CHEMICAL and PHYSICAL FEATURES CHAPTER 1 MARINE BIOLOGY

The Nature of Water A water molecule is made up of one oxygen and two smaller hydrogen atoms. A water molecule is made up of one oxygen and two smaller hydrogen atoms. Water molecules are held together by hydrogen bonds. Water molecules are held together by hydrogen bonds.

Water strider

Water can exist in three different states: Solid, Liquid or Gas Water can exist in three different states: Solid, Liquid or Gas The temp. will determine the state. The temp. will determine the state.

When the temp. goes up, the liquid water turns into a vapor phase – Evaporation When the temp. goes up, the liquid water turns into a vapor phase – Evaporation As liquid water cools, it becomes denser and sinks in the water column. As liquid water cools, it becomes denser and sinks in the water column. Density =mass/volume Density =mass/volume

Heat and Water It takes a large amount of energy (heat) to change the state of water. It takes a large amount of energy (heat) to change the state of water. Latent heat of melting = the amount of heat needed to melt a substance. Latent heat of melting = the amount of heat needed to melt a substance. Water has a very high latent heat. Water has a very high latent heat. Heat capacity = how much heat a substance can store. Heat capacity = how much heat a substance can store. Water has one of the highest heat cap. Water has one of the highest heat cap.

Water can also absorb a lot heat when it evaporates. Water can also absorb a lot heat when it evaporates. Latent heat of evaporation. Latent heat of evaporation. These unique properties are a result of the hydrogen bonds. These unique properties are a result of the hydrogen bonds. (demo) (demo)

Water as a Solvent Water is known as the universal solvent Water is known as the universal solvent It does a very good job of dissolving Salts It does a very good job of dissolving Salts The ionic bond between Na and Cl becomes weak in water because the ion is surrounded by a water molecule which insulates the charges ( think about a wire in your house) The ionic bond between Na and Cl becomes weak in water because the ion is surrounded by a water molecule which insulates the charges ( think about a wire in your house)

Seawater The salts came from weathering and hydrothermal vents. The salts came from weathering and hydrothermal vents.

The amount of salts in the seawater is called Salinity The amount of salts in the seawater is called Salinity We measure this in parts per thousand or PPT. We measure this in parts per thousand or PPT. The avr. Ocean salinty is 35 ppt. The avr. Ocean salinty is 35 ppt. Salinity in L.I.S. =10-20 ppt. Salinity in L.I.S. =10-20 ppt. We may only see 1-5 pp. Why? We may only see 1-5 pp. Why? The instrument we use is called a salinometer The instrument we use is called a salinometer

We can also collect this data at various depths with the use of sampling bottles (Niskin Bottles) We can also collect this data at various depths with the use of sampling bottles (Niskin Bottles)

Dissolved gasses Oxygen, carbon dioxide and nitrogen are found in the oceans Oxygen, carbon dioxide and nitrogen are found in the oceans The one we are most concern with oxygen The one we are most concern with oxygen A good level would be 5 ppm. A good level would be 5 ppm.

Hypoxia When D.O. is consumed faster than it is supplied. When D.O. is consumed faster than it is supplied. In the summer we are prone to low levels do to calm water and the solubility of oxygen is lower at higher temps. In the summer we are prone to low levels do to calm water and the solubility of oxygen is lower at higher temps. l l l l

Transparency Sunlight needs to penetrate the water for photosynthesis to occur Sunlight needs to penetrate the water for photosynthesis to occur To measure this we use a Secchi disk To measure this we use a Secchi disk

Water Density At sea level the pressure is 1 atmosphere =14.7 pounds per square inch (psi) At sea level the pressure is 1 atmosphere =14.7 pounds per square inch (psi) Every 10 meters you increase by one atmosphere Every 10 meters you increase by one atmosphere To adjust to the depth organisms use swim bladders and the production of oils To adjust to the depth organisms use swim bladders and the production of oils If organisms with gas filled structures may be injured when brought up to fast or from great depths. If organisms with gas filled structures may be injured when brought up to fast or from great depths.

Put It All Together

Wind and Currents Winds are caused by heat energy of the sun Winds are caused by heat energy of the sun

The Coriolis Effect- since the earth is rotating air moving over the surface tends to turn. The Coriolis Effect- since the earth is rotating air moving over the surface tends to turn.

Currents Wind drives surface currents Wind drives surface currents

Waves Wind causes waves Wind causes waves

Fetch- The distance over open water which the wind blows to form waves Fetch- The distance over open water which the wind blows to form waves What is our fetch ? What is our fetch ?

Swells Swells Surf zone Surf zone Breakers Breakers

Tides The periodic rise and fall of the level of the ocean The periodic rise and fall of the level of the ocean Caused by the gravitational pull of the sun and moon as well as the centrifugal force Caused by the gravitational pull of the sun and moon as well as the centrifugal force

It takes the moon 24 hours and 50 min. to circle the earth = full tidal cycle It takes the moon 24 hours and 50 min. to circle the earth = full tidal cycle

We have two high tides and two low tides every 24hrs. And 50 mins. We have two high tides and two low tides every 24hrs. And 50 mins. This is called semidiurnal tides This is called semidiurnal tides ne.com/displayPredictio ns.do?locationInfo= South+Norwalk- 6&month=2&day=8&ye ar= ne.com/displayPredictio ns.do?locationInfo= South+Norwalk- 6&month=2&day=8&ye ar= ne.com/displayPredictio ns.do?locationInfo= South+Norwalk- 6&month=2&day=8&ye ar= ne.com/displayPredictio ns.do?locationInfo= South+Norwalk- 6&month=2&day=8&ye ar=2008

When you only have one per day it is diurnal When you only have one per day it is diurnal Usually very large tidal range (distance between high and low) Usually very large tidal range (distance between high and low) Bay of fundy = 50 ft + Bay of fundy = 50 ft + Norwalk 6-7 ft. Norwalk 6-7 ft.

Some places have tides that dont follow a pattern Some places have tides that dont follow a pattern

When the moon and sun line up we get the largest tidal range When the moon and sun line up we get the largest tidal range Full moon Full moon New moon New moon Quarters Quarters Spring tide Spring tide Neap tide Neap tide

Can We Predict Tides? We use tide tables We use tide tables Since we have semidiurnal tides we can Divide the 24hrs.+50 min. into four time blocks each 6 hrs.+12 min. Since we have semidiurnal tides we can Divide the 24hrs.+50 min. into four time blocks each 6 hrs.+12 min. If high tide was at 12 noon low would be at 6:12 am If high tide was at 12 noon low would be at 6:12 am When would the next high tide be? When would the next high tide be?

How Animals Use Tides Horseshoe crab Horseshoe crab Coffeebean snail Coffeebean snail Sea turtles Sea turtles

Coffee Bean Snail

End of Chapter 3