The ocean is one of the largest ecosystems on earth. According to data collected from National Geographic, five oceans make up 71 percent of the earth’s surface (Jakasha, 2009). According to the National Geographic scientist Jakasha (2009), 80 percent of life on earth resides in the ocean; the majority of these life forms live close to the ocean’s surface as it is easier to find food. In addition to the numerous life forms that exist in the ocean, this ecosystem is also home to a variety of habitats such as shores, kelp forests, mangroves, estuarine habitats, coral reefs and polar seas; scientist have found that marine inhabitants travel between these habitats at different stages to feed, and give birth (Jakasha, 2009).
For several decades, marine biologist have expressed concern about the harmful effects that agriculture, specifically fertilizer deposits can have on ocean ecosystems. In 2005, Stanford University Researchers began to suspect that fertilizer deposits from large farms can create spontaneous growths of “marine algae that disrupts the ocean ecosystems and produces dead zones in the sea”; they conducted a study that found the “first direct evidence linking large-scale coastal farming to massive algal blooms in the sea” (Shwartz, 2005).
According to the author Biello (2008), the ocean’s ecosystem is becoming enriched with nitrogen which is normally in short supply. Biello (2008) states that limited nitrogen also limits the creation of new organic matter, also known as biomass and phytoplankton; they are the tiny plants at the bottom of the marine food chain. However when agricultural fertilizers cause oceanic ecosystems to become enriched with nitrogen, organic matter populations can cause algal bloom (Biello, 2008) . In an normal ecosystem, when organic matter dies it sinks to the bottom of the ocean where it undergoes the natural process of decomposition and is eaten by oxygen-consuming bacteria (Biello, 2008). When agricultural pollutions increase nitrogen levels, this creates low oxygen, or ‘hypoxic’, conditions; according to Biello (2008), creatures such as fish, crabs and shrimp can usually avoid these areas. Organisms that are slower may die or become nutrient deficient ; as a result fish have less access to food that can be found on the ocean floor and they lose food sources. Biello (2008) also suggests that long term low oxygen conditions can permanently alter an ecosystem’s biodiversity by changing the types of plants and animals that can live there.
The ocean is also viewed as a source of recreational activity for most people; they have used the ocean for these purposes for centuries. The ocean is also used as a source of food, transportation, and employment. In the U.S., the Environmental Protection Agency, the U.S. Coast Guard, and state marine regulatory agencies work collaboratively to regulate ocean water sports that include; fishing, skiing, boating, and swimming. There are also several international laws that limit activities such as fishing. Most people’s recreational activities are not harmful to the ocean; however the EPA has found that unauthorized over harvesting of ocean foods and the introduction of marine pests can have harmful effects on the ecosystem.
The EPA is concerned about over-fishing in the ocean because it is a valuable renewable resource.
According to Jakasha (2009) every year, people harvest around 80 million tons of marine organisms the ocean and if this harvest is managed properly, the oceans can continue to feed people for the unforeseeable future; however more than 70 percent of coastal and deep-sea fisheries are being over-fished and other species suffer because their members are caught accidentally and then discarded. In North American, 82 marine species are at risk of extinction (Jakasha, 2009). Coastal population growth and pollution also contribute to the demise of coastal fisheries. The ocean also has valuable nonrenewable resources, crude oil and natural gas; unlike ocean life which when regulated can be replaced, crude oil and natural gas cannot be replaced or will be replaced at very slow rates. According to Jakasha (2009) about one-third of the world’s crude oil and one-quarter of natural gas come from offshore sources. These non- renewable resources are important because they can be refined to distill gasoline, diesel, kerosene and other fuels; these fuels are used to create important sources of energy. However, offshore drilling is very dangerous to the ocean’s ecosystem because it rapidly decreases non-renewable resources and potential oil spills can severely damage marine life.
To protect the oceans’ renewable resources, according to Jakasha (2009), there are several federal and international laws that limit how much fish can be taken from given areas each year; others restrict the types of equipment that can be used by commercial fishing operations. These restrictions aid coastal fisheries in protecting the world’s supply of fish. In 1972 Congress passed the Federal Water Pollution Control Act which gave the Environmental Protection Agency (EPA) the power to protect the United States oceanic waters; the Federal regulation, in consultation with Federal, State, Tribal and local partners, are one of the fundamental tools the EPA uses to implement environmental policies designed to protect the ocean’s ecosystem (Ocean Regulatory Programs, 2012). According to the EPA they use federal regulations to manage, protect, and restore water resources of the United States, including aquatic ecosystems of coastal watersheds and the oceans (Ocean Regulatory Programs, 2012).
- Biello, D. (2008, August 15). Oceanic dead zones continue to spread: Scientific American. Scientific American. Retrieved July, 2013, from http://www.scientificamerican.com/article.cfm?id=oceanic-dead-zones-spread
- Jaksha, A. P. (2009). Biodiversity in the ocean. In One ocean: A guide for teaching the ocean. Retrieved July, 2013, from http://education.nationalgeographic.com/media/file/one-ocean-chapter3.pdf
- Ocean Regulatory Programs. (2012). U.S. Environmental Protection Agency. Retrieved July, 2013, from http://water.epa.gov/aboutow/owow/programs/index.cfm
- Shwartz, M. (2005, March 10). Ocean ecosystems plagued by agricultural runoff. Stanford News. Retrieved from http://news.stanford.edu/news/2005/march16/gulf-030905.html