Transcript 16.3 Water Quality

16.3 Water Quality
KEY CONCEPT
Pollution of Earth’s freshwater supply threatens
habitat and health.
16.3 Water Quality
Water pollution affects ecosystems.
• Pollution can put entire freshwater ecosystems at risk.
• Did you know that only some parts of medicine get used
by the body, and the rest is waste?
– hormones: male fish show female characteristics
– decreases species populations
– toxins accumulate up the food chain
16.3 Water Quality
Water pollution affects ecosystems
Runoff from farms contain fertilizers
that stimulate plant and algae growth.
Plant and algae growth will rob the
aquatic environment of oxygen that
may lead to the dying off of fish
populations.
16.3 Water Quality
• Scientists determine the health of an ecosystem using
indicator species.
• Indicator species provide a sign of an ecosystem’s health.
 Amphibians - Frogs are an
indicator species because
the skin of tadpoles and
adults is water-permeable.
Frogs come into direct
contact with pollutants that
can cause deformities
such as extra arms, legs,
and body tumors.
16.3 Water Quality
Biomagnification causes accumulation of toxins in the
food chain.
• Some pollutants are Fat-soluble.
• These chemicals are stored in the body and passed up
the food chain.
• This process is called biomagnification.
16.3 Water Quality
Foster’s Tern provides scientists clues about the
pollution in the San Francisco Bay.
• This indicator species
is a top predator
• The main part of the
Foster’s Terns diet is
fish.
• Scientists find large
amounts of chemicals
contaminants
(mercury and PCB’s)
in the tissue of dead
chicks
16.3 Water Quality
Biomagnification causes accumulation of toxins in the
food chain.
• Pollutants can move up the
food chain.
– predators eat contaminated
prey
– pollution accumulates at
each stage of the food chain
• Top consumers, including
humans, are most affected.