G S Powell and S Deperno 8 th

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G. S. Powell and S. Deperno 8 th Grade Science East Cary Middle School

G. S. Powell and S. Deperno 8 th Grade Science East Cary Middle School 2013

Importance of Oceans � Remove carbon dioxide from the atmosphere and stores it. �

Importance of Oceans � Remove carbon dioxide from the atmosphere and stores it. � Provide oxygen to the atmosphere. � Are home to many species of animals and plants and many complex food webs. � Provide food for the human population. � Used for travel and shipping. � Drilled for oil. � Mined for minerals. � Recreation.

Why is the Ocean Salty? � Salts slowly erode from the Earth’s crust and

Why is the Ocean Salty? � Salts slowly erode from the Earth’s crust and are carried down rivers into the oceans. � Solids and gases from underwater volcanoes dissolve in the sea. � Hydrothermal vents on ocean floors bring super heated water with many dissolved minerals back into the sea.

Why is the Ocean Salty? � The average salinity of seawater is 35 parts

Why is the Ocean Salty? � The average salinity of seawater is 35 parts per thousand (ppt). � Evaporation and freezing sea ice increases salinity. � Rainfall, run-off from land melting sea ice decreases salinity. � Salinity is lower in coastal waters, polar seas and near the mouths of large rivers.

Dissolved Gases in the Ocean � Cold water holds more gas then warm water.

Dissolved Gases in the Ocean � Cold water holds more gas then warm water. � Lower salinity water holds more gases then higher salinity water. � Deep water holds more gas then shallow water.

Dissolved Gases in the Ocean � Waves at the ocean surface release gases from

Dissolved Gases in the Ocean � Waves at the ocean surface release gases from the water into the air. � Phytoplankton use CO 2 to photosynthesize and release O 2 into the water. � The O 2 is used by ocean animals.

Carbon Dioxide and the Ocean � H 2 O reacts with CO 2 and

Carbon Dioxide and the Ocean � H 2 O reacts with CO 2 and creates compounds animals use to make shells (carbonic acid and bicarbonates). � This traps CO 2 in the ocean. � Coral and shell fish use these chemicals to make their skeletons and shells. � Ocean acidification: As atmospheric CO 2 rises, CO 2 rises in the ocean, causing ocean water p. H to drop. � Ocean acidification is a threat to many species.

Oceans and World Climate � The oceans are an important part of the world’s

Oceans and World Climate � The oceans are an important part of the world’s climate because they collect, mix and store water, heat and carbon dioxide. � The oceans are the largest reservoir (a place where something is stored) of heat and water on Earth’s surface. � The oceans hold and circulate more water, heat and carbon dioxide than the atmosphere. � The ocean and atmosphere form weather patterns such as: El Nino

El Nino � An abnormal climate event occurring every 2 to 7 yrs in

El Nino � An abnormal climate event occurring every 2 to 7 yrs in the Pacific Ocean. � Due to unusual patterns of winds in the West Pacific ( a vast sheet of warm water moves toward South America) � Can last 1 to 2 yrs � Prevents upwellings, so fish and birds die � Affects the climate in North and South America

Oceans and Climate � Sea water has a high density and specific heat so

Oceans and Climate � Sea water has a high density and specific heat so it stores and later releases a lot of heat energy from its surface layers. � This causes milder climates near the ocean, (warmer winters, cooler summers). � The ocean controls the amount of radiation released into ecosystems. � Evaporation cools surface water and the air above it. (Especially near the equator)

Oceans and Temperature � Heat stored in the ocean can affect climate even a

Oceans and Temperature � Heat stored in the ocean can affect climate even a year later. � Air temperatures all over the world are regulated by the circulation of heat in the ocean. � Ocean currents distribute energy, nutrients and ocean life.

Ocean Currents � Currents circulate energy, nutrients and ocean life.

Ocean Currents � Currents circulate energy, nutrients and ocean life.

