Most of the toxic substances released into the marine waters provide major hindrances to marine ecosystem. Chemicals and most of the effluent from industries act as poisonous substances leading to extensive adverse effects on marine life. Dead zone is a term used to refer to an area within the ocean affected by hypoxic conditions.
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The condition of hypoxia is created when algal biomass decompose leading to dissolution of oxygen in the water column. This leads to lower concentrations of oxygen within a big percentage of water columns for several months. The five phases of dead zone formation include nutrient-rich runoff, thermal zones, Algae blooms, organic rain then finally flees (Millennium Ecosystem Assessment).
The images shown reveal how ocean colors change from winter to summer. There are massive blooms of phytoplankton extending from the mouth of Mississippi River towards the Texas coast (Millennium Ecosystem Assessment). The dead zones are as a result of river sediments.
The blooms from Mississippi river die and sink to the bottom enabling bacterial composition which eventually deprives the water environment of available oxygen. Such environment makes it difficult for the survival of marine life hence represented by red and orange color symbolizing high concentrations of phytoplankton (Millennium Ecosystem Assessment).
Top Predators are vital in the maintenance of balance amongst sea organisms. Overfishing of large shark species leads to the increased number of rays which are intermediate consumers; these have led to destruction of Scallop fishery (Millennium Ecosystem Assessment). Reduction in the sea lions, because of the overfishing of Pollock fish, led to the increased number of increase in whales assassin hence more predation on sea otters. This resulted in the adverse loss of kelp forest habitat (Arnold 207-219).
|Tuna, Bluefin||4||Avoid||Very High mercury level 0.818 ppm|
|Tuna, yellow fin-pole caught||4||Best||High mercury levels 0.354 ppm|
Yellow fin-Tuna is available in most of the world’s oceans; it is considered to be in abundance and well managed through farming in ocean friendly ways. While, on the other hand, farming of Bluefin tuna leads to destruction of marine life as well as environment (Arnold 207-219).
According to theorist perspective irrespective of which ontological, epistemological position one adopts at one point, there are some negative impacts to be dealt with due to overfishing of tuna. Some perspectives appear better than others; however, there is a need for thorough research capable of generating debatable results in a conservation perspective. Comparison and condensation always guarantee answer concerning such problems and allow understanding beyond theory (Arnold 207-219).
Exxon Valdez oil spill took place in 1989 and BP oil spill of 2010 were recorded as the largest and most devastating releases of oil with adverse effects on ecology. The 2010 BP oil spill occurred as a result of explosion on the Deep-water Horizon drilling rig owned by Transocean ltd (Witters 4).
The spill had profound social and ecological impact while the1989 Exxon Valdez oil spill impacted ecological, economic, social and cultural sectors negatively. Exxon Valdez, a supertanker carrying crude oil rammed into Bligh Reef causing a spill of over 11 million gallons of crude oil. The impact was that over 250,000 seabirds, 140 bald eagles, approximately 20 whales amongst other sea life were victims of damage (Anchorage 5).
The closure of Arctic National Wildlife Refuge (ANWAR) should continue. This is for the purposes of preserving the wide variety of plants and animals present within the coastal plain. The environmental, biological and philosophical quality factors have far much outweighed the economic reasons. The land is estimated to have potential of producing between 11 to 13 billion barrels of oil which was valued to be holding less compared to the giant field at Prudhoe Bay.
Anchorage. 2010. Exxon Valdez Oil Spill Trustee Council 2010, Update on injured resources and services. PDF file. October 18, 2012 <http://www.evostc.state.ak.us/Universal/Documents/Publications/2010IRSUpdate.pdf>.
Arnold, Waltz. “The effects of prey size, predator size, and sediment composition on the rate of predation of the blue crab”. CallinectessapidusRathbun, on the hard clam, Mercenariamercenaria (Linne). Journal of Experimental Marine Biology and Ecology 80 (1984): 207-219.
Millennium Ecosystem Assessment. Ecosystems and Human Well-Being: Current State and Trends. 2005. Web. <http://www.millenniumassessment.org/en/index.html>.
Witters, David. Gulf Coast residents worse off emotionally after BP oil spill. 2010. Web. <https://news.gallup.com/poll/143240/gulf-coast-residents-worse-off-emotionally-oil-spill.aspx/>.