← Oceanography Ch. 11 Export Options Alphabetize Word-Def Delimiter Tab Comma Custom Def-Word Delimiter New Line Semicolon Custom Data Copy and paste the text below. It is read-only. Select All Territorial Sea The distance that could be protected by cannons out to shore, which determined which nation owned what. Every country controlled a coastline maintained ownership of a three mile territorial sea. United Nations Conference on the Law of the Sea Held in 1958 in Geneva. Established that mining of minerals and prospecting of minerals on the continental shelf was under the control of the country that owned the nearest land. Since the continental shelf is under interpretation, it led to disputes. Coastal Nations Jurisdictions Exclusive economic zone established for coastal nations. Originally 200 miles, if the continental shelf extends past that, then the EEZ is extended to 350 miles. Free Passage Free Passage for all ships is preserved. Deep Ocean Mineral Resources Puts private mining under control the International Seabed Authority. Companies must fund two operations, one for them, and one controlled by the ISA. Reason for industrialized nations opposing it. Still very contentious. Arbitration of Disputes A United Nations tribunal will adjudicate disputes. Coastal Water Shallow water areas that adjoin continents or islands. If the continental shelf is broad and shallow, coastal waters can extend several kilomters from land. If it has significant reliefs and drops, it can occupy a relatively narrow band. Halocline When freshwater mixes with seawater, it forms a wedge at the ocean, creating a _____. Isohaline When water is shallow enough, tidal mixing causes the freshwater to mix with the seawater, reducing the salinity of the water column. Freshwater runoff generally decreases the salinity of sea water. Where precipitation on land is mostly rain, the runoff peaks during the rainy season. Where runoff is mainly due to melting snow and ice, it peaks during the summer. When dry wind goes across the sea, it increases evaporation, creating a halocline. Isothermal In both low and high latitude conditions, this occurs. Surface temperatures are generally hot. High altitude conditions usually indicate sea ice. Thermocline Layer of rapidly changing temperature. May develop from surface water being warmed during the summer and cooled during the winter. Coastal Geostrophic Currents Wind and runoff currents create _____ currents in ocean waters. In the Northern Hemisphere, the currents go northward in western coasts, and southward in eastern coasts. It goes opposite in the Southern Hemisphere. High volumes of freshwater creates wedge of water that slopes away from the shore. Creates flow of low salinity water towards the open ocean. Variable because they depend on the amount of water runoff and the wind strength. If wind strength is high and water runoff is high, the current is high. Bounded by eastern or western boundary subtropical currents. Davidson Current Heavy precipitation combined with strong winds creates to produce a strong northward flowing current, between the shore and the California current. Estuary Partially enclosed coastal body of water in which freshwater runoff dilutes salty ocean water. Most common feature is river mouth. Exhibit large variations in temperature and salinity. Mouth of large rivers form the most economically significant estuaries because they are seaports and ports. Coastal Plain estuary Forms as sea level rises and floods existing river valleys. Estuaries exist because sea level has risen since continental glaciers started melting. Also called drowned river valleys. Fjord Forms as sea level rises and floods a glaciated valley. Water carved valleys have v shaped valleys, while ____ are U shaped valleys with steep walls. A shallowly submerged mass of glacial deposit, called a moraine, is located near the ocean entrance. Bar built estuary Shallow and separated from the open ocean by sand bars that are deposited parallel to the coast by wave action. Lagoons that separate barrier islands from the mainland are ______. Tectonic Estuary Forms from faulting and folding of rocks creates creates a restricted down dropping area into which rivers flow. Mixing of Water in Estuaries Freshwater runoff moves across the upper layer of the estuary towards the open ocean, whereas denser seawater moves in a layer just below the head of the estuary. Vertically mixed estuaries Shallow, low volume estuary where net flow flows from the head of the estuary towards it's mouth. Salinity at any point in the estuary is uniform from top to bottom because river water mixes evenly with ocean water at all depths. Salinity lines curve at the edge of the estuary because of the Coriolis effect. Slightly stratified estuary A somewhat deeper estuary in which salinity increases from the head to the mouth at any depth. Two layers of water. One is less saline, less dense upper water from the river, and the other is the more saline, more dense upper water from the ocean. Separated by a zone of mixing. Estuarine circulation pattern Circulation in slightly stratified estuary is a net surface flow of low salinity water toward the ocean and a net subsurface flow of seawater toward the head of the estuary. Highly stratified estuary Deep estuary in which upper layer salinity increases from head to mouth, reaching a value close to that of open ocean water. Deep water layer has a uniform open ocean salinity at any depth throughout