Survey of Oceanography
Lectures Schedule for Spring 2004
This is a general outline of the material for the web-based
course. It is laid out to correspond with another course I will teach
at the same
time, so if you are in College Station, you are invited to attend the
class. The outline is meant to be an overview of the topics to be discussed
in roughly the order they will be discussed. Some topics may take more
or less time than listed.
21-23 January 2004
- Please read Course Goals and
the Syllabus.
- Much of the material for this course comes from the web. Read Using
the Web for more information on how to judge the value of web-based
information.
- Next, let's look at why we want to study the oceans, and why the
material presented in this course differs from that in the typical
oceanography
course. Please read Oceanography
is Changing Rapidly, and Why
Study the Oceans?
C02
and the Role of the Ocean in Climate
You may have read that climate is warming, that
the warming will lead to disaster if we don't stop burning fossil fuels,
and that we may be required to stop driving our cars. What's happening?
Is it really that bad? Are there other ways to solve the problem? Isn't
earth just warming up naturally as a result of coming out of the last
ice age?
26 January 2004 - The
C02 Problem
28 January 2004 - What
is the Evidence for Global Warming?
30 January 2004 - Earth's
Radiation Balance, Oceanic Heat Fluxes
2 February 2004 - Abrupt
Climate Change and the Ocean's Circulation
Homework 1 Due
4 February 2004 - Carbon
Cycle in the Ocean and the Iron Hypothesis
6 February 2004 - Modeling
the Climate System
9 February 2004 - Policy
Implications
Homework 2 Due
El Niño and Role of Ocean in Weather
El Niño is influencing the weather everywhere according to lots of newspaper
articles. Or is it really El Niño that is causing changes in the weather?
Why should events in the equatorial Pacific be so much in the news? How
can events so far away influence our weather?
11 February 2004 - Tropical
Heat Budgets
13 February 2004 - Equatorial
Currents and Typical El Niño and Observing
the Tropical Pacific
Definition: El Niño is
a disruption of the ocean-atmosphere system in the tropical
Pacific having important consequences for weather
and climate around the globe - NOAA.
16 February 2004 - I am attending the joint meeting of
the American Society of Limnology and Oceanography and The Oceanography
Society in Hawaii this week.
Work on your term paper
Homework 3 Due
18 February 2004 - No class today.
20 February 2004 - No class today.
23 February 2004 - Forecasting El Niño and Teleconnections
Some results of the meeting in Hawaii:
- All coral reefs are degraded compared with pre-human reefs.
- 30 Million more people
move into the coastal zone each year worldwide, leading
to increased degradation of oceanic resources
and the environment. We
must now study this urban
ocean.
- There are more bacteria in the sea than there are stars in the
known universe.
- Thousands of tuna, dolphins, and other animals are being tagged
and followed for months to years, leading to completely new understanding
of where they go in the ocean to live and breed.
- The idea of a species does
not work with bacteria. There is a complete range of DNA
and RNA similarity ranging from
practically identical to very different.
- The charismatic megafauna is mostly gone: fishes, dolphins,
turtles, sharks, and whales are down to a small fraction
of their original
populations. Why are so many places in the Caribbean
called Tortuga (turtle)?
- Microbial ecology is hot.
25 February 2004 - Policy
Implications
No recorded lecture today due to equipment problems.
29 (Sunday) February 2004 - Quiz
1 at 1:00 PM
This is an open book quiz covering Global Change and
the role of the ocean in climate change,El Niñoand the role of the ocean in changing
weather patterns. You will have one hour to complete the quiz and email
me answers after the quiz has been uploaded to the web.The link above
will go active when the quiz is available.
Fisheries: The Ocean as Food Source
Where are my Orange Roughy?
Julie loved orange roughy. She liked it even better than catfish. Her
mother liked it because it was cheap compared with most other fish at
the market. But now it was seldom for sale. Her mother asked the manager
at the fish counter and he said he couldn't get it any more.
Can we help Julie?
