Download 2017Human Impact

Chapter 17 &18
Human Impact on Oceans
Human Impact
• Pollution – anything introduced into the
environment by humans that is harmful
– Chemicals, trash, noise, heat, sewage, etc.
• Biodegradable – can be broken down by bacteria
reasonably quickly. (paper)
• Nonbiodegradable – can not be broken down by
bacteria (plastic) in a reasonable amount of time.
• Persistent – remains in the environment
permanently.
Persistent Pollutants: Heavy Metals
• High molecular weight elements that can
cause damage to organisms in small
concentrations
• Causes brain, kidney, and liver damage
and birth defects in people
• Examples:
–Mercury, Cadmium, Nickel, Lead, Zinc,
Copper, Chromium
Persistent Pollutants: Mercury
• Sources: incineration of mercury containing
waste (hospital waste, mercury lamps, metal
recycling smelters, coal power plants (#1)),
dental wastewater (fillings), Caribbean folk
medicine, gold mining
• Most harmful when in form of methyl mercury
(converted by bacteria) [CH3Hg]+
http://www.chicagotribune.com/news/chi-mercury-htmlpage,0,6027124.htmlpage
Disposal sites
Persistent Pollutants: Pesticides
• Enter oceans: wind, runoff
– Farmers spray crops
– It can blow in
– It can be washed in by rain
• Created to kill life
• Can affect reproduction and growth of
marine organisms
Persistent Pollutants: DDT
dichloro-diphenyl-trichloroethane
•
•
•
•
Pesticide to kill mosquitoes
Killed many birds and fish
Is currently banned in the US
Used in third world countries where
diseases like malaria are prevalent
Biological Amplification
/Biomagnification
• Persistent chemicals do not break down
• Organisms absorb or digest pollutants
• Pollutants accumulate in top predators
• Phytoplankton
absorb mercury
• Shrimp eat
thousands of
phytoplankton
• Small fish eats
hundreds of these
shrimp
• Large tuna eats
thousands of these
fish
• This is why
pregnant women
shouldn’t eat too
much fish
Oil Spills: Sources of Oil in Ocean
Water
• Enters oceans naturally through seeps
• Enters unnaturally through tanker spills,
pipeline blowouts, leaks on rigs, runoff
from land
• http://www.huffingtonpost.com/news/bp-oil-spill
Millions of gallons of oil into the
environment each year.
Effects of Oil on Marine Life
• Can be ingested through food
– Interferes with reproduction, development,
and growth
– Young are most affected
• Birds and Mammals
– Can get trapped in fur or feathers
– Inhibits ability to stay warm or to fly
– http://www.huffingtonpost.com/2010/12/07/athabascatar-sands-oil-pipeline_n_793389.html#s201084
Oil Spill Clean-Up Efforts
• Fencing Off
– Use fire-retardant booms to contain oil
• Skimmers
– Scrape oil off of surface of water
• Dispersants
– Chemicals that break oil into small droplets
– Dispersants can be toxic
• Hot or Cold Water Washing
– To remove oil from rocky shorelines
– Hot water can be harmful to microorganisms
• Bioremediation
– Use of engineered bacteria to detect and
break down oil
The 2010 Gulf of
Mexico Oil Spill
• The explosion of the Deepwater Horizon rig on
April 20, 2010 killed 11 people and led to the
BP oil spill
– the largest in U.S. history and second-largest in
world history, 205.8 million gallons spilled
– Oil flowed from the seafloor for 3 months before
being capped on July 15th, 2010
Oil Spill Activity
• 1) Watch the film
“Scientists and the Alaska
Oil Spill” and read the
article “Exxon Valdez oil
spill anniversary.”
• 2) Make a t-chart that
shows the main points
presented in each.
• 3) Write a couple of
sentences: Who do you
believe and why?
