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Biology 13- Marine Biology

Introductions

• Instructor: Dr. Kevin Raskoff• Email: kraskoff@mpc.edu• Phone: (831) 646-4132• Office: Life Science, 203B (upstairs)• Office hours: Mon-Thurs- 10-11; Thur 5-6pm;

or by arrangement. • The class website can be found at

http://www.mpcfaculty.net/kevin_raskoff/classes/classes.htmI can’t remember that!!!! How else can I find it?!

Class Introductions

• Name• Academic plan• Why are you here?• What is your comfort with science?• Something interesting about yourself.

Review of Syllabus

• What should you expect of this class?

• What do I expect of you?

• What should you expect of yourself?

• What is this class about?

Class WebsiteCan’t find it? Google “Raskoff”

http://www.mpcfaculty.net/kevin_raskoff/classes/marine/marine.htm

I’m going to get my textbook:

A. NewB. UsedC. From the LibraryD. Book? I have to read?!

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• Class Roster

So, what do you want to learn about in Marine Biology?

• Why is the ocean blue?

What the *#!@?Is this Marine Abiology?!

Teahupo'o, Tahiti

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Arctic Ctenophores Pelagic Snails

Amphipods The Wonderful World of Mucus!

Oceanic Nekton

How smart are Fishes?

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Marine Lakes

• Land-locked marine ecosystems

• Greatly simplified flora and fauna

• H2S- Hydrogen Sulfide layer

SubsAnd

ROVs

The Water!

• Molecular basics –a review• Physics of water• Salinity• Density• Pressure • pH• Dissolved Gases

What is one of the most importantthings in marine biology?

• How is it made?• Properties• Phases• Dissolving power

– What is a salt?– How does it do it?– What does it do to the water?– What does temperature do?

Lets looks at some water… Elements and Compounds

Salt…Lets look at some water…

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Chemical Reactions

2H2 + O2 = 2H20

Polar covalent bonds in a water molecule

Electronegativity: a measure of an atom’s “selfishness”, that is its ability to hold electrons.

Oxygen holds onto the electrons more, so it has a negative (-) charge, so the Hydrogen are positive (+)

OK, so what! I thought this was Marine Biology!!

Hydrogen Bonds• Polar molecules can

be weakly attracted to each other and form Hydrogen Bonds

• These Hydrogen (or Polar) Bonds give water a lot of interesting and important properties that matter to LIFE.

The ‘Magic’ of Water

1. Cohesion and AdhesionWater is attracted to other water (Co), and

to other things (Ad) by the polar charges in the molecule

2. High heat capacity3. High heat of evaporation4. High thermal

conductivity5. Less dense when frozen

The ‘Magic’ of WaterMakes it a very Stableenvironment for life

So?

The ‘Magic’ of Water6. Excellent biological solvent

• Solvent and solute• Water can dissolve most things, in bodies and ocean

NaCl vs. Na and Cl

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Test your understanding

Positively charged sodium and negatively charged chloride are examples of…

A. hydrogen bondsB. ionsC. moleculesD. atoms

Test your understanding

Hydrogen bonds in water molecules are formed between

A. hydrogen atoms of adjacent molecules.B. oxygen atoms of adjacent molecules.C. hydrogen and oxygen atoms of adjacent

molecules.D. two hydrogen atoms of the same

molecule.E. two oxygen atoms of the same molecule.

Chemical Dissociation• Salts, Acids, and Bases• pH a scale to measure acidity or alkalinity• Water is a great Buffer: compounds that

minimize changes in pH by binding excess H+ or OH- ions.

Ocean pH• World Ocean

range: 7.4-8.5 • Slightly

Basic… for now.

• The ocean is getting more acidic!

• Why?!

Dissolved Gasses• The amount of gas

dissolved in water (Gas Solubility) varies by temperature- cold water holds more gas

• Oxygen and CO2 concentrations vary greatly by depth and region

• Water has low Oxygen, but high CO2

Lets draw a graph…

Carbon Dioxide in water• CO2 + H2O ⇔ H2CO3 ⇔ H+ + HCO3

-⇔ H+ + CO32-

Carbon Water Carbonic bicarbonate carbonateDioxide Acid

• Bicarbonate ion is the major reservoir of CO2 in the sea. (7th most common ion), and a BIG Buffer

• About 50x more CO2 in water than in air! Why???

• Have you heard about CO2 anywhere else?Know this stuff! This will be important! In this class and you life.

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The Acid Ocean• While we worry over atmospheric

climate change, the real crisis of the 21st century will probably be in the Ocean.

• The battlefield of that crisis is the Pacific, and Monterey Bay is Ground Zero.