Can we find out what happened to the
orange roughy? To prepare for this section, look up orange roughy at http://www.fishbase.org/search.cfm so
we know what fish we are learning about. Then write down possible explanations
of why the fish is no longer sold. For example, few were sold so the
market
stopped carrying it. etc.
1 March 2004 - Fisheries:
An Introduction
- Why do we care about fisheries? How important are fisheries
to the economy of any region? Get an overview of the scientific
and policy issues from the American Association for the Advancement
of Science, the publishers of Science.
Then learn a little about recreational
fisheries, and commercial fisheries
in this country. You can download a brochure on
recreational fisheries in the Gulf of Mexico for more details.
Get the total
value of all fish landed by commercial fisheries in the US
in 2002 (use the default value for the search), then get the total
value for all
fish caught in Texas for 2002.
- The basic question is: How many fish can
be harvested from the sea? The answer is not simple. Some
fish stocks are declining. Is the decline
due to overfishing? is it due indirectly to fishing for other types
of fish? Or is it due to the natural variability of the stock? If
it
is due to overfishing, what can be done? Reduce the number of ships?
Limit the fishing season?
- Here is a brief quote from National Geographic magazine's
article on Cuba Reefs: A Last Caribbean Refuge in the February
2004 issue.
It
was almost like a hallucination. Immediate.
A sense of dislocation. Something was awry.. I had flopped
overboard from
a dinghy
on a glassy Caribbean sea in the summer of
the year 2000 and
in an instant,
apparently,
slipped backward nearly half a century
into an underwater realm that had not existed, so far as I knew,
since the 1950s...
Residents swarmed
over me, welcoming me to the neighborhood,
animals in numbers and diversity I hadn't seen in decades,
not since Lyndon
Johnson
was president.. Schools of yellowtail
snappers
and blue creole wrasses darted about
in a frenzy.. A squadron of glittering
tarpon passed regally by,
... Green moray eels slid part way
out of their crevice homes,...
What is the
tragedy of the commons? The term was used by Garrett
Hardin in his now famous article in
Science in 1968. Hardin, Garret.
"The Tragedy of the Commons." Science,
1968. 162:1243-8.
3 March 2004 - Fish
and Fisheries
- Where are the major fisheries of the world? That is, where do fish
live in the ocean? Are they found in the deep, open ocean, along
coasts,
what coasts, on continental shelves, or where? Where are different
commercial fish found? Are tuna caught in the same areas as sardines?
Learn about
cod at the cod
page maintained by the Woods Hole Oceanographic Institution.
Read about the distribution of a few other Atlantic
fish at the same site. As you browse through the information,
notice the shape of the fish. Some such as Atlantic mackerel are
streamlined
to be able to swim fast to catch other fish, others such as flounder
are shaped to hide in the bottom. Notice form follows function.
Can
you look at the shape of an unfamiliar fish and deduce something
about its habits? Note: If your browser supports java script, the
picture
of the fish pops up as you put the curser over the name of the
fish on the Atlantic fish site.
- Then learn about Alaskan Fish (use
pull-down species menu) and view this animation of where
Alaskan pollock were caught in 2001. (You can view other maps
by at the Map
Page for the Alaska Fisheries
Science Center).
- See if there is pattern in the distribution of fish caught as food.
As you browse through the information, notice the shape of the fish.
Some such as Atlantic mackerel are streamlined to be able to swim
fast
to catch other fish, others such as flounder are shaped to hide
in the bottom. Notice form follows function. Can you look at the
shape of an
unfamiliar fish and deduce something about its habits? Note: If
your browser supports java script, the picture of the fish pops up
as you
put the curser over the name of the fish on the Atlantic fish site.
- For more information on fish, go to the fishbase data
site, there, for example you can find Tuna information, Cod information,
and red
snapper information.
5 March 2004 - Marine
Food Webs
- The sunlit upper layers of the ocean, called the euphotic zone,
are home to vast numbers of marine plants called phytoplankton. They
include diatoms, dinoflagellates,
and coccolithophores.