the estuary. An estuarine circulation is well developed in this estuary. Mixing at the interface of the upper water and the lower water creates a net movement from the deep water mass into the upper water. Less saline surface water moves from the head into the mouth, growing more saline as the water from the deep mass mixes with it. Strong haloclines develop at the contact between the upper and lower water masses. Salt Wedge Estuary An estuary in which a wedge of salty water extends from the ocean beneath the river water. Typical of the mouths of deep, high volume rivers. No horizontal salinity gradient exists at the surface because surface water is fresh throughout the estuary. Anoxic Waters without oxygen. In Chesapeake Bay a strong halocline and pynocline develop, preventing the fresher surface water and saltier deep water from mixing, creating this. Lagoons Landward of barrier islands lie protected, shallow bodies of water. Three zones: 1) Freshwater zone that lies near the head of the lagoon where rivers enter. 2) Transitional zone of brackish water that occurs near the middle of the lagoon. 3) Saltwater zone that lies close to the lagoon's mouth. Summer increases salinity. Rainy seasons increase them. Tidal effects are greatest near the entrance to the lagoon. Marginal seas At the margins of the ocean are relatively large semi-isolated bodies of water. Most of these seas are created from tectonic events that have isolated low lying pieces of ocean crust, or behind volcanic arcs. These waters are shallower than and have varying degrees of exchange with the open sea. Mediterranean Sea Number of small seas connected by narrow necks of water into one larger sea. Remnant of the Tethys Sea, and is one of the few inlaid seas in the world underlain by oceanic crust. Has a very unique circulation pattern. Caused by the dry, intense heat pattens Sill Underwater ridge that separates the Mediterranean sea into two major basins. Mediterranean Circulation Circulation between the Mediterranean Sea and the Atlantic Ocean is typical of closed, restricted basins where evaporation exceeds precipitation. The unusual circulation of the Mediterranean is caused by the dry, intense heat of the Middle East, where a huge volume of water evaporates from the eastern Med. and causes a huge inflow of Atlantic Ocean water to replace. The rest of the Atlantic Ocean that doesn't go into the Mediterranean sinks and becomes Mediterranean Intermediate Water. Evaporation of inflowing water from the open ocean increases the sea's salinity to very high values. This denser water eventually sinks and returns to the open ocean as subsurface flow. Evaporation exceeds input in the Mediterranean, whereas in most estuaries freshwater input exceeds water loss to evaporation. Wetlands Ecosystems in which the water table is close to the surface, so they are typically saturated most of the time. Can border either freshwater or coastal environments. Are some of the most productive ecosystems in the world. Salt marshes serve as nurseries to more than half of the world's commercial fishes. Also amazingly efficient at cleaning up polluted water. Can buffer coastal regions from flooding by absorbing excess water and protect shorelines from water. More than half of the nation's ______ have evaporated, due to removal for agricultural, housing, and industrial purposes. Compounded by a lack of fresh sediment from regular river floods. The soil in _____ compresses over time, a process called subsidence, which normally, the growth of plants and infusion of fresh sediment offset. With these factors eliminated, many wetlands are sinking into the ocean faster than they are building up. 50% of the world's wetlands have been destroyed over the past century. The Office of Wetlands Protection (OWP) , established by the EPA, tries to slow the loss of wetlands. A rise in sea level is predicted to exacerbate the loss of wetlands. Salt Marshes Support a variety of salt tolerant grasses and other low lying plants that are termed halophytic. Intermittently submerged by ocean water and has oxygen poor mud and accumulation of organic matter called peat deposits.Restricted to about 30 and 65 degrees latitude. Mangrove Swamps Support various species of mangrove trees. Retricted to tropical regions. Pollution The introduction by man, directly or indirectly, of substances and energy into the marine environment which cause harm. Environmental Bioassay One of the most widely used techniques for determining the concentration of pollutants that negatively affect living resources of the ocean. Shortcomings: Does not predict the long term effect of pollution, does not predict how pollutants may combine with other substances to create new types of pollutants, also time consuming and laborious. Petroleum Spills The result of shipping accidents, such as the Exxon Valdez spill in 1989. Only the 53rd most damaging spill; the most destructive was the result of the Iraqi army intentionally dumping oil into the Persian Gulf during their invasion of Kuwait. 