El Nino Overpowers The Water example essay topic

El Nino's Wrath Microscopic, photosynthetic phytoplankton produce seventy one percent of the world's Oxygen. A reduction in the world's phytoplankton population would be detrimental to all terrestrial and aquatic life. The event known as El Nino-Southern Oscillation (ENSO) is a complex interplay between the ocean and the atmosphere causing a reversal in the trade winds, which in turn moves warm water masses to opposite sides of the Pacific Ocean. Better known for it's atmospheric effects, El Nino also plays an important role in reducing the phytoplankton population. El Nino halts the process of upwelling, which moves nutrient rich water from the deep, up to the surface. Upwelling is essential for the production of phytoplankton.

Without phytoplankton as the base of the food chain in the ocean, all other aquatic life would cease to exist. El Nino can be attributed to the increase of global warming caused by Carbon Dioxide emissions into the atmosphere. El Nino will continue to increase proportional y to the Earth's rising temperature and thus, reducing the world's phytoplankton population; resulting in catastrophic ecological effects as the base of the ocean's food chain continues to be destroyed. Winds affect upwelling. Winds that blow along the coasts of North and South America drag the water along with them.

"The Earth's rotation then deflects the resulting surface currents away from the coastlines". (Wallace 11) Because the surface water moves away, colder, nutrient-rich water comes up from below and replaces the previous warm water, a phenomenon known as upwelling. (Wallace 11) Basically, the wind blows towards the equator and the rotation of the Earth pulls the water away from land similar to the way a cube of ice stays in one place as you rotate a glass of water. The glass could be interpreted as the Earth, and the ice cube as the mass of water. Relative to the glass, the ice or water stays in one spot as the glass or Earth rotates around. The winds that blow along the equator also affect the properties of up welled water and also the food chain.

"Without wind, the dividing layer between the warm surface water and the deep cold water, known as the thermocline, would be nearly flat; but the winds drag the surface water westward, raising the thermocline nearly all the way up to the surface in the east and depressing it in the west. The cold water below the thermocline is rich in nutrients". (Wallace 12) This is important to the organisms because they do not have to dive very deep to search for food. The lower the thermocline, the less energy they have to waste hunting for food. Phytoplankton are the most important organism in the ocean. In the presence of sunlight, a microscopic plant species called phytoplankton use the nutrients from upwelling to grow and proliferate.

"Phytoplankton are thought to bind at least thirty five billion metric tons of carbon into carbohydrates each year, at least forty percent of the food made by photosynthesis on Earth". (Garrison 342) For this reason, phytoplankton are considered the base of the food chain in the ocean. El Nino destroys the upwelling process. During an El Nino, the air pressure between the western and eastern Pacific becomes much more even, resulting in much calmer winds blowing from east to west. (El Nino on Fish of the Eastern Pacific 1) "In effect, a wave of warm water is generated that propagates eastward a ross the Pacific. This movement brings eastward a lens of warm surface water that increases the sea surface temperatures, and shuts down the upwelling system of nutrient-rich cool water from below".

(Levinton 23) The counter current created from El Nino overpowers the water moving away from the Americas. The result is no net movement of water away from North and South America. This reduces the amount of water displaced along the coast and subsequently the amount of water from depth which must replace it, decreasing upwelling and as a result the concentration of nutrients reaching the depth at which phytoplankton photosynthesize. (Effects of El Nino on Fish of the Eastern Pacific 1) El Nino devastates the ocean's natural upwelling process.

The process of upwelling is important to the survival of phytoplankton. A decreased wind magnitude associated with El Nino decreases upwelling. "During an El Nino, the air pressure between the western and eastern Pacific becomes more even, resulting in much calmer winds blowing from east to west. (Effects of el Nino on Fish of the Eastern Pacific 1) Thus, the stronger the El Nino, the less water will be moved. If the conditions persist, the water will soon be depleted of the chemical nutrients available for phytoplankton production. "The surface waters above the thermocline would soon become deprived of nutrients were they not continually being replenished by upwelling".

(Wallace 14) The situation is analogous to a field of grass. The grass can be thought of as the phytoplankton. If the grass is deprived of nutrients such as water, minerals, and sunlight, the grass will eventually die off. Phytoplankton are forced to migrate to a region where nutrients are abundant for survival. This migration is a result of El Nino decreasing upwelling. "Lack of nutrients at the surface, in addition to increased Sea Surface Temperature results in a migration of the phytoplankton layer".