The marine plants are Eukaryota,
organisms with cells with a nucleus. Most phytoplankton are one-celled
plants called protists.
The plants use solar energy to convert CO2 and nutrients into living
material.
The plants are eaten by the smallest floating animals, the zooplankton,
such as copepods. The small zooplankton are in turn are eaten by
larger
zooplankton such as jellyfish.
Zooplankton are eaten by small fish such as sardines, herring,
and squid,
(see also here)
and small fish are eaten by larger fish. This is a simple example
of a
marine food
web.
- All our ideas of life in the sea are rapidly changing. We now know
that the food web is dominated by micro, nano, and pico plankton.
Yet
we know little about these organisms. They are too small to see
easily or study, they cannot be cultured, and they tend to all look
alike.
We can separate them using such techniques as DNA analysis, and
the analysis is leading to remarkable discoveries. Life in the sea
is much
more diverse than we expected. All life is now known to be in three
domains. And all three are very common in the ocean. Click
on any of the three domains and explore the microscopic world.
8 March 2004 - Global
Distribution of Phytoplankton and Upwelling Regions
- The distribution of phytoplankton in the ocean can be measured
by color scanners in space. The first was the Coastal
Zone Color Scanner launched in 1979 on the satellite Nimbus-7.
It was followed many years later by the SeaWiFS on
Landsat launched in 1997 on the Seastar spacecraft and MODIS (Moderate
Resolution Imaging Spectrometer) on the Terra spacecraft launched
in 1999. To understand how the instrument measures plankton, and
why the
measurements are important, see Studying
Ocean Color From Space Teacher's Guide with Activities or the
tutorial What Color is the Ocean
- and why do you need a satellite to tell you? The SeaWIFS
Project held a Teachers
Workshop that gives more information.
- If we look at the global
image calculated from all Coastal Zone Color Scanner data
collected from 1979 to 1986, we can see where in the ocean phytoplankton
are found.
A really big image (327 KBytes) is here.
The color scale ranges from 0.1 milligram per cubic meter of chlorophyll
pigment (purple) to 10 milligrams per cubic meter (red). This was
the
first global view of the distribution of phytoplankton in the ocean.
We see that the phytoplankton are mostly along coasts, and in high
latitude
oceanic areas in spring and summer. Why such large concentrations
near coasts? Monthly, global maps of chlorophyll,
and other data are available from the SeaWiFS site.
- Ekman showed that winds blowing on the sea force
water very close to the surface to move at an angle of 45° to the right of
the wind
in the northern hemisphere. Currents at deeper levels move at larger
angles. Summing up all the currents, we find that the transport is
90° to the right of the wind. Winds blowing toward the
poles along the west coasts of continents push water offshore
away from
the coast.
The water is replaced by upwelling water. The upwelled
water is cold and rich in nutrients (fertilizer for phytoplankton).
The upwelled
water
feeds a local fishery, and it influences the local climate.
Find out more by reading Chapter 11, the theory
of the Ekman layer, and Applications
of Ekman
Transports. Pay attention to Figure
9.3 and equations 9.14 and 9.16. I don't expect you to understand
the mathematics in the first section, but notice what approximations
were used to derive the results, and the nature of Ekman currents
(the
form of the solutions) graphed in several plots.
- How Ekman currents leads to coastal upwelling is described in the Chapter
2. The Benguela Upwelling Zone published by the SeaWiFS Project
at the Goddard Space Flight Center of NASA.
Homework 4 Due
10 March 2004 - Invertebrates:
The Other Marine Food Source
- The problem of overfishing is not limited to fish. We catch
and eat many other marine animals including shrimp.
crabs, clams, lobsters, oysters, and scallops. Shrimp News publishes
a guide to the Farmed Species Shrimp.
- Where do these creatures live? What do they eat? What eats them?
How many are there? How are they affected by coastal development?
