©1996, West Publishing Company (Modified by Asper, 2006) Slide 1 Lesson #1 Why do we Care About the...

©1996, West Publishing Company (Modified by Asper, 2006)©1996, West Publishing Company (Modified by Asper, 2006) Slide Slide 11

Lesson #1

Why do we Care About the Oceans?

MAR 151Vernon Asper

Department of Marine Science


What this course is not

• This course is NOT an oceanography course– That would require a lot of science

background; we require little– We will not cover all of the information an

oceanography course will cover– We will not deal with the nitty gritty of

equations and scientific terms


What this course is

• This course is intended for non science majors– We will discuss the oceans in terms of their

relevance to the world and society– This will require some background

information and some fundamental concepts• Terms• processes

– You will be required to think about what your are told, both by the professors and by the media.


Logistics of the Course

• Philosophy: – appreciate the oceans and how we depend on them – try to learn concepts rather than memorize

• The book:– We aren’t going to follow it chapter by chapter– Pay attention to major terms and concepts– More detail for those who are interested

• Class:– Attend!– The lectures and notes contain all of the material

that will be on the tests


Course Objectives

• to develop an appreciation for the oceans.

• to understand what goes on there and how it affects us

• To learn about natural and man-made changes in the earth and its climate

• To understand the truth (inconvenient or not) about climate change


What we’ll cover:

• Why do we care about the oceans? (climate, food, hurricanes, recreation)

• What are the oceans like? (Water, depth [topography], salinity, temperature, basic circulation, tides)

• How do we know about the oceans? (history of oceanography, activities of oceanography, waves)

• How did it get that way? (plate tectonics, sediments, shoreline processes)


More of what we’ll cover• Why is the sea salty? (creation of the solar

system, salinity)• What do fish eat? (food chains, productivity,

upwelling, ecology)• What eats fish? (marine mammals, predators,

birds, humans, fisheries)• What causes hurricanes and how do they affect

us?• What can we expect in the future? (El Nino,

global warming, sea level rise, loss of coastal wetlands, pollution)

• What is still to be learned about the ocean?


Why do we care about the oceans?

• Do they affect us?

• Do we affect them?

• Are they changing?

• How do we know?

• Would we even notice if they disappeared?

• Are we doing anything to them that might cause problems in the future?


How do the Oceans Affect Us?

• Climate

• Weather

• Food

• Recreation

• Transportation

• Energy


Are the Oceans Important?

• 2/3 of the earth’s surface.

• controls climate– El nio– ice ages

• controls atmosphere– Temperature– Chemistry

• Controls weather– Moisture– pressure


Climate• Climate is greatly affected by water masses in the

oceans. – The movement of large water masses redistributes heat

in the ocean.

• Since the oceans cover 70% of the Earth’s surface, this movement has a major affect on the overlying atmosphere and thus climate.


Climate• Coastal communities have a “milder” climate

than those further inland• Why? Water has an extraordinary ability to

hold and transport heat• Hold:

– Water has a high “heat capacity” (heat it can store)– Or the amount of

energy needed to raise it’s temperature

• Transport:– The oceans circulate


What is Heat Capacity

• Heat Capacity is the amount of energy required to make a substance get warmer

• Substances with a high heat capacity can absorb a lot of heat energy without getting a lot warmer.

• These substances can “store” a lot of heat, just like a battery stores electricity

• And, if the water is moving, the heat is transported from one place to another.


Heat Capacity

• If you have gram of water, you have to add 1 calorie of heat to make it 1 °C warmer

• By the way, 1 calorie (science term) is equal to 0.001 Calorie (food term)

• Or 1000 calories = 1 Calorie• (So one Coke, which has about 150 Calories (150 x 1000 calories),

has enough sugar energy to heat 4 Cokes (64 oz) from room temperature to boiling!)


Heat Capacity

• Compare water to other liquids:– Water’s heat capacity is 1.00 c/gm/°C – Alcohol is 0.58– Glycol antifreeze 0.50– Air is 0.24

• So if you want to store heat, water is 4 times more efficient than air– (like comparing a 4 Gigabyte card vs a 1 Gigabyte!)

• Therefore, a large body of water can heat or cool a LOT of air.

• This keeps coastal areas cool in the summer


Oceans and Climate• Sea breezes bring cool

air ashore• Caused by the land

heating more quickly than the sea

• This reverses at night and you get a “land breeze” but you only feel this out on the water


The Gulf Stream

• The Gulf Stream is a warm current that flows along the east coast of the US

• First mapped by Ben Franklin

• More complicated than he imagined


The Gulf Steam helps warm Europe

• Warm water flows across the ocean• Heat is

delivered to Europe

• Without this warming, Scotland would be about as cold as Greenland!


Climate vs. Weather

• Climate: what conditions are generally like– Average temperatures– Minimum and maximum temperatures– Rainfall– Wind

• What the conditions are like right now– Current temperature, rainfall, cloud cover– How conditions change over the short term


Mississippi Weather• We don’t really have weather in the summer• We have the same conditions every day:

– Highs in the low 90’s

– Lows at night around 80

– Humidity at 80%

– Afternoon thundershowers

• Repeat every

day from May

to September


Mississippi Weather• In the winter time, we do have weather• “fronts” pass through bringing good and bad

weather– Cold fronts bring

wind and clear weather– Warm fronts bring

precipitation

• We’ll go over this in more detail later– The concepts behind

our local weather are important for the ocean too

www.weatherunderground.comwww.weatherunderground.com


Global Climate Change

• Temperatures are warming!


Global Climate Change (Cont.)• As temperatures rise, ice will melt from

polar regions

• This would cause sea-level to rise.


