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User:Mav/Destroying the Waters that Sustain Us

Destroying the Waters that Sustain Us
by maveric149
Biology 173

In 1883 Sir Thomas Huxley stated during the International Fisheries Exhibition in London, that "all the great sea-fisheries are inexhaustible." Unfortunately, this has been the primary assumption of most fisheries throughout world history. In fact, the very ability for the Earth to support human life in the future is in danger. The activities of humans are producing harmful changes to the conditions that support life on Earth. One of the greatest challenges that faces humanity, is the wanton destruction of the worlds fisheries. In fact, worldwide, the average person obtains 16 percent of his or her daily animal protein from fish. And unless this and other similar adverse activities are changed, human life will increasingly be miserable for an increasing portion of humanity.

The multitude of threats that are faced by the worlds fisheries are ?caused by patterns of human behavior, particularly over-population and over-consumption.? Alarmingly, the number of overexploited marine fish species has increased from nearly 0% in 1950 to 35% in 1996. Added to this figure is an additional 25% that are near full exploitation. Indeed, many fish species are unable to quickly bounce back after a major population crash ? as has been seen in the cod fishery of the Grand Banks.

In addition to the direct food and materials we harvest from the sea, there are many other so-called ?ecosystem services' derived from the oceans. The marine environment produces oxygen, assists in nutrient recycling, storm protection and climate regulation. For example, the Gulf Coast of the United States lies along five states, which include Alabama, Florida, Louisiana, Mississippi, and Texas. The Gulf Coast is one of the United States' biggest ecosystems and is linked to a sizable part of the nation's economy. In this region, tourism, fisheries, agriculture, and energy resources are the most important parts of the economy. Five of the top ten fishing ports in the US are located here, and the multitude of commercial fisheries within this area produce approximately 2 billion tons of fish, shrimps, oysters, and crabs on a yearly basis. Many natural resources are required to fuel these important parts of the Gulf Coast economy. However, there are many ways that humans can harm the ocean environment that we depend upon. Some of these ways include the destruction of mangroves for shrimp farms, mining coral reefs for building material, the devastation of benthic habitat by trawls, the capture of non-targeted species and the use of dynamite and cyanide to collect shallow-water fish. But, in the case of the Gulf Coast, increasing human populations in the cities that lie along the coast, along with growing demand for the natural resources that the Gulf Coast offers, are to blame for much of its decline.

On top of these critical issues, however, is that fact that decades of overexploitation, environmental abuse, and mismanagement, have degraded the ability of Gulf Coast ecosystems to cope with the increasing demand of ever-larger human populations. Both natural and human-caused climate change has also affected the economy and by extension, the quality of life for the many millions of people who live in this area. What has resulted from this situation is increasing degrees of damage and even the outright destruction of the ecological systems that sustain the natural resources of the Gulf (namely, fisheries).

Furthermore, following the massive flooding of the Mississippi River in 1993, the ?hypoxic (or low-oxygen) "dead zone" in the Gulf of Mexico more than doubled its size?. Now over 7,700 square miles of the Gulf of Mexico cannot sustain large fish species ? there simply is not enough oxygen in the water to support higher forms of life. The reason why this has occurred has been attributed by scientists to be from agricultural derived nutrient runoff from the Mississippi River basin. The way in which this occurs is as follows: During the warmer months of summer and early fall, the agriculturally derived nutrients cause eutrophication which causes high amounts of organic production, that in turn causes huge algal blooms. However, this surge in production goes a bit overboard, and when the algae decompose, oxygen breathing bacteria consume much of the algae and nearly all of the available dissolved oxygen. Scientists refer to the result as hypoxia (literally, ?hypo' meaning low, and ?oxia' referring to oxygen). Unfortunately, reports of hypoxic zones from around the world have been steadily on the rise since the mid '60s.

Both eutrophication and the resulting hypoxia have caused increased mortality of substrate or benthic life forms in a multitude of marine ecosystems and have therefore stressed fisheries all over the world. In fact, some algal blooms are so noxious that they can change the way in which coastal ecosystems function and even threaten the health of human beings. Of course ?Anthropogenic nutrient loading from sources such as agriculture, fossil fuel emissions, and climate events are believed to be related to the global increase in frequency, size, and duration of certain algal blooms.?

Unfortunately, history has shown us that the economic foundation, which underlies fisheries, has continually led to us to overexploitation of fish stocks and the eventual decline of the fishery. Furthermore, there has been very little attention given to the way in which multispecies interactions occur within a fishery. This lack of understanding of fishery ecology is the primary reasons why regulations that are drafted by national and international organizations continue to fail to protect fisheries.

?Fisheries make the largest single anthropogenic impact on the ocean environment.? Pollution cannot equal the subtraction of approximately 100 million tones biomass from the oceans on a yearly basis. Unfortunately, there hasn't been a systematic study on how the yearly fish harvest affects the ecology of the world's oceans (even though there are many examples of dramatic effects such as; changes in fish morphology, shifts in mammal populations seen in the Antarctic, and odd periodic occurrences of large jellyfish swarms? etc). One of the biggest problems is that fishing companies are simply not subject to the same stringent standards as terrestrial companies that harvest equivalent amounts of biomass.

After the collapse of a number of key fisheries around the world by the 1970's, there was an effort to try different fisheries management strategies. For example, statistical analysis was used to show that changes in climate appeared to cause fluctuations in the population cycles of some fish stocks. Unfortunately, the resolution of the models used at that time, could not tell what the underlying factors were that caused the changes. However, in spite of their shortcomings, these early statistically based studies have shown the need for changes in the way in which fisheries science is conducted. Hopefully in the future we will be able to more accurately be able to predict what is actually happening in fisheries. We owe this to ourselves, to the 3 billion more people that will have to be fed in the next 50 years and also to the ecological systems themselves. The oceans have sustained us well in the past, we need to be responsible stewards to make sure they will continue to do so in the future.

Notes and Bibliography

Huxley cited in Tim D. Smith, Scaling Fisheries: tghe Science of Measuring the Effects of Fishng, 1855-1933 (Cambridge University Press, 1994)

Meryl Williams, The Transition in the Contribution of Living Aquatic resources to Food Security FAO Food Agriculture and the Environment Discussion Paper 13 (Washington, DC: International Food Policy Research Institute, April 1996)+

A sustainable future for humanity? How can psychology help? Oskamp S. American Psychology, 2000 May;55(5):496-508

FAO, The State of World Fisheries and Aquaculture, 1996 (Rome: 1997)

Hutchings, J.A. 2000. Collapse and recovery of marine fishes. Nature 406: 882-885.

Taking Stock of Fisheries Management by Timothy R. Parsons,

(Fisheries Oceanography, 5 (3/4), 224-226) 

Climate change and its potential impacts on the Gulf Coast region of the United States. Tchounwou PB. Environmental Health 1999 Apr-Jun;14(2):91-102

The dead zones: oxygen-starved coastal waters. Joyce S. Environmental Health Perspect 2000 Mar;108(3):A120-5

Taking Stock of Fisheries Management by Timothy R. Parsons,

(Fisheries Oceanography, 5 (3/4), 224-226) 

Taking Stock of Fisheries Management by Timothy R. Parsons,

(Fisheries Oceanography, 5 (3/4), 224-226) 

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