• What will be the ecology of the acid ocean? How will the food chain be altered? What management practices will need to be changed?

6.8 7.0 7.2 7.4 7.6 7.8 8.0 8.2

Dep

th (m

)

0

1000

2000

3000

4000

5000

6000

Central PacificWestern PacificNorth PacificAntarctic PacificEastern Pacific

Ocean Acidification

Additional stresses for animals that are already food-limited –

“Living on the edge”

The oceans absorb most of our CO2 emissions

When CO2 dissolves into the water it form Carbonic Acid.

pH variation in the Pacific Ocean

Data from Jim Barry, MBARI

Sinking O

rganic Debris

Future Ocean Food Web – Loss of biodiversity, low productivity, dominated by microbial recycling?

Microbial R

emineralization

Primary P

roducers

Zooplankton food web Upper Trophic levels

Seafloor community

Simplified Food Web,Increased Microbial Dominance

What are the expected effects of An acidified Ocean?

Test your understanding

Explain the fate of CO2 in the ocean. In your explanation address the 3 carbon dioxide “reservoirs” in the sea, which form is most of the CO2 found, and the impact on ocean pH of increasing atmospheric CO2concentrations

Salinity• Salinity

– Total concentration of dissolved inorganic solids

– “Ocean” water varies from 3.3% to 3.7% , but we usually talk about ppt or ‰. Average=3.5%

• (33 to 37 ppt, PSU, or unit-less)– Major Constituents of seawater

(top 6)• Chloride (Cl-) = 55.04%• Sodium (Na+) = 30.61%• Sulfate (SO4

2-) = 7.68%• Magnesium (Mg2+) = 3.69%• Calcium (Ca2+) = 1.16%• Potassium (K+) = 1.10%

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total 99.28%

About 2.2 lbs of salt in 1 cu ft. of water, which is about 2 tbsp/liter

Trace Ions• Several trace elements can also be limiting, these

are called micronutrient most notably is iron and Si. Other metals like Cd, Zn, Ni, Cu, Se are depleted in surface waters

• Principle of Constant Proportions Early studies: found total salinity varied (as water is added and removed), but ratio of one major ion to another was constant throughout the ocean.

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Where does the salt come from?Test your understanding

The average salinity of seawater in the open ocean is

A. 30 ‰B. 33 ‰C. 35 ‰D. 40 ‰

The Ocean is getting:

A. FresherB. SaltierC. Staying about the same

Temperature and Density• Temperature and Solar Energy• Density is factor of salinity and temperature

D = Mass / Volume

Clines in the Ocean Physical Environment• Clines of all sorts “structure” the open

water habitat. Regions of rapid change.• Temp, salinity, oxygen, nutrients, etc…

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Figure 3.15b Pressure

• Product of:– Depth– Salinity– Temperature– Dissolved Items– Atmospheric

Pressure

An animal living at 100 meters deals with a pressure of:

A. 5 ATMB. 9 ATMC. 10 ATMD. 11 ATM

Light in the ocean“White” light is made of all the colors

Physical- Light

• Variation in wavelengths through water

Compensation Depth ≈ 1% surface intensity

PAR-Photosynthetically Available Radiation

Count available photons, not just all wavelengths

Where does the light go?• Light is Scattered by:

– Suspended particles (Sediment “soil”, plankton, etc.)

– Dissolved material• Light is Absorbed by:

– Phytoplankton: used in photosynthesis, converted to chemical energy

– Water molecules: converted to heatThis scattering and absorption

impact the colors differently

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Measuring Water Clarity

•Secchi Disk•Other more complicated methods

• So…Why is the ocean blue?– The rates of scattering and absorption are

LOWEST for blue, so blue light makes it down to greater depths and is more available for reflecting back to the surface.

Importance of light in the sea• Sunlight absorbed by the water is converted to

heat.– This heat warms the upper portions of the water.– It also provides the energy for evaporation and the

winds.• Photosynthesizing organisms (“plants”) are

the main source of the food in the ocean!– The depth at which light penetrates the ocean

controls the depth to which these organisms can occur.

– This zone is called the Photic Zone.

Other biological impacts of light• Light influenced movement

– Daily Vertical Migration• Many different groups of animals migrate up and

down in the water with the changing light intensity. • They typically come up to the surface to feed at

night, then swim back down at dawn to escape their predators.

• Many swim 100s of meters a night.

• Coloration of animals– In the open ocean there is no where to hide! – Many animals have evolved interesting ways to

deal with this issue using color.

In deeper waters many animals are brightly colored

• Red, orange, and yellow are particularly popular.

• Animals which are red, yellow, or even green would look blackblack with the available light.

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Intensity changesWith time of day

With other biomass

With turbidity

With season