Lets concentrate
on one class: shrimp. How are shrimp raised? What factors influence
shrimp farming? How does shrimp farming influence the environment?
Get
a good overview from Shrimp
News (updated October 2003). Dr. Louis Landesman has written
in 1994 on the negative
influence of aquaculture on the environment. I have searched
for more up-to-date info, but everything I found was many years
old. Because
environmental problems also lead to failure of the shrimp farms,
many of the worst practices are being replaced by better practices.
- Shrimp farming needs a constant supply of shrimp larvae or broodstock
(See Hawaiian hatchery),
shrimp ponds replace mangroves, the growing shrimp need lots of high
protein food (See Brine
Shrimp for Feedstock), some of which comes from the sea, and
they produce waste water. Shrimp farmers can reduce environmental
damage,
and by raising shrimp reduce the need to fish wild shrimp. About
half the shrimp sold today are raised on farms. The remainder come
from such
areas as the Texas gulf coast, which supports a major shrimp industry
($194,000,000 in 1999 compared with $9,000,000 for all fish from
the
Texas coastal waters). Find out more at the Texas
Shrimp Farming site.
12 March 2004 - Policy
Implications
- Most fish stocks throughout the ocean are overfished despite fisheries
regulations. Read this very important article by Jeremy Jackson and
colleagues on Historical
Overfishing and the Recent Collapse of Coastal Ecosystems from
Science (2001), Volume 293,
pages 629 to 638, in which they show that "Historical
abundances of large consumer species were fantastically
large in
comparison with recent observations."
- Why? Here are some issues from
Habitat Media and a PBS series. The
Monterey Bay Aquarium has similar information on Fisheries
in Trouble. The problems include overfishing, reduced fish
stocks, bycatch, fishing lower down on the food chain (lower trophic
levels),
and destruction of bottom organisms and habitat by bottom trawling.
Fish have no where to hide. Even National Marine Sanctuaries regulations do not restrict fishing.
- Think Locally: Which fish should we eat, which should we avoid
because they are overfished or because fishing harms the environment?
See the
Monterey Bay Aquarium's Seafood
Watch, their list
of fish to eat or not eat, and the Audubon Society's Seafood
Guide.
What is Texas government doing to reduce overfishing
of shrimp and environmental problems of shrimping?
A really good overview is given in the Texas Parks and Wildlife Texas
Shrimp Industry Report of Sept 2002, but this is a large file
(5.9 Mb). Otherwise start at Texas
Parks and Wildlife Coastal
Fisheries Information. Also see Recommendation
for 2004.
15 March 2004 - 19 March 2004 Spring
Break
22 March 2004 - No Lecture
Coastal Erosion
Galveston has spent millions replenishing their beach. Yet it continues
to disappear. Isn't there anything that can be done to keep the beach
sand in place?
24 March 2004 - Coastal
Erosion. An Introduction
- Film: Portrait
of a Coast. This is a beautiful film that
follows the seasonal cycle of a New England coast noting
problems caused by coastal development. While watching
the film try to remember:
- Why are beaches important?
- What is the seasonal cycle of the beach? When
is it highest, when lowest?
- What processes influence the beach?
- How does coastal development lead to problems?
- What are the problems?
- Read this Coastal
Erosion Case Study of Cape Cod before class.
- Coastal erosion is a problem for those who live near coasts and
for marine organisms living along the coast. What is the nature of
the problem?
Are we making it better or worse? What causes erosion? Can it be
prevented? Or do we want to allow erosion as a natural process?
- The problems seen in the film are starkly highlighted at a coastal
development on a Carolina coast, the Shell
Island problem. Shell Island Resort is located on an offshore
island, and an inlet at one end of the island is moving rapidly
toward the resort.
When it reaches the resort, the resort will be destroyed. The site
outlines the problem, then provides background information on:
What can be done?
Should anything be done? Who should pay for any work?
Homework 5 Due
26 March 2004 - Types
of Coasts, the Geological Setting.
