Water

• H2O, Sea Water and what it means to life in the ocean….

Figure 3.01Hydrogen Bonds,Between water moleculesAre weak, butIMPORTANT!

States of water

• Water occurs as solid, liquid & gas naturally

• No hydrogen bonds in water vapor

• Some molecules joined by hydrogen bonds in liquid – bonds break & reform

• All molecules rigidly bonded in solid

Figure 3.02

Heat and Water

• Adding heat makes molecules vibrate

• Heat energy is used to cause vibration AND to break hydrogen bonds

Heat and Water

• Ice melts at relatively high temperatures compared to similar substances – (OoC instead of –90oC)

Water = Universal Solvent

• Good at dissolving salts (the solutes)

• Salts exist as separate ions in seawater

• Remember: Solvent dissolves, solutes are what gets dissolved!

Seawater

• Salts come from weathering of rock or outgassing from hydrothermal vents

• Sodium and Chloride account for 85% of the dissolved solids (solutes) in sea water.

• This makes it various degrees of SALINE: “total amount of salt dissolved in sea water”

Figure 3.05

SeaWater

• WHERE does the “salt” come from?

• And WHAT else is in the water?

Salinity

• The total amount of dissolved salts in seawater

• Measured in parts per thousand (ppt or o/oo)

• Average salinity of sea water is 35%

Density of (sea)water

• Density also affects the salinity of water

• Liquid water gets denser as the temperature decreases

• BUT ice is LESS dense than liquid water

• Increases with decreasing temperature

• Increases with increasing salinity

Temp. of ocean surface: cold = blue, warm = redTypical Ocean temp. range are 28-86 degrees F

Stratified Ocean (3 Layers)

• Salinity, Temperature and Density all effect ocean waters giving OCEAN GRADIENTS or stratified layers.

• Dense, cold water @ bottom

• Less dense, warmer water @ surface (floating on layer below)

3 layered Ocean

• Surface “mixed” layer: 100-200 m thick

• Mid “intermediate” layer: 200-1500 m thick contains the main thermocline (transition zone between warm and cold top/bottom layers)

• Deep “bottom” layer: after 1500 m

Figure 3.17

Figure 3.25

Figure 3.21

Figure 3.15a

Water, salinity, light, pressure, depth

• How does this affect marine “life?”

Light in the ocean

• Transparency depends on what is suspended in the water

• Different colors penetrate to different depths

Figure 3.11

Figure 3.11

Pressure

• Water is heavier than air

• Pressure changes ( a lot!) w/ increased water depth

• 1 atm. of pressure = sea level (on land) but in ocean each 10 m of depth (33’) you add another atm. of pressure

Figure 3.13

Figure 3.14

Groupers swim bladder has expanded, due to pressure, thus stomach has Been forced through mouth!

Buoyancy

Two deep-sea fishes on the deck of a ship after being hauled up from a depth of 800 m. Both fishes were seriously damaged and distorted by the rapid expansion of gases in their swim

bladders as they were brought to the surface.

Buoyancy

Fnft: A physoclistous swim bladder and associated blood vessels.

Life in the Ocean

• Deal with challenges that are unique to marine environment

• Must maintain suitable conditions inside the organism’s body

Diffusion & Osmosis

• Diffusion: movement of molecules from an area of HIGH concentration to an area of LOW concentration (things flow DOWNHILL)

• Osmosis: WATERS movement! The diffusion of water across a cell membrane. Water moves in opposite direction as solutes (“stuff” in water)

OsmosisOsmosis

More water

molecules

Fewer water

molecules

water

High to low concentrationflow

OsmosisOsmosisWatery environment

Inside of the cell

Plasma membrane

OsmosisOsmosis

• The amount of all dissolved molecules, or solutessolutes, in a solution is called the osmotic concentrationosmotic concentration.

• If the number of solute molecules in two solutions is equal (the osmotic concentration is equal), the solution is isotonicisotonic.

• If the two solutions have unequal osmotic concentrations, the solution with the higher concentrations of solutes is hypertonichypertonic; the solution with the lower concentration of solutes is hypotonichypotonic.

IsotonicIsotonicEqual number of solute molecules

No net movement of water molecules

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Hypertonic and HypotonicHypertonic and Hypotonic

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Hypertonic Hypotonic

More solutes; fewer water molecules

Fewer solutes;

more water molecules

water

Images : Copyright © The McGraw-Hill Companies, Inc.

More solutes;

fewer water molecules

Fewer solutes; more

water molecules

Hypertonic Hypotonic

Tonicity isSOLUTESOnly (not water)

Water always moves from hypotonichypotonic (fewer solutes) to hypertonichypertonic (more solutes) solutions.

Images : Copyright © Pearson Education, Inc.

HypertonicHypotonic

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Water always moves from hypotonichypotonic (more water) to hypertonichypertonic (less water) solutions

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HypertonicHypotonic

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678

910

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920

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Hypertonic Isotonic Hypotonic

Figure 4.13b

Figure 4.13a

More salt in cell,Water diffuses into cell, it will swelland burst.HYPOTONIC(“o” = swell)

Figure 4.13c

More salt outside cell,Water moves Out of cell, it will shrivel.HYPERTONIC(“e” = shrivel)

Osmosis in fish

• OSMOCONFORMERS: Internal concentration of ions CHANGES with changing environment around it (usually dealing with salt). Marine Inverts are like this (& hagfish).

• (Opposite) OSMOREGULATOR: control of internal concentrations. These are your vertebrates (from “Sharks”, fish, & up)!

Figure 4.14a

Osmoregulator: Because salt conc. HIGHER outside the water will flow OUT & dehydrate fish. Instead fish will drink water (increasing salt) to increase water (& not urinate it out) & then pass excess salt out through gills to “balance” itself

Hawksbills’ “excrete” glands (near eyes) to get rid of excess saltosmoregulator

Temperature

• How does this effect marine organisms?

• It dictates where they live and metabolize

Temperature regions of the worlds oceans

Temperature Regulation

• Most marine animals are ectotherms (“cold-blooded”)

Temperature Regulation

• Most marine animals are ectotherms (“cold-blooded”)

• Mammals and birds are endotherms– Use fat, feathers for insulation

Temperature

• Most marine animals are adapted to living at a specific temperature– Temperature determines species ranges

New Topic

• Tides…

Tides

• Tides

• Tide Tables

• Waves

• Weather (resultant)

Tides

• How do we calculate tides?

• Tide tables

• Semidiurnal Tides (in Northeast)

• Spring vs. Neap tides

Tides…

• …effect marine life too…

Low Tide…and offshore

Thailand, Tsunami

Grunion

Waves

Orbits

Waves in a Bay

Hitting the shore