Dead zones
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Dead zones – regions where conditions cannot sustain most organisms -- have been appearing and expanding in the ocean environments. A dead zone is an area in the ocean that becomes hypoxic, meaning low in oxygen, which cannot sustain most forms of life, including fish and crustaceans. In a hypoxic zone, marine life is killed off or must migrate to different areas in order to survive. Currently, roughly 400 dead zones have been identified all across their world. Today, dead zones can be found in numerous locations: the Puget Sound, off the east coast of the United States, in the Gulf of Mexico, off the coasts of China, Japan, Brazil, Australia, and New Zealand, the Baltic Sea, northern Adriatic Sea, the Yellow Sea, and the Gulf of Thailand, and so forth [1]. If dead zones continue to expand throughout our oceans, we could have a substantial loss of the diversity of marine and aquatic creatures. The impacts of dead zones are analagous to the loss of rainforest ecosystems, as delay in taking action may lead to a greater loss of our biological heritage.
“The Dead Zone poses an enormous threat to the biodiversity, ecological integrity, and fishery productivity of the Gulf of Mexico” [2]. The approximately 400 dead zones noted around the world is said to be around a 50% jump of the 200 estimated that occurred in the end of 2006. which was a 34% increase from 2004, according to a recent United Nations.
These dead zones are initiated by an increase in chemical fertilizers, which begina process known as eutrophication. Eutrophication is where bodies of water “receive excess nutrients that stimulate excessive plant growth” [3]. The chemicals that are typically increased are nitrogen or phosphorus [4]. This problem also causes decreased biodiversity, changes in species composition and dominance, and toxicity effects [4]. The chemical fertilizers come from farms, run off from residential and commercial lawns, poorly operated water facilities and sewage. Dead zones are typically located in standing bodies of water, fjords, or in coastal areas where the water flow is restricted, as compared with the middle of the ocean, where dead zones do not occur. The chemicals “cause algal blooms that literally eat up much of the available oxygen, leaving the affected waters at less than 2 parts per million dissolved oxygen, making it impossible for aquatic life to survive” [5]. Oxygen levels of 2 parts per million are needed in order to sustain the lives of commercial fish, crab and shrimp species [2]. When these large quantities of algae die, they will sink to the bottoms of the ocean floors and decompose. The deep waters where this happens take a long time to become reoxygenated. Dead zones usually develop every spring and summer, although some of these stick around year round. They tend to deplete and during these times reoccur as well [6].
[edit] 1 Dead zone events in Hood Canal, WA
In Washington State, the Hood Canal (not actually a canal but a fjord) suffers from frequent dead zone events. Because Hood Canal is a fjord, it does not allow water to exchange very easily [7]. In 2003, it was listed as one of the two dead zones located along the West coast of the United States, with the other occurring in California’s Los Angeles harbor. The problems that are unfortunately happening in the Hood Canal are not completely the fault of human actions, but of Mother Nature as well. Human effects aside, other natural effects that alter the canal are light from the sun, wind, and conditions from the outside oceans effect what is going on [8]. In some of the areas in the canal, it can take up to a year for the water to be cycled out [7]. Also, the natural rise of the lower, less oxygenated water into the surface water affects the oxygen levels in the surface water. The lower levels of the water are where the chemicals and fertilizers start effecting things. When deoxygenated water begins to rise to the surface, this creates a fatal situation for fish and other marine animals that live in these higher water layers.
Apart from the natural effects, there are the human ones as well. The Hood Canal suffers from issues with leaky septic tanks. Over the last 30 years, the population of the Hood Canal has grown both in number, and in the number of year round residents. This area used to be more populated by visitors with seasonal homes, but as the years have progressed the area has ha a larger constant population. With the increase of inhabitants, the use of the septic tanks has increased as well. These septic tanks along the water have been shown to be leaky and faulty. Since most residents are right along the water, the sewage has been leaking in the ground which flows its way into the water and comes up in the water. Other factors that lead to the entrance of pollutions are auto emissions, storm run offs, and fertilizers. There has been talk of building sewers for the hood canal communities, but this may entice more people to move to the area and with increased population, there is always an increase in pollution as well. There is a plan to clean up the Hood Canal but in order to do this we need cooperation from the landowners, as well as many other in order to take this problem and contain it.
[edit] 2 Dead zones in the Gulf of Mexico
This process of fertilizer-initiated eutrophication has been depleting oxygen, causing tens of thousands of miles of the dead zones all across the world [9]. The reason why the Gulf of Mexico has such a huge dead zone is due to the fact that enormous size of the river and its watershed, and the very large number of farms and residents from which fertilizers run off and make their way into the Mississippi, traveling downstream into the Gulf. Every year, over 1.6 million tons of nitrogen is flowing out of the Mississippi Basin into the Gulf. There seems to be a correlation of the increase of fertilizers to the increase of the dead zones we see. Annually, common farming states in the lower United States near Mississippi, such as Ohio, Indiana, Illinois, and Iowa, will drain their wetlands to continue their farming. All this released water will make its way into the Mississippi and out through the basin in the Gulf. It is said that the dead zone located in this area has apparently doubled in size in the past 20 or so years [6].
