8th Grade Science Quick Review Dana Frank Danao.frank@cms.k12.nc.us

1. Draw a pie chart that represents the distribution of water on earth 1. Draw a pie chart that represents the distribution of water on earth. 2. Why is stewardship of our fresh water vital? Write as many reasons as possible

1. 97% salt 3% fresh Majority of fresh water in ice caps & glaciers Majority of accessible fresh water found in aquifers 2. Limited supply of fresh water Fresh water is not distributed equally on the planet or in the US Water systems are connected, Contaminated water in one area will end up in another Toxins in fresh water & salt water can accumulate in food & wild life

Describe how water moves in and out of an aquifer. How do human activities and climate conditions affect an aquifer?

3. Water moves in through recharge zone into aquifer Water out through wells Gravity moves water through the aquifer toward oceans or other major water source Increasing the withdrawal of water from an aquifer by homes and industry lowers the water table. Without recharge (rain), water supply is depleted. Extreme drought diminishes recharge and lowers water table Pollution that enters recharge zones (animal waste/farms, landfills, illegal dumping) makes its way to groundwater

Aquifers are large reservoirs of ground water Aquifers are large reservoirs of ground water. These can be accessed by wells, some natural springs bring water out of aquifers through the force of gravity. Water in an aquifer is usually cleaner than surface water, b/c it filters through rocks and sand (recharge area) on it’s way to the aquifer. The water table is the top of the water in an aquifer.

Describe how water moves across earth’s surface Describe how water moves across earth’s surface. Sketching a watershed may help in your description.

A watershed is the large area of land the drains waters into streams, that then feed into larger and larger rivers, until draining into a major river. Watersheds are bordered by divides…high areas of land (mtns) that separate one watershed from another http://www.youtube.com/watch?v=2KCBRPEs4g4

Summary 97% of earth’s water is in the oceans Of the remaining 3% fresh water…most is frozen in glaciers and polar ice caps The largest % of fresh water is groundwater… aquifers Fresh water moves across earth’s surface in watersheds/riverbasins

Water Quality Indicators The health of a water system is determined by the balance between physical, chemical, and biological variables. Physical variables include temperature, turbidity. Chemical variables include dissolved oxygen and other gases, pH, nitrates and phosphates. Both natural and man-made forces are constantly changing these variables. Biological variables are living organisms.

Describe: a) How each of the following indicators affects water quality. b) What may cause each to reach an unhealthy level? Temperature Turbidity Dissolved Oxygen pH Nitrates and Phosphates

Water Quality Indicator Notes Turbidity Description: Murkiness of water due to suspended particles Levels: Ideal = 1NTU High = 5 NTU+

Turbidity Causes: Erosion from construction urban run off disturbance of stream beds from bottom feeders/livestock increased algal growth septic system leaks decaying plant matter flooding

Turbidity Results: Increase temperature Decrease in DO Clogs gills in some aquatic organisms, smothers aquatic plants making photosynthesis difficult

Temperature Definition: Amount of kinetic energy Levels: Low: cannot be tolerated below 320F High: only rough fish can tolerate temperatures above 970F

Temperature Causes: Loss of shade from removal of vegetation Thermal Pollution: industry discharge seasonal temp changes Results: Decreased levels of DO increased bacterial levels increased algae growth

4. Thermal pollution from human activities Slide 11. Abiotic Factors-Temperature Water temperature is also influenced by human activity. This is North Anna Power Station, located northwest of Richmond. The cooling water from the reactor that is discharged back into Lake Anna is a few degrees warmer than the surrounding lake water. Temperature increases from human activities Photo: Dominion Virginia Power – North Anna Power Station

pH Description: How acidic is the water Levels: 07 is acidic 7 is neutral 714 is basic Surface Freshwater: 6.0 9.0

pH Cause: Acid rain minerals in soils Results: Death of sensitive bio-indicators Death or damage to plants

What is pH? 0-7 water is acidic 7 water is neutral 7-14 water is basic Slide 20. Abiotic Factors-pH pH is usually a number on a unitless scale, from 0 – 14. 0 being most acidic and 14 being most basic. A pH of 7 is considered neutral, with equal amounts of hydrogen and hydroxide ions. 0-7 water is acidic 7 water is neutral 7-14 water is basic