- The type of beach is determined mostly by the geological
setting from Jim
Durbin at the University of Southern Indiana.
Plate tectonics and continental drift play a major role as do the types
of rocks and sediments along the coast. The coast can be dominated by
rocks or sediments. It can be rising or sinking. More information from
Jim Durbin here (Scroll
to bottom of page, and continue to the next page).
Beach Processes. Shoaling and Breaking Waves,
Sand Transport.
- Waves breaking on the beach lose energy and
create turbulence.
Small waves carry sand up higher on the beach. Storm
waves erode the beach
and carry sand offshore. The water poured into the
surf zone by breaking waves runs off in currents which carry sand
along
the bottom.
Tides
raise and lower sea level and modulate these processes.
See Pamela
Gore's Shoreline and Coastal Processes Web Page.
29 March 2004 - Ocean
wave Theory, Wave Measurement and Prediction
- Ocean waves are made by the wind: The faster
the wind, and the longer it blows, the bigger the wave. The biggest
waves
are made by storm
winds blowing for days over distances of thousands of
kilometers in the North Pacific, the Antarctic region, and the North
Atlantic.
Read Chapter
6 of the Principles of Oceanography. Further ocean wave
theory, with more equations is at Chapter
16 of Introduction to Physical oceanography. A simple
explanation of wave theory is at the waves
section of the oceanography
book published by Seafriends
Marine Conservation and Education Centre.
- Where are the biggest waves in the world today?
To answer the question, you can pick any day before the class day,
it does not have to be the class day. Data are at the NOAA
Wavewatch Web Pages. Click on the Center Top pull-down menu
to select the region for the wave plot. You will need to plot Atlantic
Ocean from
global, Pacific Ocean from global, and Indian Ocean from global.
31 March 2004 - Beach
Processes
- Waves breaking at the beach deposit their energy in the coastal
zone. The energy is available to erode the beach, transport sand
along
the coast, carry sand higher up on the beach in summer, and to
generate
rip currents. All these processes can change the shape of coasts. The
processes are described in the Dunes
and Beaches section of the oceanography
book published by Seafriends
Marine Conservation and Education Centre. There is more
information about coastal processes in Chapter
17 of Introduction to Physical Oceanography.
- Now look at some specific examples. The US Geological Survey has
information on erosion
on the west coast, the loss of Florida
wetlands, and the erosion
due to Hurricane Dennis. These three sites and related pages
give a examples of the processes and their impact. Teachers can
find information
at Coasts
in Crisis.
2 April 2004 - Storm
Surges and
- Storms produce the greatest coastal changes. Great storms in
the middle ages removed tens of kilometers of Germany's coasts
in a few years. Hurricanes in the Gulf of Mexico move barrier islands,
flood nearby
land, and destroy coastal structures.
- The changes results from waves riding on a rise of sea level, the
storm surge. Many processes influence the height of the surge. Essentially,
hurricane force winds blowing onshore across tens of kilometers of
shallow
water pile up water along coast. The stronger the wind, the shallower
the water, and the greater the extent of shallow water, the higher
the
pile of water. In some cases it can exceed 3-4 meters. If the surge
occurs at high tide, the tide adds to the height of the surge. The
surge
can travel along the coast, causing high waters away from the strongest
winds. The Electronic
Storm Surge Atlas shows just what a storm surge would do to
buildings in various locations in North Carolina. More information
is in the online
textbook Introduction to Physical Oceanography under storm
surges. NOAA has a web page that describes the different categories
of storms according to the Saffir-Simpson
Hurricane Scale.
- Additional Reading: See the on-line tutorial on tsunamis maintained
by the University of Washington and NOAA's Pacific Marine Environmental
Laboratory. The NOAA Lab's pages provide more
information. Additional information on modeling tsunami
runup is at the US Corps of Engineers Coastal Engineering Research
Center. Photos of
damage are linked to this world
map published by the University of Southern California Tsunami
Research Group.
