Transcript Environmental Issues for the Marine Biome

Environmental Issues
for the Marine Biome
Essential Questions
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How are humans impacting the marine
biome?
What is our role in protecting the marine
biome?
How are humans impacting
the marine biome?
One Ocean: The Changing Sea
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http://oneocean.cbc.ca/series/episodes/4the-changing-sea
Questions provided
 45:15 mins
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The 5 issues facing the Marine Biome
Acidification
 Coral Depletion
 Deadzones
 Overfishing
 Pollution
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What is Acidification
An increase in the pH level of the water of
an ocean.
 The increase in pH is attributed to an
increase in carbon
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Carbon interacts with other ions in the water
to produce carbonic acid
The pH scale
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A scale which measures
from 0 to 14
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7 = neutral = pure water
0.8 = acidic = battery acid
Typically the ocean ranges
from 7.9 to 8.2 pH
Acid Test: The Global Challenge of
Ocean Acidification
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http://www.nrdc.org/oceans/acidification/
aboutthefilm.asp
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21:34mins
What causes Acidification
Use of fossil fuels
 Dependence on fertilizers
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We are dumping carbon dioxide into the
atmosphere at a rate of 28 million metric
tons per year
What is the result of Acidification?
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The more acidic the water, the less ability it has
to absorb CO2
Fish are starved for oxygen
Corals and other marine species are deprived of
calcium
A proliferation of deadzones
Ocean acidification (OA) is the quiet tsunami of
environmental degradation.
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Within a few decades, OA may devastate some marine
ecosystems and threaten the productivity of our
fisheries.
What is Coral Depletion?
When the tiny organisms called coral die,
they leave behind a skeleton in the form
of bleached coral. As a bleached area
spreads, the diversity of life in the
immediate area decreases, effectively
turning the skeletal remains of coral into a
marine cemetery.
 ¼ of coral reefs are dead
 60% of coral reefs are in trouble
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One Ocean: Footprints in the Sand
Chp. 2
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http://oneocean.cbc.ca/series/episodes/2footprints-in-the-sand
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10mins
What causes Coral Depletion?
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Rising temperatures
Increased CO2
Increased acidity
Development of
tourism resorts
Sediment
Debris
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Chemical pollutants,
fertilizers, pesticides
Overfishing
Bottom trawling
fishing
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A single pass of a trawl
removes up to 20% of
the seafloor flora and
fauna
Coral mining
Causes of Coral Depletion
There is a lack of carbonate ions for corals
to grow
 There is a lack of zooxanthellae which
protect and feed corals
 Algal blooms smother the corals
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What is the result of Coral Depletion?
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¼ of all fish spend some part of their life on a
reef
May loose these ecosystems in 20-30 years
Fish and other sea life found in coral reefs feed
between 30 million and 40 million people
annually – providing jobs
Coral reefs also form barriers around coastlines,
protecting coasts (and the residences and
business found there) from erosion caused by
waves and currents.
What are Deadzones?
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are areas where the bottom water (the water at
the sea floor) is anoxic — meaning that it has
very low (or completely zero) concentrations of
dissolved oxygen
An area of the ocean devoid of life
40 years ago there were <50 deadzones,
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2003 there were 146
2008 there were 405!
2010 there were 415!
Some are as small as a square kilometre
(0.4 mi²), but the largest dead zone covers
70,000 square kilometres (27,000 mi²)
What causes Deadzones?
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Human causes:
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Use of fertilizers
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Nitrogen
Phosphorous
Runoff from sewage
Urban land use
Can occur naturally in enclosed bodies of water or
as a result of coastal upwellings and reduced
winds and currents
Nitrogen and phosphorous causes the increase
reproduction of phytoplankton
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The result is algal blooms
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Blooms gobble up available oxygen as they spread
When the blooms die, they sink to the bottom, as they
decompose (by bacteria) they further deplete the oxygen
Location of Deadzones
What is the result of Deadzones?
Bottom-dwelling species often die
 Reproductive problems in fish involving
decreased size of reproductive organs, low
egg counts and lack of spawning
 Fish are often quickly rendered
unconscious and doomed
 Reports of baby octopuses climbing up
crab-trap ropes in order to get air
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What is Overfishing?
the harvesting a fish species at a rate
exceeding the maximum harvest that
would still allow the population to be
replaced by reproduction
 70% of the world’s fisheries are now fully
exploited
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What causes Overfishing?
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Use of long-lines
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With 60 miles of hooks
Bottom trawling
 Bycatch
 Illegal fishing
 Consumer demand
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Bottom Trawling
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Bottom trawlers drag giant weighted nets along
the ocean floor, ripping up or scooping out
whatever they encounter, including ancient coral
forests, gardens of anemones and entire fields of
sea sponges.
Seamounts -- volcanic mountains and hills that
rise from the ocean floor but do not break the
surface -- are being damaged by these industrial
fishing practices, and the wealth of flora and
fauna clustered around sea mounts is being
wiped out in the process.
