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Unit 3 “Oceans, Coasts, and Fisheries” Oceans on the Earth • 71% of Earth’s surface is covered by oceans • Composition of ocean water is as follows: – 96% water – 3.5% salt (mostly NaCl – sodium chloride) – .5% consists of trace amounts of Sulfate, Mg, Ca, K, and Bicarbonate Oceans on the Earth • As depth increases, pressure _________. Why? • As depth increases, temperature __________. Why? • As depth increases, salinity _________. Why? • As depth increases, light penetration decreases Movement of Ocean Water • Currents – large volume of ocean water that flows due to changes in density, temperature, gravity, and wind – Horizontal currents: usually due to wind – Vertical currents: due to density, temperature, and gravity Movement of Ocean Water • Upwelling - vertical flow of cold, dense water to the surface; occurs in areas where horizontal currents diverge • Downwelling – vertical flow of warm, less dense water toward the ocean bottom; occurs in areas where horizontal currents converge Movement of Ocean Water • It is important to understand the interconnectedness of air currents (wind) and ocean currents – Air currents affect horizontal ocean currents and horizontal ocean currents affect vertical ocean currents – Therefore, a change in meteorological conditions can affect/change ocean conditions Ocean’s Vertical Zones Ocean’s Zones Continued Ocean Currents Summary • http://www.youtube.com/watch?v=Hu_Ga0JY FNg&feature=related • http://www.youtube.com/watch?v=L9zjmC8In KA&feature=related • http://www.youtube.com/watch?v=FuOX23yX hZ8&feature=channel Marine Habitats • The ocean contains a great variety of species that include invertebrates and vertebrates • There are two categories of marine habitats: – Benthic: the ocean bottom in either shallow or deep water – Pelagic: the open ocean Marine Habitats • The majority of marine ecosystems are Benthic, but there are also a few found in the Pelagic habitat – Coral Reef – Tide Pool – Salt Marsh – Mangrove Forest – Deep Ocean – Kelp Forest Human Impact on the Ocean • The ocean is used in much the same way as is the lithosphere • Transportation, Resource Extraction (both biotic and abiotic), Tourism etc. are all ways in which people use oceans • As a result of the above-mentioned ocean usage, pollution and overexploitation occurs Pollution and Overexploitation • Pollution – any unwanted substance that is released into the ocean as a result of resource extraction, transportation, or tourism • Overexploitation – is the taking of too many individuals of a marine species thereby making it impossible for those remaining to replenish the numbers lost through fishing • Bycatch – non target marine species are killed as a result of becoming entangled in nets meant to catch another marine species Examples of Pollution & Overexploitation • http://www.upi.com/Top_News/International /2010/02/14/Canada-to-close-ports-due-toover-fishing/UPI-74111266192280/ • http://marineconservation.suite101.com/article.cfm/what_i s_bycatch • http://www.buzzle.com/articles/oceanpollution-causes.html MPA’s & MR’s • Marine Protected Area (MPA): Geographic area with discrete boundaries that has been designated to enhance the conservation of marine resources. This includes MPA-wide restrictions on some activities such as oil and gas mining and the use of zones such as fishery and ecological reserves to provide higher levels of protection. • Marine Reserve: A zone in which some or all of the biological resources are protected from removal or disturbance; encompasses both fishery and ecological reserves.