5 April 2004 - Policy
Implications
- Should we try to protect oceanfront property? The answer is
often determined by nature: Most solutions either do not work,
or they work for only a limited time.
- Who owns beach sand. Read how the California Coastal Commission
charges fees for keeping sand from reaching a Southern California
Beach. Report
on In-Lieu Fee Beach Sand Mitigation Program: San Diego County
- If we do allow protective structures, who should
pay. Remember the film Portrait of a Coast which began with footage
showing
a New England city that had been damaged by storms many times
in the past
century, and where the cost of protection exceeded the cost
of the buildings being protected.
Homework 6 Due
9 April 2004 - Reading Day-No Classes.
Coastal Pollution
A few years ago, a new organism was found in
some estuaries along the east coast: Pfiesteria
piscicida. It killed
fish. It seemed to cause sores
and memory loss in people who handled the dead fish. Where do these
organisms come from? For more see the Pfiesteria web
site.
12 April 2004 - Introduction
to Coastal Pollution
- Pollution: The action of polluting, or condition
of being polluted; defilement; uncleanness or impurity caused
by contamination (physical or moral). spec. The presence
in the environment, or the introduction into it, of products
of human activity which
have harmful or objectionable effects. -Oxford English Dictionary.
- There are
many types of pollution:
- Bacteria and viruses (pathogens),
- Organic compounds (herbicides, pesticides),
- Nutrients (nitrates, phosphates),
- Alien species, such as the European
Green Crab and the aquatic weed Carcinus
maenas on the
US west coast,
- Industrial
chemicals (polychlorinated biphenyls),
- Trash, including plastic rings
used to hold 6-packs of cold drinks.
Pollution has many consequences:
-
It may be concentrated
by marine animals such as shellfish. Eating polluted shellfish causes
illness. Animals at the top of the food chain have the greatest risk.
For information on mercury in fish at the top of the food chain, and
health risks you may wish to read the paper on the subject by the
Center for Science
and Public Policy.
-
It may kill marine life, e.g. birds caught in plastic rings used
to hold 6-packs of cold drinks.
-
Large quantities of nutrients leads to plankton blooms. When the
plants die, they sink to the bottom, decay, and reduce the oxygen
in deeper waters, e.g. the Gulf
of Mexico dead zone caused by Mississippi
River runoff.
14 April 2004 - Sources
of Marine Pollution
- Sources include the following listed in the United States United
States Environmental Protection Agency fact sheets:
- Point
sources such as sewer out falls, oil spills, industrial
discharges; discharge from boats, and dumping of ballast water
from ships (see
the Christian Science Monitor article on
the dangers),
- Non-point
sources such as runoff from farmland in the mid west.
Read this United States Geological Survey fact Sheet on Nitrogen
in the Mississippi Basin-Estimating Sources and Predicting Flux to
the Gulf of Mexico. Non-Point sources include:
- Runoff from farmlands that carry fertilizer, nutrients, pesticides
and herbicides, salts in
irrigation water, and crop residues.
- Runoff from feedlots that carries high concentrations
of nutrients, animal
wastes, manure, and pathogens (bacteria and viruses).
- Runoff from cities that carry heavy metals, organic
chemicals such as oil from highways, fertilizer from
backyards,
and detergent
(the most common pollutant).
- Sand, silt, and clays (sediments)
eroded from land, especially land denuded of plants that
hold sediments.
- Bacteria and nutrients from livestock, pet wastes,
and faulty septic systems.
- Atmospheric deposition of sediments and chemicals
carried by the wind.
- Solvents used to clean boats, anti fowling agents
leached from hulls.
- Trash dumped from ships, dropped
on beaches, and washed into the ocean.
- Fort
Worth maintains a wonderful web site listing sources of urban
pollution, and how the city is reducing the pollution.
16 April 2004 - Alien
Species
18 (Sunday) April 2004 - Quiz 2 at 1:00 PM
This is an open book quiz covering Fisheries and Coastal Erosion.You will have one hour to complete the quiz and email me answers after the quiz has been uploaded to the web.The link above will go active when the quiz is available.
