Intro to Marine BiologyIntro to Marine BiologyOceanographyOceanography

Chapter 1Chapter 1

Challenger InformationChallenger Information

• 3 ½ year voyage around the world to collect 3 ½ year voyage around the world to collect data.data.

• Ship was an old warship modified into a Ship was an old warship modified into a research vessel. Left one cannon on to research vessel. Left one cannon on to discourage pirates!discourage pirates!

• Discovered so much information that it took Discovered so much information that it took 19 years to publish 50 thick volumes19 years to publish 50 thick volumes

• 4,700 new species discovered4,700 new species discovered• Chief scientist was Charles Wyville ThomsonChief scientist was Charles Wyville Thomson• Major importance of the voyage was that Major importance of the voyage was that

the azoic theory (which states that life the azoic theory (which states that life could not live in the deep ocean) was could not live in the deep ocean) was proved wrong!proved wrong!

Major Ocean BasinsMajor Ocean Basins• Oceans cover 71% of the planet’s surfaceOceans cover 71% of the planet’s surface

• PacificPacific AtlanticAtlantic Indian Indian Arctic Arctic Southern Southern OceanOcean

Sea vs. GulfSea vs. Gulf• Sea – a body of salt water smaller than Sea – a body of salt water smaller than

an ocean that is more or less land locked.an ocean that is more or less land locked.

• Gulf – a smaller body of water that is Gulf – a smaller body of water that is mostly cut off from the larger ocean by mostly cut off from the larger ocean by land formations. land formations.

SalinitySalinity

• SalinitySalinity - total amount of salt dissolved in - total amount of salt dissolved in water.water.

• 3.5% “salt” and 96.5% water by mass.3.5% “salt” and 96.5% water by mass.• 1000g of water evaporate = 35 g of salt1000g of water evaporate = 35 g of salt• We express salinity in parts per thousand We express salinity in parts per thousand

(35 p.p.t.)(35 p.p.t.)• Salinity follows the rule of constant Salinity follows the rule of constant

proportions – the proportions of the ions in proportions – the proportions of the ions in sea water remain constant to each other. sea water remain constant to each other.

SodiuSodiumm

ChloridChloridee

SulferSulfer MagnesiuMagnesiumm

CalciuCalciumm

PotassiuPotassiumm

BicarBicarb.b.

55%55% 30%30% 8%8% 4%4% 1%1% 1%1% .5%.5%

Measuring SalinityMeasuring Salinity• Salinity can be measured using a Salinity can be measured using a

Niskin bottle.Niskin bottle.

What affects surface salinity?What affects surface salinity?• 1. 1. evaporationevaporation 2. thawing2. thawing

• 3. precipitation3. precipitation 4. freshwater run-off4. freshwater run-off

• 5. freezing5. freezing

Surface Salinity in the World’s Oceans Surface Salinity in the World’s Oceans

30

0

30

60

90

60

90 - freezing – high salinity

60 – Rain – low salinity

30 – deserts –high salinity

0 – heavy rain = low salinity

Salinity SummarySalinity Summary

TemperatureTemperature Salinity Salinity DensityDensity

WarmWarm LowLow LowLow

ColdCold HighHigh HighHigh

TransparencTransparency y

• One of the most One of the most biologically biologically important important properties of sea properties of sea water is that water is that sunlight can sunlight can penetrate it. This penetrate it. This is good because is good because photosynthesis photosynthesis can occur.can occur.

• The ocean The ocean reflectsreflects blue light best….…blue light best….…other colors are other colors are absorbedabsorbed more more than blue.than blue.

• Things that appear Things that appear red at the surface red at the surface look black at depth look black at depth because there is because there is no red light to no red light to reflect off them.reflect off them.

PressurePressure• Land organisms are Land organisms are

under 1 atmosphere of under 1 atmosphere of pressure (14.7 pounds pressure (14.7 pounds per square inch (p.s.i.) per square inch (p.s.i.)

• Marine organisms are Marine organisms are under much more due under much more due to air pressure and to air pressure and water pressure (water water pressure (water weighs more than air). weighs more than air).

• Gas filled structures Gas filled structures like air bladders and like air bladders and lungs are compressedlungs are compressed..