Surface Currents � Wind creates surface currents in the ocean. � Are several hundred

Surface Currents � Wind creates surface currents in the ocean. � Are several hundred meters deep � Move in circular patterns � As Earth rotates the paths of the winds and currents curve in relation to Earth’s surface. � Gulf Stream – the largest surface current in the North Atlantic

How Surface Currents Affect Climate � Climate – the pattern of temperature and precipitation

How Surface Currents Affect Climate � Climate – the pattern of temperature and precipitation typical of an area over time. � Surface currents warm or cool the air above them, influencing the climate of the land near the coast � Carry warm water from the tropics toward the poles and cold water from the poles towards the tropics � Winds pick up moisture from warm currents � Winds are cooled by cold currents so the winds bring cool dry weather.

Deep Currents � Are caused by differences in density in the ocean water. �

Deep Currents � Are caused by differences in density in the ocean water. � Density is determined by temperature and salinity. � At the North and South Poles, water cools and ice forms. The salt concentration in the remaining water increases making it more dense; the saltier, denser water sinks creating deep ocean currents. � Flow more slowly than surface currents

Upwellings � Winds move warm surface water offshore and cold water from the bottom

Upwellings � Winds move warm surface water offshore and cold water from the bottom rises to fill the void. � Nutrients and minerals from the bottom are brought to the surface. � Minerals: required by organisms in their diet; stored in ocean floor sediment � Phytoplankton use these nutrients to grow. � Consumers eat the phytoplankton. � Home to huge schools of fish �Pacific Ocean – West Coast of South America – Chileanchovies �South Africa

Upwelling and Biodiversity

Upwelling and Biodiversity

Estuaries � Where rivers meet the ocean. � Partly closed coastal waters where fresh

Estuaries � Where rivers meet the ocean. � Partly closed coastal waters where fresh and salt water mix creating less salty water called brackish water. � Trap nutrients and sediments from land ocean tides. � Generally shallow so sunlight penetrates to the bottom = plant growth. � Pamlico Sound, Albemarle � Sound, Back Sound are a � few of the estuaries in NC.

Importance of Estuaries � Are the nursery grounds to the oceans!!!!! � No salt

Importance of Estuaries � Are the nursery grounds to the oceans!!!!! � No salt marshes – no seafood!!! � Provide protected areas for young sea animals to grow. � Estuaries are one of the most productive ecosystems on Earth. � Great bio-diversity (lots of different plants and animals. � Filter pollutants, chemicals and pathogens. � One oyster can filter 25 gallons of water/day.

Pamlico Sound � The largest estuary in NC � Water from Northeastern NC and

Pamlico Sound � The largest estuary in NC � Water from Northeastern NC and Southeastern VA drains into the Pamlico � Our Neuse River Basin drains into the Pamlico � Late summer fish kills are common in the mouth of the Neuse River/Pamlico Sound Estuary due to excess nutrients that stimulate algal and bacterial growth (Eutrophication – low dissolved oxygen)

Importance of Estuaries � � Bacteria eat organic matter in marsh sediments and release

Importance of Estuaries � � Bacteria eat organic matter in marsh sediments and release carbon dioxide, hydrogen sulfate, and methane giving the marsh its characteristic rotten egg odor Benthic = bottom dwellers; ocean floor

Estuary Ecosystems � Salt Marshes � Common in temperate regions throughout the world; �

Estuary Ecosystems � Salt Marshes � Common in temperate regions throughout the world; � Salt marsh grasses such as Spartina are common � Mangrove Forests � Common in warmer waters such as South Florida and equatorial regions � Mangrove trees are common

Threats to Estuaries � Chemicals washed from land end up in rivers that feed

Threats to Estuaries � Chemicals washed from land end up in rivers that feed into estuaries. � Toxins can accumulate in sediments and animals. � Leaking septic tanks can make shell fish hazardous to eat.