(Effects of el Nino on Fish of the Eastern Pacific 1) The migration of the phytoplankton would be similar to the field of grass growing in another location where sources of nutrients are plentiful. The phytoplankton actually migrate to deeper, colder water where they can find necessary nourishment. "The warm, nutrient-poor surface waters brought by El Ninos can sustain few phytoplankton". (Biological El Nino Effects 1) Grass is more likely to grow in the Great Plains than in the Sarah Desert. However, the warm water mass can destroy the phytoplankton. "The warm water that accumulates causes the death of cold-water organisms that are the basis of food chains for many marine fishes, mammals, and bids".

(Karleskint 69) Now these animals may die because they lack a food supply. This seems to be a trade off between vital nutrients. They have to spend more energy searching for food than the energy they consume. Migrating for food is less efficient than remaining in one place and consuming a sufficient food supply.

All aquatic life is dependent upon phytoplankton. Phytoplankton are the base of the food chain in the ocean. "Marine environments are rich in phytoplankton, and the organic molecules these microscopic algae produce are a key source of food in all aquatic environments". (Campbell 341) Phytoplankton is to the aquatic food chain as plants are to the terrestrial food chain. The analogous grassy field can represent this oceanic food chain.

Nutrients limit the grass growth, and the grass will only grow where nutrients allow. The primary consumers of this grass such as rodents are forced to migrate also. If the grass grew on the side of mountain midway up the mountain, the rodents would have to travel vast distances and overcome extreme temperature variations each day to feed on that grass. The rodents would spend so much energy traveling each day; they eventually would perish. Zooplankton, the primary consumers of the ocean start to die as the reduction in phytoplankton numbers reduces the available food sources.

"The Most abundant, accounting for about seventy percent of individuals, are tiny shrimp like animals called copepods". (Garrison 351) The copepods eat the phytoplankton, and almost every marine herbivore eats copepods. If the copepod numbers drop, the effects on other populations will be detrimental. "Scripps Institution of Oceanography researchers reported an eighty percent decline in zooplankton along California's coast between San Diego and a point just south of San Francisco. They believe the loss is due to the one to two degree Celsius rise in temperature since the early 1950's due to El Nino warming's. (Hill 1191) Thus, the reduction in copepods means that fish, marine mammals, and sea birds have to migrate elsewhere to find a source of food.

This prompts their abnormal migration away from the equator towards colder, nutrient rich water. The last few major El Ninos demolished the Ocean's food web, major fisheries and devastated other parts of the globe. First, ENSO ravished Peru's fishing industry. "Between 1957 and 1976, anchovies accounted for ninety percent to ninety eight percent of all Peruvian landings.

The 1972-1973 El Nino warming killed that year's juvenile anchovies or drove them off into colder southern seas, the fishery's population dropped dramatically in Peruvian waters and still has not recovered". (Tidbits 5) After two decades, Peru is still affected by the 1972-1973 El Nino. The anchovy population will probably never fully recover because the increasing numbers of El Nino occurrences will continue to destroy the anchovies. El Nino hit Peru a decade later wreaking havoc on the inland valleys and fisheries. "During the El Nino of 1982-1983, about six hundred people died from intense storms and Peru lost about two billion dollars from fishing losses and storm damage". (Levinton 23) El Nino's intensity has increased over the past couple decades.

More damage results as the Earth warms and increases El Nino's magnitude. Last year's ENSO event was the most destructive to date. "Estimates of worldwide 1997-98 ENSO-related damage exceeded twenty five billion dollars". (Garrison 216) If the atmosphere continues to warm, the intensity of ENOS events will increase.

Global warming aids El Nino's wrath. El Nino events will be more frequent and last longer as the Earth's atmosphere continues to warm. As people cut down forests and burn fossil fuels, carbon dioxide is released into the atmosphere, helping warm the planet. Now, some scientists are asking whether El Nino's recent long stays could be related to global warming. (Tibbetts 2) "A warming climate could bring longer, stronger El Ninos" (Tibbetts 3) Thus, the ocean's food web will continue further decline as more phytoplankton die, and starve higher members of the food chain. In conclusion, El Nino halts the process of upwelling, which provides nutrient rich water to the surface essential for phytoplankton production.

Phytoplankton are the primary source of food in the ocean. Upwelling is imperative to the phytoplankton's population and helps sustain large numbers of phytoplankton vital to the rest of the food chain. When El Nino stops upwelling, the rest of the food chain is affected. Fish populations decline and sea birds are forced to migrate towards the poles. The world's fisheries are therefore affected.

Increasing global warming will increase the number of ENSO events. As a result, El Ninos will become more powerful, last longer, and cause more destruction worldwide..