47% of oil in the ocean is caused by natural oil seeps, while 53% is caused by humans. Hydrocarbons Oil is composed of the elements hydrogen and carbon. Are organic substances, so they can be broken down and biodegraded by microorganisms. Because of this, many pollution experts believe oil to be among the least damaging substances introduced into the ocean. When oil is combined with other elements, and is combined with the other complex elements of the ocean, the effects can be disastrous for organisms, killing them outright. Concern over the long term effect of oil spills. Toxic Compounds Bad stuff. Bio remediation Using microorganisms such as bacteria and fungi that naturally biodegrade oil to aid clean up. Releasing bacteria directly into the environment is one form of _____ bio remediation. Another method is providing conditions that stimulate growth of naturally occurring oil-degrading bacteria. Preventing oil spills: Double hulled ships are mandated, and in one case, authorities burned a ship in order to reduce the amount of oil that would be released into the ocean. Sewage sludge Semi solid material that remains after primary and secondary treatment. Contains a toxic brew of human waste and other chemicals. Primary treatment Process whereby sewage sludge is allowed to settle and dewater. Secondary treatment Process whereby sewage sludge is exposed to bacteria killing chlorine. DDT Pesticide. Persistent, biologically active chemical that has been introduced into the oceans entirely as a result of human activities. Because of it's persistence, toxicity, long life, and propensity for being accumulated in food chains, it has been classified as a Persistent Organic Pollutant (POP). Widely used in agriculture in the 50s and improved crop production. It's extreme effectiveness in killing insects and it's persistence as a toxin in environments have resulted in many environmental problems, including disrupting marine food chains. It's use is banned in the U.S, but U.S companies still produce _____ and sell it to other countries. Causes birds to have very thin eggshells. Lingers in the environment, and is transported via the atmosphere and river runoff. PCBs Pesticide. Persistent, biologically active chemical that has been introduced into the oceans entirely as a result of human activities. Because of it's persistence, toxicity, long life, and propensity for being accumulated in food chains, it has been classified as a Persistent Organic Pollutant (POP). Industrial chemicals that were once widely used as a liquid coolant and insulation in industrial equipment. It causes liver cancer and harmful genetic mutations in animals, as well as affecting animal reproduction. Mercury A silvery liquid at room temperature, has many industrial uses. When it enters the ecosystem, it forms an organic compound that is generally toxic to most living things. Three variables were considered in order to determine a safe level of mercury in fish. 1) The rate at which each group of people consumed fish. 2) The mercury concentration in the fish consumed by that population. 3) The minimum ingestion rate of mercury that induces disease symptoms. The maximum concentration of mercury in fish in the that people can be consumed by people is 2.0 ppm. The FDA doubled this concentration to 1.0 ppm, which adequately protected every person in the U.S. Minamata disease Mercury poisoning due to a chemical plant built in Japan's Minamata bay. Became epidemic in 1956. Causes sensory disturbances including blindness and tremors. Bioaccumulation Certain marine organisms concentrate within their tissues many substances found in minute concentrations in seawater. Biomagnification When animals eat other animals, some of these substances, including toxic chemicals, these substances move up the food chains and become concentrated in the tissues of larger animals. Non-point source pollution Also called poison runoff. Any type of pollution entering the ocean from multiple sources rather than from a single discrete source, point or location. In most urban areas, _____ arrives at the ocean via runoff from storm drains. Can be hard to difficult to pinpoint where it originates. Plastic Constitutes the vast majority of marine debris. About 80% of marine debris comes from land based sources. Floats and is not readily biodegradable. Marine birds have also ingested so much floating plastic that it fills their stomach and they die of starvation. Marine turtles eat the plastic because it looks similar to the plankton on which they feed. Floating plastic pieces have a high affinity for poisons, and they can gain poisons up to a million times their concentration. Only breaks down into smaller pieces, due to photodegrade, in which sunlight breaks ____ down. Eastern Pacific Garbage Patch About twice the size of Texas and is estimated to contain 91 million metric tons of debris. MARPOL Short for marine pollution. In 1988, the International Convention for the Prevention of Pollution from Ships proposed a treaty banning the disposal of all plastics and regulating the dumping of most other garbage at sea. By some measures, has reduced garbage, but in other areas, there is no improvement. A provision to MARPOL provides that nations have their own shore based facilities where ships can dispose their trash, but many developing countries can not provide these facilities. Non-native species Can wreak ecological havoc by dominating native species. Caulerpa taxifolia Native of tropical waters, is ideal in aquariums and grows quickly. When it is introduced into new habitats, it grows persistently and dominates the native marine life. Zebra mussels Invaded the Great Lakes region. Proliferated in the waters of Eastern Canada and the United States. Driven out native mussels, altered the ecology of freshwater lakes and streams, and blocked the water carrying pipes of power plants and other industrial facilities.