19 April 2004 - Harmful
Algal Blooms
- From time to time, usually in late summer, great masses of single-celled
algae grow in coastal waters. They kill fish. They produce beautiful
displays
of bioluminescence. And, they sometimes lead to death when people
eat shellfish or fish that have concentrated the nerve poisons produced
by
the blooms. To learn more about these blooms, read harmful
algal page produced by the Woods Hole Oceanographic Institution.
Then read Ecology
and Oceanography of Harmful Algal Blooms introduction to harmful
algal blooms. You may also wish to scan some of the information at
the Bigelow
Lab's site. But be warned. If you do, you may never again want
to eat fish.
- Recently Pfeisteria has
been in the news because of its impact on some east coast estuaries.
- To learn more about dinoflagellates,
see the Tree of Life,
then Eukaryotes (organisms
with a cell nucleus), then Alveolates.
Also see The Facinating
World of Dinoflagellates.
21 April 2004 - Oil
Spills and Aftermath
- Overview: The National Academy of Sciences has just published
Oil
in the Sea which summarizes sources of oil pollution:
Nearly
85 percent of the 29 million gallons of petroleum
that enter North American
ocean
waters each year as a result of human activities
comes from land-based runoff, polluted rivers, airplanes,
and small
boats and jet skis,
while less than 8 percent comes from tanker or
pipeline spills
- Oil Spills: Oil spills account for
only a small percentage of oil in the ocean, but large spills attract
much attention. The International
Tanker Owners Pollution Federation Historical
Data has a list of all spills greater than 10 million
gallons. They note that "The average number of large spills per year during
the 1990s was about a third of that witnessed during the 1970s." NOAA
has photographs of the largest
spills.
- Other Information: The Australian
Institute of Petroleum's web site contains useful information
on oil spills, and clean up methods. NOAA has a useful
site for students and teachers with much useful information.
- Effects: Oil spill have an immediate
effect on marine life, and a longer term effect. The International
Tanker Owners Pollution
Federation lists Effects
of Oil Spills.
Read the conclusions of the impact of the Exxon
Valdez oil spill after ten years. NOAA has been monitoring
Prince William Sound, the location of the spill, and they
too have useful results and followup.
23 April 2004 - Policy
Implications
- Federal and state laws in this country have greatly reduced
pollution from point sources. New laws seek to reduce pollution
fro non-point sources. Other countries typically lag behind this
country. See World
Wildlife Fund report on state of Europe's rivers.
- We have learned much from previous oils spills. What can we do
to minimize environmental damage? Sometimes the clean up is worse
than the spill.
The NOAA web site has information on Lessons
Learned from Valdez and Implications.
- Set aside areas that have not been cleaned to compare
with cleaned areas to assess usefulness of cleaning.
- High-pressure, hot-water cleaning causes short-term
and long-term damage.
- Stating that cleanup does "more harm than good" while
to some extent true, is a bit of an oversimplification.
- Any cleanup that changes the physical makeup of the
area delays recovery.
- Oil that penetrates deeply into sand or sediments can
stay fresh for years and be released slowly back
into the water.
Cleanup is
difficult
because it disrupts the physical state of
the area. Recovery is delayed many years.
- Using water to flush away oil may remove fine sediment
needed by organisms.
- NOAA's Damage
Assessment and Restoration pages have examples of case
studies, but in most cases funds collected from those who
spilled toxic
chemicals
were used to restore areas that were not damaged, so it is
very difficult to learn if the damaged areas can or have
been restored
and how. For
example, the Santa
Clara spill of arsenic trioxide seemed to cause no damage.
Most of the material was in drums which were recovered, and
NOAA sampling
could find no arsenic trioxide above background level in
the water, sediments, or organisms. The fines collected
from the spill were
used
to build artificial reefs and to restore salt marshes not
influenced by the spill.
