by humans intercept radiation from the sun and convert it into heat, warming the atmosphere. Ninety percent of the heat goes into the oceans, most of the rest into melting glaciers and ice caps, warming the bare earth and warming fresh water. Only a few percent goes into warming the air, which is the temperature change we measure for global warming. More about that later in this article.

We are doing a lot of other things to the oceans:

(1) Most fish stocks, shell fish and edible mammals are being depleted by over-fishing. Island nations, like Japan and sea coast dwellers eat a lot of fish. Fishing is as mechanized as farming. Huge ships equipped with nets take fish and other huge ships take whales. All work them up at sea, and dump the unwanted parts. This upsets the chain of prey and predators, decreasing production, and so many are caught in many places that insufficient juveniles are left to keep the rate of reproduction up.

(2) In many places “dead zones” have formed where there is not enough dissolved oxygen in the water to support life. Some 400 are known to exist. Some are caused by dumping barges of urban sewage, some to fertilizer and pesticides. In some places, warmth and algae blooms from fertilizer poisons the surface. Until Congress banned ocean dumping of sewage sludge in 1988 New York City dumped millions of tons of its sewage in the ocean. Other places, outside the U. S., continue to do it now.

(3) Mercury is a notorious poison released by burning coal. It is converted into compounds soluble enough to wash down stream, poisoning fish which concentrate it, and then into the ocean where it becomes concentrated enough to poison people who eat those fish. Tuna, which are a predator, is famous for having a high mercury concentration. Mercury is a nerve poison.

(4) Plastics, made from fossil fuels, floats. Tons of it are being dumped in and near water all over the world. In many places the streams, small and large, have conspicuous plastic pollution. Little is removed, and in time it works its way down to the oceans, which have polluted harbors and beaches. it is a rare beach which does not have this kind of litter, unless it is removed by cleaners. Huge gyers, patches of floating plastic, bottles toys to structural elements, are found in the ocean.  The worst is known as the Great Pacific Garbage Patch.

Plastics contain compounds which causes it to break up into tiny pieces through UV radiation. This works well on land, having little effect on the soil it is incorporated into. At sea, when the particles get about the size of the period at the end of this sentence, many of them mix downward and are consumed by small fish, shrimp, etc., and then it gets into larger fish when the smaller ones are eaten. Many are consumed by sea birds, too. This damages the fauna, reducing the reproduction rates, reducing their ability to escape predators as well as affecting general health.

(5) Carbon dioxide is somewhat soluble in water, too. It is in equilibrium, thus as more enters the air, more dissolves in water. It reacts with the water forming carbonic acid, and this affects much ocean chemistry. It is strong enough in places to dissolve the calcium carbonate that forms the shells of oysters, clams, and so forth. The result is that these creatures die, or have weak defenses against predators.

(6) Of particular concern is the effect on coral. Corals are spectacular, diverse ecosystems. Many species live in the protection of the coral representing a huge community of sea life. They are said to be the ocean equivalent of the tropical rain forest, many kids of the plant like corals, (which are actually animals which cannot move due to their calcium carbonate skeletons) supporting and protecting many, many kinds of fish and other animal life. Many corals have a symbiotic relationship with algae, which react with carbon dioxide dissolved in the sea water, using sunlight, to provide energy rich sugars and fatty acids. More on corals here.

When the water is too warm, the corals expel the algae, becoming white and the corals die. Then the acid sea water dissolves the skeletons and the whole ecosystem disappears. Twenty five percent of the world’s marine species are associated with coral reefs. More here.

Back to direct problems caused by global warming. When water warms, each degree Fahrenheit increases its capacity to hold water 4%. The average temperature rise since 1880 is about 1.53 degrees Fahrenheit. The world’s average increase in moisture content of air is about 6%. Of course, in some places the surface of the ocean has warmed much more than that. This is the reason Louisiana had 26 inches of rainfall in one area in two days, and Haiti had 15 inches. Storms that once were 100 year storms are now common.

The heat absorbed by the ocean water enters at the point air and water are in contact, the surface. However, water is liquid and circulates. Many layers are involved. The heat is drawn in time to the depths, and moves all over the world. Some of it reaches Antarctica. The main melting in the Antarctic is on the under sides of glaciers which extend into the ocean. However, as the ice breaks off it loosens up the ice on land which in turn slides toward the ocean. The projected rise in sea level comes from the volume of this Antarctic ice and the glaciers on Greenland. The Arctic is deep ocean and since the ice there floats, it does not raise the sea level as it melts. Details here.

Some of the heat that enters the ocean goes around the northern continents and warms the deep sea areas there. In these places is a vast store of methane, a far worse green house gas than carbon dioxide, buried in methane clathrates. These are crystals of water and methane. They require cool temperatures and pressure to form. The methane comes from decayed matter in the sediments, formed over long periods of time, and some from seeps of natural gas deposits. When pressure goes off or they are warmed, the clathrate breaks down, the methane bubbles to the surface and enters the atmosphere. As this happens on a large scale, it will increase global warming significantly.

In less than a decade the floating ice on the Arctic ocean is expected to disappear in late summer. At present the ice reflects radiation and insulates the surface. The trend is less and less ice each year. When it is all gone, more heat will enter the ocean there. It will freeze over each winter, but it will be open for shipping year around. How this will affect currents and clathrates is anybody’s guess.

The oceans cover three-fourths of the earth’s surface, and most of us do not see any of it. But these problems threaten us all. It is part of one of the most important problems that faces the human race, namely global warming. Only large scale war or nuclear war and the population explosion rival it.

Tagged as: climate change, global warming, ocean impacts, plastics, sea level rise