What is the optimum freshwater pH? Slide 21. Abiotic Factors-pH The pH of rain depends on the amount of industrialization in the rainfall area. Air pollution from emissions from industry often produce carbonic, sulfuric and nitric acids which lower the pH. The water which drains a limestone area high in bicarbonates can raise the pH of the water as high as 8.5. Aquatic organisms are VERY sensitive to changes in pH. Rainfall: 5 – 6.5 Most freshwater systems: 7 - 8 Most aquatic organisms: 6.5 – 8.2

Dissolved Oxygen Description: Oxygen gas dissolved in water O2 enters water through photosynthesis and churning water Levels: 4-5 ppm optimal to support life  

Dissolved Oxygen Cause: Increased Temp Decaying plant material Effect: Less diversity of bio-indicators fish-kills

Nitrates & Phosphates Description: Excess nutrients Level: Nitrates above 1 ppm Phosphates above .003 ppm

Nitrates & Phosphates Cause: Fertilizer run off Animal waste Leaking septic systems Manure pits (hog farms, etc) Clay soils (phosphates) Result: Eutrophication – overgrowth of algae (pond scum) Low DO

1995 Lagoon break at Cape Fear

Nitrates & Phosphates

What are bio-indicators and how are they used to determine water quality?

Bio-Indicators Description: Macro-invertebrates living in water that are sensitive to pollution Healthy Level: Large numbers and diversity

Bio-indicators are living organisms that require specific conditions in order to survive. Their presence in waters, or lack of presence, is an indicator of the health of a water system. They can be used as sentinels of a developing problem

What is eutrophication What is eutrophication? Describe the impact of human activity on eutrophication.

Bio-Indicators Cause: Increased levels of pollution Result: Less diversity of organisms Fewer organisms

EUTROPHICATION FLOW CHART Excess Nutrients  Algal Bloom (pond scum)  darkness below surface  photosynthesis stops  decomposers & other organisms use up oxygen  DEATH (gradual buildup of dying plant matter the pond becomes a meadow)

Identify each of the following as point source or nonpoint source pollution: 2. 3. 4. 5. 6. Runoff

Stewardship implies that we are caretakers of our water for future generations. The EPA established the Clean Water Act to ensure oversight and testing of surface waters

Label the following ocean regions What variables are used to create these regions?

Label the following ocean regions What variables are used to create these regions? Ocean regions are determined by temperature and light penetration Intertidal Neritic Open ocean Deep ocean

Ocean Region Properties Adaptations of species that live there Intertidal Neritic Open Ocean Deep Ocean

1. Intertidal Shallowest area Between the low and high tide lines Changing environment

Each tiny barnacle is enclosed in grayish-colored shells that can completely close. Once they begin life on the rock, they cannot relocate as these shells are attached permanently to their substrate. When dead, the outside shell remains as an empty volcano until it degrades They have an incredible reproductive style. They are what we call hermaphroditic in biology … that is they are both male and female in the same body. Each animal makes both eggs and sperm, but usually cannot get its sperm to its own eggs. Barnacles have an inflatable penis that is used in mating with a neighbor. This penis can inflate and extend up to 2 inches from the tiny barnacle. Buckshot Barnacles

2. Neritic Zone Always underwater On continental shelf Coral reef…diversity & nutrients

Phytoplankton =ocean producers Zooplankton eat phytoplankton Primary producers are organisms that convert inorganic carbon in carbon dioxide into organic carbon by autotrophs. There are two types of primary producers. They are phytoplankton, or autotrophic producers, and zooplankton, or heterotrophic producers. The neritic zone contains largely diatoms and dinoflagellate species. There are many primary producers in the neritic zone.

Sponge with brittle star Coral

Oceanic Zones Open Ocean Surface – 200 meters Sunlight, warm Less plentiful nutrients

Deep Zone - starts at continental slope and extends to 4000 m Brittle Stars - starts at continental slope and extends to 4000 m - little or no sunlight - cold 4°C - very high pressure

Ogrefish Deep Sea Angler Coelacanth

How does water move through the ocean? Water moves through the ocean, driven by currents. Surface currents are caused by waves, deep currents are caused by differences in density.

Nutrients move up from the ocean floor through upwelling. http://www.youtube.com/watch?v=APMzM-xYlOs How do climate patterns affect upwelling?

How do climate patterns affect upwelling? Change in climate pattern affects ocean surface temperatures. These alter wind patterns which are responsible of the location and strength of upwelling.

Describe the importance of estuaries to the environment.