[edit] 3 Other prominent dead zones
Outside the United States, new dead zones have been found at the Archipelago Sea in Finland; Fosu Lagoon in Ghana; Pearl River estuary and Changjiang River in China; and Mersey River estuary in Britain; the Elefsis Bay and Aegean Sea in Greece; Paracas Bay in Peru; Mondego River in Portugal; Montevideo Bay in Uruguay; and in the western Indian Ocean [9].
[edit] 4 What can be done?
Can dead zones be reversed? Although it takes great work, effort, awareness and cooperation by many to succeed, there have been examples of areas working together to reduce or eliminate dead zones. In regards to the chemicals and such being leaked into the Gulf, many states that affect the Mississippi are trying to regulate nutrient standards. The problem is that this isn’t something mandatory at this time, only just voluntary. Many new approaches need to be addressed and created in order to protect the water quality of what is being leaked into the Mississippi River and out into the Gulf. Another way, in not just the states, is for farmers to reduce the amount of fertilizers they are currently using in their crops. An approach that is being looked at in Europe is cutting the emissions from wastewater treatment plants and industries. Becoming educated is a great way to help with the impacts of dead zones. Although they are able to be reversed, this process is very difficult. An alarming figure to leave you thinking is from the Discovery Channel. It is estimated that “By 2030, the world's rivers will pump 14 percent more nitrogen into seas and oceans than that found in the mid-1990s, according to new U.N. research released at a meeting in Beijing” [9].
Here in Washington we are currently coming up with and working on ways in which we can decrease our Hood Canal dead zone. Our state representative Christine Gregoire has stated a two year plan to help us clean up our canal. The serious factor we have getting in our way is that the dead zone in the Hood canal is not just solely caused by human influence. Although this may be the case, it is stated that “Up to 320 tons of nitrogen is added to the canal annually from human sources – and the major contributors are septic systems (60%), livestock manure and salmon carcass disposal (27%) and storm water runoff (11%)” [10]. Her plan includes improving the management of sewage in Belfair and the Hoodsport areas, Identify failing septic systems, help homeowners and business owners fix failing septic systems, keep salmon carcasses out of the canal, manage animal waste, complete a storm water plan for Hoodsport and Belfair, fix state facilities, continue scientific investigation of Hood Canal, and one of the most important being public education.
One way in which we can start is with the cattle famers and the crop famers. If the cattle famers that have their livestock in the valley start to go organic, this can reduce some of the waste that these animals are producing that is leaking into the canal, and if the crop farmers start going organic, they can help reduce the fertilizers that are being spread as well.
In 2002, drastic numbers of fish and other marine life started dying on which got the attention of UW researchers and state environmental. Already, there has been $21 million dollars put into funding to work with decreasing the Hood Canal dead zone. Of the $21 million, 16 is being used to build a new sewer system in Belfair, 1 million is going to design a sewer system for the Skokomish Tribe and city of Hoodsport, $1 million in low-interest loans to help repair failing septic tanks; $470,000 to identify failing septic systems. To add to that, there has been money to reduce livestock waste and to improve the disposal of salmon carcasses.
This is a start for our state, and with a start like this and more public education, the dead zones not just here in Washington, can start to be cleaned up as well. People need to start to know and see the consequences of what is happening out in our oceans and how things are constantly dying off. Start today and become more aware of what is actually going on out there in our worldly waters, for the youth of today might be the core of the population to make the change we need to see. [11]. [12]. [13].
[edit] 5 References
- ↑ http://www.grinningplanet.com/2005/05-17/gulf-of-mexico-dead-zone-usa-global-article.htm
- ↑ 2.0 2.1 http://www.sierraclub.org/cleanwater/waterquality/deadzone.asp
- ↑ http://toxics.usgs.gov/definitions/eutrophication.html
- ↑ 4.0 4.1 http://en.wikipedia.org/wiki/Eutrophication
- ↑ http://harmanonearth.wordpress.com/2008/04/08/dead-zone-of-our-own/
- ↑ 6.0 6.1 http://seattletimes.nwsource.com/html/nationworld/2008115230_deadzones15.html
- ↑ 7.0 7.1 http://www.kcts9.org/video/psm-hood-canal-dead-zone
- ↑ http://crosscut.com/2008/09/23/puget-sound/17994/
- ↑ 9.0 9.1 9.2 http://dsc.discovery.com/news/2006/10/20/deadzone_pla.html
- ↑ http://www.governor.wa.gov/news/news-view.asp?pressRelease=33&newsType=1
- ↑ http://community.seattletimes.nwsource.com/archive/?date=20050319&slug=hoodcanal19m
- ↑ http://www.harvestcleanenergy.org/enews/enews_0405/enews_0405_Hood_Canal_Digester.htm
- ↑ http://www.kcts9.org/video/psm-hood-canal-dead-zone
