Review and New Material Now that our class has tested… its times to move on BUT…. before we do one last review
The World’s Oceans 71% of the Earth’s surface is covered by ocean water. The oceans contain 97% of the earth’s water. All the oceans and seas are actually one continuous body of water.
Oceans The oceans are the Atlantic, Pacific, Indian, Arctic. The Pacific Ocean is the largest ocean. The area and volume of the Pacific Ocean are greater than the Atlantic and Indian combined.
Water Cycle The sun’s rays heat the surface of the ocean. The heat causes the water to evaporate. The evaporating water (clean, fresh water) enters the atmosphere as water vapor. The salt remains behind.
Water Cycle Winds carry water vapor over land. Some of the water vapor condenses to form clouds. The water in the clouds falls as precipitation.
Water Cycle Some of this water runs into rivers and streams which flow back into the oceans. Some of the water seeps into the soil and rocks become part of the groundwater.
Properties of Ocean Water Ocean water is a mixture of gases and solids dissolved in pure water. Oceanographers believe oceans contain all the natural elements on Earth. 85 of 90 have been found in the ocean.
Major Elements in the Ocean Ocean water is 96% pure water. Chlorine (1.9) and sodium (1.1) make up the next largest concentration of elements. Sodium chloride is table salt.
Sources of Salt in the Ocean When volcanoes erupt, rock materials and gases, such as chlorine, spew forth. As rivers, streams and glaciers move over rock and soil, they dissolve salts, such as magnesium, sodium and potassium, in them. As waves pound the shoreline, they dissolve salts from the rocks.
Salinity Levels The salinity is lower in areas where freshwater rivers run into the ocean. Salinity levels are also affected by animals such as clams and oysters that use calcium salts to build their shells. They remove salt from the water. In warm ocean areas where there is little rainfall and much evaporation, the amount of dissolved salts is much greater. In polar regions, the salinity levels are high because temperatures are cold enough for ocean water to freeze. Pure water is removed and salts are left behind.
Gases in Ocean Water The most abundant gases in ocean water are nitrogen, carbon dioxide and oxygen. The amounts of these elements vary with depth. They are more abundant at the ocean’s surface where sunlight causes more plant life.
Temperature of Ocean Water Warm water holds less dissolved gas than cold water. When ocean water is cold, like in polar regions, it sinks and carries oxygen rich water to the ocean depths. As a result, fish and other animals can live in deep parts of the ocean.
Edges of the Continents The shoreline is a boundary between where the land and the ocean meet. The area where the underwater edge meets of a continent meets the ocean floor is called a continental margin.
Essential Questions How does Climate and Ocean temperature affect Marine life? What do different Ocean animals need to survive? How do plants and animals adapt to their environments? How does exposure to tides affect life forms?
Ocean Life Zones Intertidal Zone (Splash Zone) Neritic Zone (Continental Shelf) Open Sea Zone – Bathyal (Continental Slope) Abyssal (Ocean floor)
Ocean Life Zones The plant and animal life in the ocean is affected by several factors. One factor is the amount of sunlight that penetrates the ocean. Another factor is the temperature of the ocean water. Water pressure is also a factor.
Major Groups of Ocean Life Plants and animals in the ocean are classified into three major groups based on their habits and the depth of the water in which they live. The three major groups are plankton, nekton and benthos.
Under the Sea What’s Up ? Hi There YO YO YO!!!
Plankton Plankton float at or near the surface where sunlight can penetrate. Most of the plankton are very small, such as algae. These organisms drift with the currents or tides. Plankton are the main food for many larger organisms. They account for most of the organisms in the ocean.
Nekton Whales, seals, dolphins, squid octopuses, barracuda and other fish are all nekton. Nekton are free-swimming organisms that feed on other nekton as well as on plankton. Many have adaptations enabling them to function at depths that have great pressure and no light.
Benthos Organisms that live on the ocean floor are benthos. The forms of these animals include crustaceans and shell fish. The deep bottom environments are sparsely populated with benthos. Some benthos are plants that live on the ocean floor in shallow waters where sun can penetrate.
Ocean Life Zones The classification of the ocean into life zones is based on the conditions in the ocean. These conditions vary widely. The classification includes the intertidal zone, the neritic zone and open-ocean zones.
Intertidal (Splash) Zone This region is the most changeable in the ocean. Anemones, crabs, clams, mussels and plants such as seaweed live here. They must be able to exist without water for periods of time. They must be able to anchor to keep from being washed out to sea.
Neritic ( Shelf) Zone This zone extends to a depth of 200 meters and receives plenty of sunlight. The water pressure is low and the temperature is constant. This zone can support plankton, nekton and benthos. Marine life is most abundant here.