Starter Activity• Come in & sit quietly• Turn in any homework you may be missing• Come up with 3 research topics related to marine science

that you would be interested in pursuing. No two people should have the same 3 topics.

LIFE IN THE OCEANPt. 3

Physical Factor: Temperature

•Rate at which chemical reactions occur largely depends on heat•Warmer -> increased rate

Physical Factor: Temperature

•Metabolic Rate – rate at which energy-releasing reactions proceed within an organism.• Increases with temperature

• Double at 18˚F temperature rise

Physical Factor: Temperature

•Ectothermic – “cold blooded” – internal temperature stays close to temperature of surroundings• Majority of marine life

Physical Factor: Temperature

•Endothermic – “warm blooded”•Mammals, birds, & larger, faster fish

Physical Factor: Temperature

•Warmer environments – higher metabolic rate • Grow faster• Faster heartbeat• Swim faster• Die faster

Physical Factor: Temperature

•Warmer environments – higher metabolic rate • Can’t get too hot – cook

• Can’t normally go higher than optimum temperature

• Can go colder – molecules simply slow down

Physical Factor: Temperature

•Endotherms can handle greater margin of external temperatures• Internal temperature only varies slightly

Physical Factor: Dissolved Nutrients

•Nitrogen & Phosphorus• Nitrogen in the ocean is about 1/10000 of that in topsoil

• Phosphorus is even more scarce• These are depleted during times of high productivity

Physical Factor: Salinity

•Cells are greatly affected by salinity• In the ocean the greatest variability occurs near the surface

Physical Factor: Salinity

•Variability along the surface:•As low as 6% around outer coast of Baltic Sea

•As high as 40% in the Red Sea

Physical Factor: Salinity

•More consistent at greater depths•Saltier

Physical Factor: Salinity

•Alter protein structure•Affects buoyancy•Can change the water balance of cells•Seawater is nearly equal to that of cells

Physical Factor: Dissolved Gases

•Oxygen – not easily dissolvable•Carbon Dioxide – easily dissolved

Physical Factor: Dissolved Gases

•Photosynthesis releases Oxygen, so Oxygen is more scarce below photosynthesis levels

Classwork & Homework

•Make your own crossword puzzle using your notes for the past 3 “Life in the Ocean” presentations. It must include at least 6 across & 6 down!