Transcript Ocean Pollution - New York State Regents Earth Science

Marine Pollution
For most of human history people relied on the
“Dilution Philosophy”.
This is the mistaken notion that the oceans are so
vast that no matter how much ‘stuff’ we dump into
them, and no matter what that ‘stuff’ might be, the
substances will be so diluted that they will not cause
any harm.
For most of human history, when populations were
small and industrialization had not yet introduced
mass-production, this idea seemed to work.
And of course since no one was looking for the harm
caused by pollution, none was found.
If there was a single turning point it may have been
in June of 1962 when Silent Spring was published
in three parts in The New Yorker magazine. The
book was released in September of the same year.
Silent Spring quickly
became a NY Times
best seller and was
the first widely read
account of damage
to the environment
resulting from human
activity.
Silent Spring documented the effects of the pesticide
DDT on the brown pelican.
Brown Pelican populations had been decreasing
and no one knew why.
Studies revealed that the birds were laying eggs with
paper-thin shells which broke as soon as a bird sat
on them.
Further investigation
revealed extremely
high levels of DDT
in the birds themselves.
It was easy to establish that DDT interfered with
shell production, but what was less obvious was why
there were high levels of DDT in the birds when
ocean water levels of the pesticide were extremely low.
The answer is biomagnification, shown
here with an osprey
at the top of the food
chain. The same
principle applies to
pelicans or any animal,
including humans, at
the top.
But how did the DDT get into the ocean?
Agricultural runoff:
DDT was sprayed on crops
to kill pests and improve
crop yields.
With every rain some of
the chemical was washed
into the ground where it
found its way to streams,
and rivers and eventually to the sea.
Silent Spring was published in 1962. It took 10 years
but eventually the use of the pesticide was banned.
The brown pelican and other fish-eating birds (ospreys
and bald eagles) have made a remarkable comeback.
It is almost certain that there are small amounts of DDT
in your body right now.
How did it get there?
DDT residues in the soil where the plants you eat are
grown.
DDT in the feed of the animals you eat.
DDT in the ground water you drink.
DDT in fish which become fish meal which is added to
animal feed.
But most important, one person can make an enormous
difference.
Thanks to Rachael Carson a great threat to the
environment has been reversed.
Pollution of the marine environment comes in many
forms which have one thing in common: HARM to
the environment.
Forms of ocean pollution include..............
> Garbage dumping
> Acidification
> Eutrophication
> Plastics including nurdles and microbeads
> Noise, aka sound pollution
> Silt and dust from farms, deserts, and construction
> Issues caused by deep sea mining
> Release of methane from clathrates
For almost all of human history garbage has been
dumped into rivers or directly into the sea.
Sometimes it was burned first. Sometimes the raw
garbage was dumped.
New York City provides a case in point:
Until the 1880’s 75% of NYC garbage was dumped
directly into the Atlantic Ocean.
Later some waste was buried in land fills and the rest
was burned in incinerators. The ash was dumped at
sea.
Dumping of garbage and ash creates ‘dead zones’
in the oceans (see red circles on the map).
There is virtually no life in these regions.
Year
Act
Public Law Number
1972
Marine Protection, Research, and Sanctuaries Act
P.L. 92-532
1974
London Dumping Convention Implementation
P.L. 93-254
1977
Authorization of Appropriations
P.L. 95-153
1980
Authorization of Appropriations
P.L. 96-381
1980
Authorization of Appropriations
P.L. 96-572
1982
1986
1986
1987
1988
1988
P.L. 97-424
P.L. 99-272, §§6061-6065
P.L. 99-662, §§211, 728, 1172
P.L. 100-4, §508
P.L. 100-627, Title I
P.L. 100-688, Title I
1990
Surface Transportation Assistance Act
Budget Reconciliation
Water Resources Development Act
Water Quality Act of 1987
Ocean dumping research amendments
Ocean Dumping Ban Act
U.S. Public Vessel Medical Waste Anti-Dumping Act of
1988
Regional marine research centers
1992
National Coastal Monitoring Act
P.L. 102-567, Title V
1992
Water Resources Development Act
P.L. 102-580, §§504-510
1988
P.L. 100-688, Title III
P.L. 101-593, Title III
All of the laws (above) were intended to ban ocean
dumping, provide for monitoring of the environment,
and improving the quality of water.
Much marine pollution
came from the thousands
of ships that cross the
seas each year.
Ships discharge:
Fuel oil
Human wastes
Bilge water, Water from ballast tanks,
Water used to flush out cargo holds and tanks.
Water from ships laundries
Solid wastes from all ship operations
Since there are thousands of ships of all kinds
constantly crossing the seas they account for a
great deal of marine pollution.
Recent laws and
treaties severely
restrict this kind of
pollution, however
some shipping lines circumvent these regulations by
registering their ships in countries that have not
signed the treaties and do not enforce these laws.
Eutrophication: A process in which an ecosystem is
damaged as a result of the introduction of plant
nutrients such as nitrates and/or phosphates.
Most plants need
minerals which they
usually get from the
ground or from the
water.
The most important of the minerals are nitrates and
phosphates.
Usually it is the amount of these minerals available that
limits plant growth.
When farmers fertilize their fields they are adding these
minerals. This increases crop yields.
