Intro to Marine Biology Oceanography Chapter 1

Challenger Information 3 ½ year voyage around the world to collect data. 3 ½ year voyage around the world to collect data. Ship was an old warship modified into a research vessel. Left one cannon on to discourage pirates! Ship was an old warship modified into a research vessel. Left one cannon on to discourage pirates! Discovered so much information that it took 19 years to publish 50 thick volumes Discovered so much information that it took 19 years to publish 50 thick volumes 4,700 new species discovered 4,700 new species discovered Chief scientist was Charles Wyville Thomson Chief scientist was Charles Wyville Thomson Major importance of the voyage was that the azoic theory (which states that life could not live in the deep ocean) was proved wrong! Major importance of the voyage was that the azoic theory (which states that life could not live in the deep ocean) was proved wrong!

Major Ocean Basins Oceans cover 71% of the planet’s surface Oceans cover 71% of the planet’s surface PacificAtlantic Indian Arctic Southern Ocean PacificAtlantic Indian Arctic Southern Ocean

Sea vs. Gulf Sea – a body of salt water smaller than an ocean that is more or less land locked. Sea – a body of salt water smaller than an ocean that is more or less land locked. Gulf – a smaller body of water that is mostly cut off from the larger ocean by land formations. Gulf – a smaller body of water that is mostly cut off from the larger ocean by land formations.

Salinity Salinity - total amount of salt dissolved in water. Salinity - total amount of salt dissolved in 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 salt 1000g of water evaporate = 35 g of salt We express salinity in parts per thousand (35 p.p.t.) We express salinity in parts per thousand (35 p.p.t.) Salinity follows the rule of constant proportions – the proportions of the ions in sea water remain constant to each other. Salinity follows the rule of constant proportions – the proportions of the ions in sea water remain constant to each other. SodiumChlorideSulferMagnesiumCalciumPotassium Bicarb. 55%30%8%4%1%1%.5%

Measuring Salinity Salinity can be measured using a Niskin bottle. Salinity can be measured using a Niskin bottle.

What affects surface salinity? 1. evaporation2. thawing 1. evaporation2. thawing 3. precipitation4. freshwater run-off 3. precipitation4. freshwater run-off 5. freezing 5. freezing

Surface Salinity in the World’s Oceans freezing – high salinity 60 – Rain – low salinity 30 – deserts –high salinity 0 – heavy rain = low salinity

Salinity Summary TemperatureSalinityDensity WarmLowLow ColdHighHigh

Transparency One of the most biologically important properties of sea water is that sunlight can penetrate it. This is good because photosynthesis can occur. One of the most biologically important properties of sea water is that sunlight can penetrate it. This is good because photosynthesis can occur. The ocean reflects blue light best….…other colors are absorbed more than blue. The ocean reflects blue light best….…other colors are absorbed more than blue. Things that appear red at the surface look black at depth because there is no red light to reflect off them. Things that appear red at the surface look black at depth because there is no red light to reflect off them.

Pressure Land organisms are under 1 atmosphere of pressure (14.7 pounds per square inch (p.s.i.) Land organisms are under 1 atmosphere of pressure (14.7 pounds per square inch (p.s.i.) Marine organisms are under much more due to air pressure and water pressure (water weighs more than air). Marine organisms are under much more due to air pressure and water pressure (water weighs more than air). Gas filled structures like air bladders and lungs are compressed. Gas filled structures like air bladders and lungs are compressed.