Transcript Ecotoxicology - Coastal Carolina University

Ecotoxicology
You are what you eat!
Where is Pollution?
• Most near the coast…
• 76% of fish harvested
come from the coast
Pfiesteria
• Found in waters high in
nutrients
• Pfiesteria is
microscopic algae
that is a natural part of
the environment
• Harmful Algal Bloom
(HABs)
RED TIDE
• During intense algal blooms, dangerous
levels of toxins are released into the water.
These toxins kill fish (millions of fish may
die in a red tide) and accumulate in the
fatty tissues of shellfish. Humans and
other animals that eat contaminated
shellfish may become paralyzed or even
die.
anthropogenic
• Human- caused pollutants
– Population growth in many urban
areas
– New materials and new
procedures →new and often
dangerous chemicals
Coliform Bacteria
• EPA standards: One coliform colony / 100 mL of water
is cause for concern
• Four colonies per 100 mL requires direct action
• The appearance of coliform bacteria indicates the
presence of raw sewage.
• Raw sewage may contain disease-producing bacteria.
• Coliform is an indicator species.
• A coliform test measures the amount of E. coli present
in the water supply
oil
•
•
•
•
Exxon
Poison to animals
Gets into sediments
Takes about 10 years to fully
clean up
• Least damaging pollutant b/c it gets broken down
by microorganisms
Sewage
• Viruses and bacteria if untreated
• Boston Harbor treatment project… backed up, raw
sewage in drinking water!
DDT
• Pesticides 1940-1970’s
• Dichloro-Diphenyl-Trichloroethane
• Breaks down slow… still around
TODAY!
• Prohibits Ca+ uptake…birds break
eggs when they sit on them
PCB
• Liquid coolant, insulation
• Polychlorinated Biphenyls
• Liver cancer, genetic mutations, reproductive
problems
Lead
• Paint
• Mental retardation
Mercury
•
•
•
•
Batteries, electronics, medical products
Does not affect humans (does effect animals)
Different forms: elemental, inorganic
Bacteria can change Mercury into Methylmercury
(bad for us)
Methylmercury
•
•
•
•
•
Absorbs easily into tissue
Poisonous!!!
Eliminated very slowly
Concentrated in shells and fingernails
Blindness, slurred speech, reproductive
failure
• Passed from pregnant mom to babyneurological problems
• 375,000 babies born each year affected
Plant Toxins
• Ciguatera Poisoning
• Toxin= icthyosarcotoxin
• Originates from the blue green algae in the
food chain of the fish
• Fish known to carry ciguatoxins
– Barracuda
– Black grouper
– King mackerel
• Sensory reversal…
Bioaccumulation
• Bioaccumulation: build-up in concentration of
something with each step of the food chain
– Crosses the blood/brain barrier and placenta
– Eliminated from living tissue very slowly
– Is contained in fish flesh and is not reduced or
removed by cleaning, trimming or cooking
• Bioconcentration: comparison between
creature’s concentration and concentration in
environment (i.e. seawater)