Marine Ecosystems � Ecosystem: living organisms and the non living components of their environment

Marine Ecosystems � Ecosystem: living organisms and the non living components of their environment interacting as a system. ◦ Shore Ecosystem: Intertidal zone (between high and low tide lines); along the edge of the ocean ◦ Ocean Ecosystem: Neritic Zone (over continental slope) and Oceanic Zones. ◦ Deep Ocean Ecosystem: >500 M deep; under Oceanic Zones

Ocean Zones: Vertical Zonation Patterns � Photic Zone – surface layers where light penetrates;

Ocean Zones: Vertical Zonation Patterns � Photic Zone – surface layers where light penetrates; ◦ Photosynthesis occurs here; most ocean organisms exist here ◦ Phytoplankton need sunlight and nutrients to survive. � Aphotic Zone – dark, cold, tremendous pressure; Includes Deep Ocean Ecosystems. ◦ Animals are specially adapted to survive: ex: bioluminescense –animals produce light through a chemical reaction extremophiles: organisms that thrive in extreme conditions

Ocean Organisms � Plankton – carried by currents and waves; � Nekton – free

Ocean Organisms � Plankton – carried by currents and waves; � Nekton – free swimmers � Benthos dwellers – bottom

Examples of Plankton and Benthos � Bottom Plankton: free floating; usually very small Benthos:

Examples of Plankton and Benthos � Bottom Plankton: free floating; usually very small Benthos: bottom dwellers

Food Chains and Food Webs � Marine ecosystems have tremendous biodiversity Examples of diverse

Food Chains and Food Webs � Marine ecosystems have tremendous biodiversity Examples of diverse marine ecosystems: estuaries, lagoons, coral reefs, kelp forests, open ocean � Many individual food chains overlap to form food webs in all these ecosystems. � Ocean food chains can intersect with land food chains when land animals feed on ocean animals or plants. ◦ Examples: humans, shore birds, seals, polar bears, sea otters, penguins

Simple Ocean Food Chain � Producers: � Phytoplankton � Consumers: All other organisms �

Simple Ocean Food Chain � Producers: � Phytoplankton � Consumers: All other organisms � Many food chains form a food web � Land ocean food webs are linked

Ocean Life � Phytoplankton are an important food source in the ocean. � Food

Ocean Life � Phytoplankton are an important food source in the ocean. � Food webs show ocean organisms are connected.

Deep Ocean Ecosystem: Hydrothermal Vents � Chemosynthesis: Bacteria convert sulfur and methane gases to

Deep Ocean Ecosystem: Hydrothermal Vents � Chemosynthesis: Bacteria convert sulfur and methane gases to food � Bacteria live in tube worms who they supply with food � Clams filter the water � Shrimp eat bacteria � Fish eat shrimp Heat from Volcanic Activity Water Temp. >400 o. C Extremophiles!!

Ocean Resources � Biotic – food, biomedical organisms ◦ Fish: 16% of total world

Ocean Resources � Biotic – food, biomedical organisms ◦ Fish: 16% of total world protein for human population ◦ Seafood species are rapidly declining in numbers. ◦ We are overfishing the worlds oceans! � Mineral – diamonds, gold, manganese nodules ◦ Dredging the ocean floor for minerals destroys plant and animal life � Tourism – 200 million jobs worldwide ◦ Leads to pollution of coastal ecosystems ◦ Ecotourism – favors low impact tourism

Energy Resources from the Ocean � Oil and Natural Gas – drill exploratory wells;

Energy Resources from the Ocean � Oil and Natural Gas – drill exploratory wells; requires government permits; permanent rigs are put in place for production; ◦ Has many impacts on the environment: rigs impact sea life; drilling affects the ocean and sea life; accidental spills occur and can be disastrous � Wind – NC has best potential sites on the East coast; two sites off Wilmington; one off Outer Banks � Conservation - of energy resources should be a critical part of our energy plan to minimize damage to the environment

Ocean Exploration � Ships: ◦ ◦ Sonar – determines ocean depth via sound waves

Ocean Exploration � Ships: ◦ ◦ Sonar – determines ocean depth via sound waves Drop floats and drifters into the currents Collect water samples Collect marine life ◦ ◦ view and collect samples of ocean floor and ocean life designed to withstand tremendous pressures Remote controlled or human occupied Robots � Submersibles � Satellite – Technology – ◦ Photographs, ocean temperatures; ocean color; phytoplankton,

Many of the images used were taken from: � http: //www. ck 12. org/book/CK-12

Many of the images used were taken from: � http: //www. ck 12. org/book/CK-12 -Earth- Science-For-Middle. School/r 5/section/14. 0/MSEarth%25 E 2%2580%2599 s-Atmosphere%253 Arev%253 A-1%253 Aof%253 A-Earth-Science. For-Middle-School/