Our Starving Oceans, The Decline In Plankton

Our Starving Oceans:

The Decline in Plankton

Plankton refers to the whole assortment of tiny, often microscopic, living things in the ocean. These organisms are the starting point, or bottom of the marine food web, and the health of the whole system depend on sufficient plankton levels. There are two primary types of plankton that scientists have been concerned with are phytoplankton and zooplankton. Phytoplankton is the fertilizer for the zooplankton supplying them with important nutrients to survive. Many fish and some mammals depend on them for their food source. As a result, animals higher on the food chain are facing mass starvation. Besides the fact of them being the fundamental food link for the ocean phytoplankton also contributes to the global production of oxygen and carbon dioxide absorption.

Researchers have been observing the trends in the plankton for about 70 years. Sir Alister Hardy invented the Continuous Plankton Recorder Survey or CPR for short in 1931. Robert Falcon Scott first used the CPR on the British Royal Research Ship on his expeditions to Antarctica (Kreeger, Gamble 32). The device would record the abundance of plankton in a predetermined volume of water. Hardy had determined that if he deployed several of these devises he could trace seasonal and annual changes in abundances. This data was used to provide a unique base line to compare fluctuations in fish abundance and suspected environmental changes. Mike Colebrook, former director of the survey explains:

As the CPR Survey grew over the decades, in terms of the routes it covered and the decades it spanned, the value of the data has totally transcended the original concepts. Today, the survey is tackling phenomena as large as global climate change. (Kreeger, Gamble 33)

There is an extraordinary list of statistics that convey the survey's history. The CPR has traveled nearly 4,000,000 miles; that's over 150 times around the world by ships from 10 different countries resulting in over 165,000 samples as of 1992. Some of the routes the CPR has traveled were in the North Sea, North Atlantic, English Channel, and along the North American eastern seaboard. In the North Sea the data on fisheries David Cushing a biologist had discovered the link between the abundance of fish and plankton (zooplankton) a favorite food of juvenile fishes. The data collected over 15 years 1962-1978 had indicated the production of plankton had shifted from April to May. This changed the commercial wealth of important fish such as cod and haddock.

In more recent years technology has given us the capability of viewing the earth's atmosphere via satellites. Coastal Zone Color Scanner (CZCS) aboard NASA's Nimbus-7 Satellite used in late 1979-1986 to measure carbon per year. Also there is NASA's Sea-viewing Wide Field-of-view Senor (SeaWiFS) used in 1997-2002. The SeaWiFS measures the amount of light coming out of the ocean at different wavelengths on the spectrum, and can determine the strength of the greenness coming form the tiny plants' cells (Staff Writers). Researchers have claimed that the plants productivity has been declining since the early 1980's throughout the world's oceans. The microorganism phytoplankton in our oceans, account for about half the transfer of carbon dioxide from the environment into plant cells by photosynthesis. Land plants pull in the other half. Therefore in our atmosphere CO2 is a heat-trapping green house gas. So the result of the declining plankton causing less photosynthesis the effect then is the increase of atmospheric CO2. Scientists have discovered that the result then of the seas getting warmer would interfere with the vital upward movement of nutrients from the deep sea. This in turn would starve the essential plankton, which is at the base of the marine food chain. This could have catastrophic implications for the entire marine ecosystem. Watson Gregg, of NASA's Goddard Space Flight Center had stated:

It's difficult to say what the implications are, but they could be pretty significant. The whole marine food chain depends on the health and productivity of phytoplankton. (Toner)

Researchers having also been studying the plankton levels off the shores of California for the past 50 years. John McGowan a marine biologist at Scripps Institution of Oceanography has studied the California current had found that the abundance of plankton has dropped about 70 percent in the past 20 years, which has had a ripple effect on the local species. These species depend on the plankton for food. Sea birds have declined 70 percent and there was a 50percent drop in fish larvae. (DeSeve 8)

Let us examine the geographic determinant in relationship to the decline of plankton. The increase in global warming has on the Artic polar icecap melting which could potentially lead to a lull in the Atlantic Conveyer current that pushes warm water to northern Europe, causing a decline in plankton and consequently, the supply of fish. This is resulting in a global change in geography. Marine species are very sensitive to fluctuations in temperature changes in climate and atmosphere conditions create high risks to them. There is evidence showing the thinning of the ozone layer above the Antarctica. Ultraviolet-B radiation is able to penetrate the waters affecting the photosynthesis and the growth of phytoplankton. This also is going on in shallow waters, including areas off the cast of Florida and the Bahamas. This is striking the organism at its most vulnerable stages of life. Since higher temperatures cause the water to expand, a warming world may generate violent and frequent storms. With these storms come intense waves and winds eroding at our costal barriers, seawall and levees that protect our many coastal communities. Massive thawing could provoke flooding of coastal areas worldwide. This could catastrophically change the world geography, as we know it leaving much of our prime real estate underwater.

The cycle of flooding will probably be permanent in some cases such as in the Chesapeake Bay. Here the rising sea levels have been eroding the beaches and the wetlands. Blackwater National Wildlife Refuge has lost close to one-third of its land area over the past three decades, and many once rich bottomland farms are now either water logged or too saline to sustain crops (Hinrichsen 56). Louisiana has been losing between 24 and 40 square miles of coastal land each year for the last four decades (Fujita 21). Recent studies suggest that the areas that will be most devastated are the tropics and warm temperate regions, which are heavily populated. The Mediterranean's southern coast, west coast of Africa, South Asia (India, Sri Lanka, Bangladesh, and the Maldives), all coastal states comprising Southeast Asia, and low-lying