Bottom Trawling continued
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Many rare, ancient and even unknown species -some of which hold promise for biomedical
research or are critical to undersea biodiversity -are at risk, including:
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Cold-water corals, which are as exotic and colorful as
their warm-water counterparts.
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Sponges
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Red tree corals form ancient forests, stretching up to 7 feet
tall and 25 feet wide, providing shelter for fish, shellfish,
and sea stars.
Corals on seamounts can live up to 8,000 years and tend to
take branching, tree-like forms, making them particularly
susceptible to trawl damage.
form giant fields in the deep, creating stretches of habitat
up to a mile long and 50 feet high.
Fish
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including orange roughy, which take decades to mature and
can live for 125 years.
Bottom Trawling continued
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New species of flora and fauna tucked away on
seamounts and other deep-sea habitats.
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Just like the creatures of the Galapagos Islands,
many seamount species have evolved in isolation,
resulting in unique species.
Scientists studying a cluster of seamounts near New
Caledonia have determined that nearly one-third of
the species there have never been seen anywhere
else.
Novel chemical compounds that hold promise
for the treatment of cancer and other diseases
after their discovery by scientists investigating
the biomedical properties of deep-sea
organisms.
By-Catch
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Unwanted and undersized fish hauled up
by bottom trawlers are thrown back dead
or dying -- in some areas, as many as four
pounds of fish are discarded for every one
pound brought to market.
What is the result of Overfishing?
If we don’t stop overfishing, all of the
planet’s fish will have been caught by
2048
 A chain reaction occurs when we overfish
a particular species which can decimate
other fish species and even an entire
ecosystem
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What is Pollution?
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Every 2.59 square kilometers of the global
ocean contains an estimated 46,000
pieces of floating plastic
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Farm and yard fertilizer runoff, sewage,
and other land-based sources that
contributes to harmful blooms of algae,
which in turn lead to fish kills and
swimmer illness, and ocean deadzones
What causes Pollution?
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Discarded plastic bags, six pack rings and other forms of
plastic waste
Fishing nets, usually made of plastic, can be left or lost in
the ocean by fishermen
Toxic additives used in the manufacture of plastic materials
can leach out into their surroundings when exposed to
water
Heavy metals are metallic chemical elements that have a
relatively high density and are toxic or poisonous at low
concentrations
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Examples are mercury, lead, nickel, arsenic and cadmium
Oil spills – accidental, leaks, explosions
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It is estimated that approximately 706 million gallons of waste
oil enter the ocean every year, with over half coming from land
drainage and waste disposal
Tracking the BP Oil Spill
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http://www.nytimes.com/interactive/2010
/05/01/us/20100501-oil-spill-tracker.html
What is the result of Pollution?
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Plastic
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Fishing nets
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fish, dolphins, sea turtles, sharks, dugongs, crocodiles, seabirds,
crabs, and other creatures, restricting movement, causing starvation,
laceration and infection, and, in those that need to return to the
surface to breathe, suffocation
Plastic Additives
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Aquatic life can be threatened through entanglement, suffocation, and
ingestion.
Some plastic additives are known to disrupt the endocrine system
when consumed, others can suppress the immune system or decrease
reproductive rates
Oil Spills
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If oil waste reaches the shoreline or coast, it interacts with sediments
such as beach sand and gravel, rocks and boulders, vegetation, and
terrestrial habitats of both wildlife and humans, causing erosion as
well as contamination
Immediate effects include mass mortality and contamination of fish
and other food species
Long term effects include poisons the sensitive marine and coastal
organic substrate, interrupting the food chain on which fish and sea
creatures depend, and on which their reproductive success is based
The North Atlantic Garbage Patch
is an area of marine debris found floating
within the North Atlantic Gyre
 estimated to be hundreds of kilometers
across in size, with a density of over
200,000 pieces of debris per square
kilometer
 area shifts by as much as 1,600 km north
and south on a seasonal basis
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The North Pacific Garbage Patch
is an area of marine debris found floating
within the central North Pacific Ocean
located roughly between 135° to 155°W
and 35° to 42°N
 estimates ranging from an area the size of
the state of Texas to one larger than the
continental United States
 high concentrations of pelagic plastics,
chemical sludge, and other debris that
have been trapped by the currents of the
North Pacific Gyre
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The North Pacific Garbage Patch
continued
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In samples taken in 1999, the mass of plastic
exceeded that of zooplankton (the dominant
animal life in the area) by a factor of six
Ninety percent plastic, this debris accumulates on
the beaches of Midway where it becomes a
hazard to the bird population of the island.
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Midway Atoll is home to two-thirds (1.5 million) of the
global population of Laysan Albatross.
Nearly all of these albatross have plastic in their
digestive system and one-third of their chicks die.
An Ocean's Memory
The Endless Voyage Series

http://learning.aliant.net/Player/ALC_Play
er.asp?ProgID=INT_ENDVOY12
Answer the Self-test questions after the
video
 27mins
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What is our role in
protecting the marine biome?