- The Pew Oceans Commission has
published a report on Marine
Pollution in the United States. It lists causes of pollution
and possible ways to reduce pollution.
A new report of the Pew Oceans Commission
released today finds that polluted runoff from farms
and cities - often far inland - went largely unabated or
actually
increased
over the past 30 years, in many cases negating gains
made in controlling direct sources of pollution.
26 April 2004 - Coral Reefs
- Almost all the coral reefs in the world have been degraded by human
activity (See this news
article). The degradation began with the
first fishermen thousands of years ago, and end with the total destruction
of reefs in some areas.
- Begin with NOAA's Coral reef
Information System, especially the
information About
Coral Reefs.
- Read about the coral reefs of the United States at
Coral
Reefs and Associated Ecosystems. International Information
is
provided by ReefBase
- For more information go to the Coral
Reef Web Pages by Teresa Turner
at the University
of the Virgin Islands.
Homework 7 Due
28 April 2004 - Coral Reefs
- Hawaii has many coral reefs.All are degraded from their pristine
conditions that existed before people came to the islands. Some are
slightly degraded,
some are greatly damaged, some are being overgrown by alien species
of algae. Let's learn more about these interesting habitats.
- See this map for their location.
- To learn more about the corals,
begin with this overview
of Hawaiian coral reef ecology from
the Hawaii Coral Reef
Network.
- Many important corals are found in Hawaii,
including the black
coral used in jewelry, the Cauliflower
coral, and the staghorn
coral.
- More information is at the Hawaii Aquarium coral
page.
- The distribution and health of coral reefs in Hawaii are
being assessed by the Hawaii
Coral Reef Assessment and Monitoring Program.
Go to a
few of their study
sites to learn about the reefs.
- To
protect the health of the reefs, many have been included in
marine
protective areas.Go to the site and learn about
the location
of a few
of the areas, and what is allowed and not allowed
in the areas.
- Teachers may wish to go the this education
site for corals and the Reef
Education Network.
- Texas too has coral reefs, far offshore at the Flower
Garden banks. Visit the main
web site for the site.
Here are beautiful
maps
of the seafloor of the west bank. Other maps
show the
east
bank and Stetson
Bank.
- NOAA is exploring the biology of the New England seamounts, especially
the coral community on the seamounts. Learn more about the work,
and download lessons for different grade levels from the Mountains
of the
Sea.
30 April 2004 - Ocean Currents Types
- This begins three days of information about processes in the ocean
that will be useful for teaching oceanography.
- There are many types of currents in the ocean. Most are generated
by the wind. When the wind first starts to blow it creates inertial
currents. After it blows for a few days, it produces Ekman currents.
The variation of Ekman currents in different parts of the ocean
leads to vertical currents that change the internal density structure
of
the upper kilometer of the ocean, leading to geostrophic currents
seen in maps of ocean currents.
- Inertial
Currents are generated by winds suddenly blowing for a
few hours to a day or so. These are the most common currents in the
ocean,
but they have high frequency of about a cycle per day.
- Ekman
currents are generated at the surface of the ocean by steady winds.
- Geostrophic
currents are the currents in the oceans frictionless
interior. These are the currents shown on maps of ocean currents.
OceanWorld has
a simple tutorial on
how winds generate geostrophic currents. Lowell Stott at
the University of Southern California has another
tutorial
that is a little more complicated, and not quite right.
- The Rosenstiel
School of Marine and Atmospheric Science maintains online
maps of ocean geostrophic currents.
- Tidal currents generated by the tides.
3 May 2004 - Ocean Current Measurements
4 May
2004 - Ocean Waves
- Ocean waves are an example of the more general concept
of waves in physics. Often, teaching about ocean waves is a stimulating
way
to
teach the theory of waves in the national and state standards for
teaching science.
- The important types of waves include:
- Surface
waves used by surfers
- Tides
Homework 8 Due
6 May 2004 - FINAL EXAMINATION
from 8:00 AM - 10:00 PM: No final Exam
Revised on:
3 August, 2009
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