13B_1 – Slide 1
Topic 13B:
Ocean Pollution, Part I
Online Lecture:
Pollution
○ Pollution, Concentration, and Dilution
○ The Ocean: A Good Place
or a Bad Place for Our Wastes?
What is Pollution?
○ harmful substance/energy
put in the ocean by humans
13B_1 – Slide 2
WHO definition
– not just “ugly”
– not necessarily a chemical
– not all chemical pollutants are man-made:
can be a natural substance
● Examples: oil, mercury
More Concentrated = More Dangerous
13B_1 – Slide 3
○ even “good” stuff is dangerous if too highly concentrated
e.g., too much Ca: prob’s absorbing nutrients, kidney damage
e.g., Bush & arsenic standards
○ Which glass of salt water is the most “concentrated”?
1 tsp of salt
1 cup of water
A
2 tsp of salt
1 cup of water
B
C
2 tsp of salt
2 cups of water
Is dilution
the solution
to ocean
pollution?
○ opposite of concentrated is dilute
hard to know what “too concentrated” is:
harmful effects can take time to appear
Low concentrations
are more dangerous
in some cases!
2 toxins in safe (“low”) concentrations can become
dangerous when mixed. Some people are like this…
The Ocean: A Good Place for Our Wastes
13B_1 – Slide 4
○ The ocean is good at spreading out our wastes:
– water is the universal solvent (dissolves substances)
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#1
#2 – waves and currents cause water to mix
and carry substances from place to place
#3 – Big: plenty of room to spread out into
e.g., Bikini Islands after 1954: H-bomb tests
• bonds hold
pollutants
together
(concentrated)
• water
molecules
pull the
pollutants
apart
The Ocean: A Bad Place for Our Wastes I
13B_1 – Slide 5
The ocean has limits. It can even re-concentrate wastes.
○ “holding capacity”: can only hold so much
(e.g., water molecules not available to bond)
e.g., acid rain & the atmosphere
○ waves and currents
can bring pollution back to us
○ density differences can keep pollution
at the top or the bottom of the ocean
Submarine Pipe
Seawater
Lab
Where is most life,
near top or bottom?
dense sewage
sludge
The Ocean: A Bad Place for Our Wastes II
13B_1 – Slide 6
○ Bioaccumulation (Biomagnification):
– small organisms have very little toxin in them
– larger animals eat lots of
small organisms, so more & more
toxins build up in their bodies
● the more they eat,
the more toxic they become
● higher up the food chain
= more toxins
Clam
Where are
you in the
food chain?
● fatty tissues absorb
more toxins than other tissues
Humans are unfit to eat according to the FDA.
Clam