But sometimes we add these same fertilizing minerals
to bodies of water even though we never intended to.
Sewage discharge contains
large amounts of nitrates from
human waste.
It also contains large
amounts of phosphates
from all the detergents
we use to clean dishes,
laundry, and other
items.
Another major
source of nitrates
and phosphates is
runoff from farms,
golf courses, and
lawns.
Adding fertilizer to bodies
of water causes algae
to grow at a very rapid
rate.
The more algae that
grow, the more algae
die, and when they die
they sink to the bottom
forming a thick layer
of dead plant material.
This is welcome news for
the bacteria in the water
which break down the
plant material in a process
called decay.
Of course more dead plant
material for the bacteria to
‘eat’ means more bacteria.
Since these bacteria are
aerobic they quickly use
up all the oxygen in the
water.
Without dissolved oxygen
in the water the fish, frogs,
insects larvae, and all other
aerobic life forms vanish.
The only thing left is a body of
water covered in a thick layer of
green slime.
Quick recap:
1) Add fertilizer (sewage) to a body of water.
2) More and more algae grow.
3) More algae growing means more algae dying.
4) Dead algae are food for aerobic bacteria living
in the water so soon there are more bacteria.
5) Bacteria deplete the oxygen in the water,
6) With the oxygen gone all the aerobic organisms,
the fish, amphibians, and insect living in the water
die.
7) What’s left is a lifeless, slime covered body of
water.
Plastics:
The problem is simple.....
We dump thousands of tons of plastic in the oceans.
Almost none of it is biodegradable. It lasts forever.
Ocean currents called
gyres concentrate the
floating plastic garbage
into two large areas of
the ocean.
Marine organisms,
including birds, fish,
turtles, and mammals
such as whales and
dolphins eat the
plastic.
Since it cannot be digested it clogs their digestive
systems leading to slow death by starvation or worse,
slow and painful death due to intestinal blockage.
Above, the rotting carcass of a pelican reveals what
killed it: A lighter, a plastic bottle cap, a prescription
pill vial and other assorted bits and pieces.
Many plastics release chemical into the water. Some
of these are toxic while others don’t kill directly but
interfere with the reproductive cycles of marine
organisms.
Much attention has been given to BHA, a chemical
now banned from use in food containers in the US
and in Europe.
Still, millions of tons of plastics containing BHA are
already in the oceans and are releasing the
chemical into the water.
The two primary sources of plastics are ocean
dumping of municipal waste (from cities) and
dumping from ships.
As usual, attempts to regulate both sources by
laws and treaties are limited because so many
countries fail to sign treaties or to enforce laws.
In recent years many
products have been
made with plastic
micro beads which
act as abrasives to
smooth skin.
More and more of these
particles have been
appearing in the Great
Lakes and will make
their way to the oceans.
The micro beads create two
problems................
First, they enter the food chain
and interfere with normal
digestion.
Second, toxic chemicals in the water adhere to the
surface of the beads. When the beads are ingested
by marine organisms the toxins enter their bodies.
In other words, the beads become a delivery system
to get toxins into marine life.
Some manufactures have already agreed to stop
using the beads in their products.
Anthropogenic Ocean Noise Pollution:
‘Anthropogenic’: Man-made
‘Noise Pollution’: Sounds which cause harm
Sources of noise pollution:
 Low frequency active sonar used for echo-location
or locating other ships.
 Seismic surveys using air gun arrays (similar to
sonar but much more intense).
 Noise from ship propellers and on-board machinery.
 Noise from drilling platforms
What harm is caused by noise pollution?
1) Many marine creatures use echo location to find
food. Loud underwater noises interfere with
normal feeding.
2) Noise may drive fish and other species away
from places where food is abundant to other,
less desirable feeding grounds.
3) Studies have documented hearing loss in many
species of fish.
4) Some marine organisms use sound to attract
mates. Noise can interfere with normal reproductive
activities.
5) Fish, frightened by alien noises, have shown
symptoms including..................................
Mutated offspring
Internal hemorrhaging
Higher mortality rates
Stranding (beachings) of whales and dolphins
There will be two bonus questions
on the test based on the following
3 slides.
Oil pollution from spills, runoff from the land, and
from ships at sea.
The two best known oil spills are the Exxon Valdez
spill in March of 1989
and the BP spill in the
Gulf of Mexico in 2010
But there have been many other catastrophic oil
spills. Here are just a few.
1) The Torrey Canyon Oil Spill, March 18, 1967
Where: Scilly Isles, UK
Amount spilled: 25-36 million gallons
2) The Sea Star Oil Spill, Dec. 19, 1972
Where: Gulf of Oman
Amount spilled: 35.3 million gallons
3) Arabian Gulf/Kuwait, Jan. 19, 1991
Where: Persian Gulf, Kuwait
Amount spilled: 380-520 million gallons
Intentional – spilled by Iraq forces to prevent
American troops from landing in Kuwait.
4) Atlantic Empress Oil Spill, July 19, 1979
Where: Off the coast of Trinidad and Tobago
Amount spilled: 90 million gallons
5) Ixtoc 1 Oil Spill, June 3, 1979
Where: Bay of Campeche off Ciudad del
Carmen, Mexico
Amount spilled: 140 million gallons