Exxon
Defenders
Endangered Species
• Extinction of marine animals can be
caused by
–Overfishing/overhunting
–Habitat destruction
–Pollution
–Competition with alien species
– http://www.huffingtonpost.com/2010/03/30/13
-endangered-animals-of_n_513650.html#s75962
Overfishing
• High capacity fishing nets and lines have
greatly increased the amount of fish being
taken from the sea (trawl nets, long-lines)
• Ghost fishing – abandoned fishing gear kills
millions of fish a year
• By-catch – fish not of the targeted species that
are caught are often dumped overboard after
they have die in the nets.
Sustainable Seafood
• Fisheries harvests should be managed so as to
ensure long-term presence of fish stocks.
• Aquaculture – fish farming can be a solution
to overfishing.
– Fish farms can cause pollution ( fish waste,
antibiotics, chemicals, pesticides)
– Farmed fish are often fed wild caught fish
Whaling: Hunting of Whales
• Led to all whales being endangered
• 1994 many countries banned whaling in
Antarctica
– Except: Norway and Japan
• Started hunting dolphins instead
Habitat Destruction
• Estuaries
– Dredged for ships
– Filled in for building on
– 1/3 of estuaries have disappeared in the
US
• Mangroves
– Similar to estuaries
– Also cut for timber and fuel
Habitat Loss:
coral bleaching
• Coral bleaching refers to a process in which corals expel
their algal cells (zooxanthellae)
• Bleached coral looks like dead coral except polyps are
still present.
• Coral bleaching can be caused by stressful
environmental conditions such as extreme temperature,
low salinity, extreme light and various toxins.
• More recently, coral reefs are showing early signs of
stress due to global warming caused by green house gas
emissions.
affect of humans
on coral survival
• Coral reefs have also suffered significant damage from
over-fishing and run-off from agricultural land.
• The number of people living close to the reefs is the
main factor causing declines in coral reefs.
• In the Caribbean alone, reef losses are endangering a
large number of species, from corals to sharks.
• It is estimated reefs provide $4 billion in ecosystem
services - quantifiable benefits including fishing, tourism
and protecting the coast from storms
Alien Species
• Any species that is not native to the environment
• Harmful for several reasons:
– May carry parasites
– No natural predator
– Compete with natives for resources
• Enter other oceans through ballast water
– (Water holds in cargo ships)
– Marine Invasive Species Pictures
Battling Invasive Species
“Climate is what we expect; weather is what we get.” –Mark Twain
Climate Change
• AKA global warming
• Climate = pattern of atmospheric conditions
across large geographic regions over long periods
of time (seasons, years, millennia)
• Climate change refers a the shift in global climate
that has recently been observed.
– (change in annual rainfall, temperatures, and severe weather
patterns)
– Climate changes naturally, and always has, but the recent
rapid warming of the planet and its change in atmospheric
composition are widely influenced by human activities.
Greenhouse effect
• Earth’s temperature depends on how much of
the sun’s radiation enters the atmosphere and
how much escapes back into space.
• Greenhouse gasses (carbon dioxide, water
vapor, methane, and CFCs) trap sunlight that
normally reflects back into space. This
increases the temperature of our planet
(global warming).
Greenhouse effect
Blue Line =
Average Global
Temperature
Red Line =
Atmospheric
CO2
Manmade causes of climate
change
Increase in carbon dioxide due to:
Burning of fossil fuels: We remove carbon-rich
fuels from the ground where they have been
stored for millions of years, and combust them in
an instant, sending CO2 into the atmosphere.
Deforestation: Cutting down trees, removing
vegetation from the land, decreases the sink for
carbon.
U.S.
186.1
Total CO2 emissions
European
Union
Between 1950-2001 in billions of
tons
127.8
Russia
68.4
Ukraine
21.7
China
Poland
Canada
14.4
14.9
Kazakhstan
57.6
10.1
Japan
31.2
India
Mexico
15.5
7.8
Kuwait
Trinidad and
Tobago
Australia
South Africa
8.5
US:
United
Arab
Emirat
es
7.6
4% of world’s total population
25% of the world’s greenhouse gases
China:25% of the world’s population
TIME magazine, 2001
8.5% of the world’s greenhouse gases (since 1950)
http://www.dailymail.co.uk/sciencetech/artic
le-2779286/Now-s-GLOBAL-warmingInteractive-map-reveals-countries-emitcarbon-dioxide-160-years.html
China emits the most CO2 as a
whole.
