Water 5

1. Water Chemistry andWater Chemistry and
PollutionPollution

2. EutrophicationEutrophication
 Excessive Nutrients: N>3ppm P>.01ppmExcessive Nutrients: N>3ppm P>.01ppm
 Causes excessive growth of marineCauses excessive growth of marine
autotrophs (large algal blooms)autotrophs (large algal blooms)
 Die off of Marine Plants = Lack of LightDie off of Marine Plants = Lack of Light
 Decomposition of marine plants usesDecomposition of marine plants uses
more oxygen which can lead to anmore oxygen which can lead to an
“oxygen sag” in an aquatic environment“oxygen sag” in an aquatic environment

3. Dissolved OxygenDissolved Oxygen
 DO is dependent on aDO is dependent on a
number of factorsnumber of factors
including salinity,including salinity,
temperature,temperature,
photosynthesis ratesphotosynthesis rates
atmosphericatmospheric
pressure, and thepressure, and the
amount of wind &amount of wind &
wave turbulence.wave turbulence.
 The suitability of a bodyThe suitability of a body
of water for organisms toof water for organisms to
live can be determined bylive can be determined by
the amount of DO in thethe amount of DO in the
water.water.
 Fish require 4-5 mgFish require 4-5 mg
OO22/liter of water while air/liter of water while air
breathing aquaticbreathing aquatic
organisms require less.organisms require less.

4. Nitrates/NitritesNitrates/Nitrites
 EPA standards: NitrateEPA standards: Nitrate
cannot exceed 10 mg/Lcannot exceed 10 mg/L
 Excess levels of nitratesExcess levels of nitrates
can cause hypoxia.can cause hypoxia.
 Excess nitrite can causeExcess nitrite can cause
the “blue baby syndrome”the “blue baby syndrome”
and is toxic to warm-and is toxic to warm-
blooded organisms.blooded organisms.
 Natural levels of nitratesNatural levels of nitrates
in surface water isin surface water is
<1mg/L.<1mg/L.
 Essential nutrient forEssential nutrient for
plants & animals.plants & animals.
 Sources of nitrates comeSources of nitrates come
from the atmospherefrom the atmosphere
(automobile exhaust),(automobile exhaust),
fertilizer runoff from land,fertilizer runoff from land,
animal excrement,animal excrement,
sewage wastes, and plantsewage wastes, and plant
debris.debris.
 Wastewater treatmentWastewater treatment
plants can have nitrateplants can have nitrate
levels as high as 30mg/L.levels as high as 30mg/L.

5. PhosphatesPhosphates
 Phosphorus is also an essential nutrient for the plantsPhosphorus is also an essential nutrient for the plants
and animals that make up the aquatic food web.and animals that make up the aquatic food web.
 Phosphorus is naturally available in low concentrationsPhosphorus is naturally available in low concentrations
and is often limited.and is often limited.
 Small increases can result in accelerated plant growth,Small increases can result in accelerated plant growth,
algae blooms, low dissolved oxygen, and the death ofalgae blooms, low dissolved oxygen, and the death of
certain fish, and other aquatic animals.certain fish, and other aquatic animals.
 Sources of phosphorus includeSources of phosphorus include soil and rocks,soil and rocks,
wastewater treatment, fertilizer runoff, failing septicwastewater treatment, fertilizer runoff, failing septic
systems, runoff from animal manure, disturbed landsystems, runoff from animal manure, disturbed land
areas, drained wetlands, and commercial cleaningareas, drained wetlands, and commercial cleaning
preparations.preparations.

6. Why are we concerned aboutWhy are we concerned about
ocean pollution?ocean pollution?
 TransportationTransportation
 Coastal ocean is used most heavily-76%Coastal ocean is used most heavily-76%
of fisheries!!of fisheries!!
 recreation- jet skis, cruise shipsrecreation- jet skis, cruise ships

7. CausesCauses
 Natural (not all are human-caused)Natural (not all are human-caused)
 Volcanoes- atmospheric pollutants (ash, SOVolcanoes- atmospheric pollutants (ash, SO22))

Underwater seepsUnderwater seeps
 AnthropogenicAnthropogenic

Anthro=humansAnthro=humans

Industry, mining, agriculture, transportationIndustry, mining, agriculture, transportation

RecreationRecreation

8. 4 main pollutants4 main pollutants
 Petroleum-least damaging, can be brokenPetroleum-least damaging, can be broken
down naturallydown naturally
 Sewage sludge-water treatment does notSewage sludge-water treatment does not
treat for chemicals, only treats wastetreat for chemicals, only treats waste
 Toxic chemicalsToxic chemicals

DDT (banned), PCB’s, PAH’sDDT (banned), PCB’s, PAH’s

Still in environment todayStill in environment today
 Heavy metalsHeavy metals

Lead, mercury, methylmercuryLead, mercury, methylmercury