• The rest of the story

• The long term temperature story:– Earth’s colder

now than it’s been for most of the last 150 million years!

– Earth warmed rapidly for 6,000 years

– Cooled again by ~1°C since then!


Climate Change

• We will devote a lot of time to these questions:– Is climate change real?– What do we think causes it?– How do we know?– How does it work?– How are the oceans involved?– What can we expect?– What should we do?


Hurricanes!

• Hurricanes are extreme low pressure areas– When one is coming, we stare at the

barometer– We watch the Weather Channel and see how

low can it go.

• By why is low pressure associated with a big storm?

• Why and how does the ocean feed a hurricane


Hurricanes!

• To understand hurricanes, we need to take a look at:– What “low pressure” is– What affects air density– What causes wind– Where the energy in a hurricane comes from– Why the spin– How they affect the ocean

• We’ll deal with all of this is “Lesson #8”


Hurricanes!


Katrina


Lost my FIB!

• Research tool• Note the USM logo


Katrina

• The coast will never be the same

• Massive destruction

• Recorded in tree rings

• Recorded in sediments

• Recorded in our memories


Katrina• Katrina was born in the ocean

• All energy came from the sea

• Without

water,

there can be

no

hurricane


Katrina• Storm

Surge• Wind

pushes the water

• Water floods the land

• Reason for all the damage


Katrina

• It could have been worse

• Katrina was only a Cat 3 when it landed


Why we care: Food!

• Natural fisheries– Commercial fishing operations

• Shrimp• Oysters• Finfish

– Recreational fishing

• Mariculture– Shrimp– Oysters– finfish


Why we care: Food!• World ocean fish production appears to

have leveled at between 80 and 90 million tons annually.


Why we care: Food!• Heavy fishing pressure has diminished the harvest of many species

– Cod is almost gone

• Some countries harvest more than others• We’ll discuss this later

– Limitations– management


Living Resources: Mariculture

• Mariculture is marine agriculture or fish farming of finfish, shell fish and algae.

• Mariculture requires raising the organisms under favorable conditions until they are large enough to be harvested for food.


Living Resources: Mariculture• For mariculture to be economically

viable the species must be:– Marketable.– Inexpensive to grow.– Trophically efficient.– At marketable size within 1 to 2 years.– Disease resistant.


Living Resources: Mariculture• Currently, about

one out of every four fish consumed spent part of its life in mariculture

• For some organisms the percentage supplied by mariculture is even larger.


Living Resources: Mariculture

• In the US, roughly 90% of the shrimp consumed are imported, pond-raised shrimp

• Biloxi processing plants process mostly imported shrimp

• No viable, commercial shrimp aquaculture program exists (yet) in the US

• Much morelater!

White Shrimp

Brown Shrimp

Pink Shrimp

This is a ghost shrimp, like we may This is a ghost shrimp, like we may catch on Horn Island. Not edible?catch on Horn Island. Not edible?


Why we care: Recreation!• Fishing

• Boating

• Scuba diving

• Beach basking

• Cruisinghttp://m.lasvegassun.com/news/2012/jan/14/us-italian-cruise-industry-http://m.lasvegassun.com/news/2012/jan/14/us-italian-cruise-industry-impact/impact/


$portfishingEconomic Impact of Sportishing—National Summary

(2008) Retail SalesAll Fishing $45,335,939,822Freshwater Fishing $25,035,000Saltwater Fishing $11,051,345,543Great Lakes $2,524,266,182

Key-biscayne.comKey-biscayne.com


Boating• Statistics are weak

– Each state handles its own registration

– Accidents are logged but activity is not closely monitored

• 78 million people use 17 million boats

• 1/3 of all households participate

• Activity increasing• Tied to fishing



SCUBA Diving• Oil rigs make great

habitat

• Great for diving

• Gulf of Mexico

is one of the

best spots

http://members.aol.com/UWBolten/Texas.htm


Beachgoing

• 40% of American families visit the beach each year

• More than 50% of US population lives within 50 miles of the beach



Transportation• The US

imports a lot of material

• Most of it comes by water.

• This requires ports, highways, railroads, etc.

Source: www.oceancommission.govSource: www.oceancommission.gov


OIL

• ~40% of our oil is produced domestically

• Of that, 25% comes from offshore sources

• Only the Gulf and Alaska allow new drilling today


Energy• Demand

continues to climb

• US production continues to decline

• Imports increase

• Politics abound

Wikimedia.orgWikimedia.org


Energy

• Guess where the oil is?

• Not much in the US

• Should we drill more?

• Is drilling safe?

http://api-ec.api.orghttp://api-ec.api.org


Energy

• Drilling is “relatively” safe

• Most input is from natural sources (really!)

• Outboard motors were a huge problem that is being addressed


Energy

• We’ll continue this discussion later:– Where does oil

come from?– CO2

– Gas– Hydrates– Alternative

fuels

Region Usage (quadrillion Btu)

US 98

Canada 14

Mexico 7

Asia 120

Central/South America

22

Africa 13

Europe 85


Why We’re Interested, Summary

• The oceans cover 70% of the earth’s surface• We depend on them for:

– Climate (the oceans control climate)

– Weather (hurricanes are born there)

– Food (fisheries and aquaculture)

– Recreation (boating, diving, beach-going)

– Transportation (imports and exports, cruises)

– Energy

• We will look at each of these in more detail and discover how they work

©1996, West Publishing Company (Modified by Asper, 2006) Slide 1 Lesson #1 Why do we Care About the...

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Transcript of ©1996, West Publishing Company (Modified by Asper, 2006) Slide 1 Lesson #1 Why do we Care About the...