The US still emits more CO2 per
person than any other country.
Why is climate change a problem?
• Economic losses due to weather and storms rose 10fold over the past 40 years, partly due to climate
change.
• Temperature will rise 3–5°C (5–9°F).
• Temperature extremes will cause health problems;
tropical diseases will move north into the U.S.
• Sea level rise will flood coastal wetlands, real estate.
• Ecosystems will be altered; some will disappear.
• Agriculture and forestry will be forced to adjust to
the shifting climate.
• Increasing CO2 decreases the pH of seawater (more
acidic).
Sea Level Rise
• Melting of
– Greenland Ice Sheet
– Antarctic Ice Sheet
– Glaciers and ice caps
• Expansion of heated (warm) sea water
2 - 4 C warming by ~2100
 0.18 - 0.59 meter rise in sea level
IPCC (2007)
Arctic Sea Ice (in September)
2005
Asia
Russia
Canada
Europe
U.S.A.
data from National Snow and Ice Data Center (Boulder, CO, USA)
Arctic Sea Ice (in September)
2005
sea ice edge,
where normally found
5.6
million km2
data from National Snow and Ice Data Center (Boulder, CO, USA)
Arctic Sea Ice (in September)
2007
2005
4.3
5.6
million km2
million km2
sea ice edge (where normally found)
data from National Snow and Ice Data Center (Boulder, CO, USA)
Arctic Sea Ice (in September)
Size (million km2)
9
8
7
6
2005
5
2007
4
‘78
‘82
‘86
‘90
‘94
‘98
‘02
‘06
Year
data from National Snow and Ice Data Center (Boulder, CO, USA)
Greenland Ice Sheet
Melting ice sheets  Sea level rise
How it gets worse before it gets
better…
• Arctic ice usually reflects light back into space.
• When Ice melts more light is absorbed by the
Earth. – Positive feedback loop
20-big-uscities-thatshouldworryabout-sealevel-rise
•
(The paper, "Implications of Recent Sea Level Rise Science for Low-Elevation Areas in Coastal Cities of
the Conterminous U.S.A.," published Climatic Change Letters.)
• Rising sea levels will likely inundate 9 percent of the land within 180
American cities by the end of the century. This is on the low end of
the best estimates current science has to offer.
Sea Level Rise
1-5 meters in Bangladesh
PCC slide no.
7-8 meters in Florida
Carbon dioxide acidifies seawater
CO2
Atmosphere
CO2
Ocean
“shelled-critters”
• Dissolved CO2 reacts with water to form
carbonic acid.
• Carbonic acid can dissolve carbonate
(which plankton, crustaceans, and
molluscs use to make shells).
• The ocean is already more acidic than it
was 50 years ago.
Source: Alfred-Wegener-Institute
SEM photograph of E. hux
Two venues for action
POLICY REFORM
PERSONAL GHG CUTS
• Drive less
- Carpool or use transit
- Walk or bicycle
- Combine errands
- Telecommute
• Drive a fuel-efficient car
• Reduce home energy use
- CFLs
- Energy Star appliances
- Heat room-by-room
- Minimize summer A/C
• Purchase GHG offsets
PCC slide no.
• Vote
• Financially support
concerned organizations
• Volunteer for concerned
organizations
- Door-to-door education
- Legislative lobbying
Ocean Pollution:
Spreading the word
• 1) Form groups of 2.
• 2) Using what you have learned and the article
“Developing Solutions and Spreading the
Word” create a poster that advertises the
dangers of marine pollution and what we can
do about it in a fun and creative way.
• 3) The team with the best poster at the end of
class gets CANDY!!!
Human Impact Poster
• Make a colorful poster that will educate the
student body about environmental issues
concerning the ocean. Use any of the
following topics.
• Oil Spills, mercury pollution, light pollution,
overfishing, whaling, sea level rise, climate
change, ocean acidification