Responses to Stress, Toxic, Chemical, and other Pollutants in Aquaric Ecosystems

Who was the first person to bring the effects of pollution to the public’s attention?

Rachel Carson, brought to attention of impairment which have evidence of damage to aquatic life, unsusuitability for drinking production of fish that are not safe to eat or being unsafe for swimming.

Pristine aquatic habitats _______________.

NO longer exists, due to pollutants transported atmospherically on a global scale

Climate change in everywhere and major watersheds are disturbed

There are more than _____ chemicals in commercial use, only about ___ have been screeened for tonxicity only ____ have been screened for Carcinogensis.

72.000, 10% and 2%

Exposure can either be what?

Acute: single late pulse over a short period of time.

Chronic: Low dowses over a long period of time

What are the responses to exposure?

Lethal= death

Non-lethal=not death but affected

Instantaneous or Cumulative

What does LD mean?

Lethal Dose, the 50 represents the amount listed with kill 50% of those exposed

How can toxins be carcinogenic?

If the accumulation causes enough mutations to form cancers.

In the presence of two or more toxins, what interactions may occur

Antagonism: when chemicals cancel each other out

Additive: when both chemicals affect the organism.

Synergistic: when the chemical sum is worse than just the additive effect (one chemical may strengthen the effect of the other)

What is Bioconcentration?

The uptake of the chemical from the surrounding. (Ex: organisms at the lowest level: grass shrimp or plankton with mercury

What is Bioaccumulation?

The uptake of the chemical from the water and food containing the chemical (Shrimp)

What is Biomagnification?

The exponential increase in the accumulation of the chemical from the bottom of food web to the top (Catfish)

What is Bioassesment?

The evolution of the degree of pollution based on diveristy of organism.

What is the EPT index?

Indicator that compares the percentages of Ephemeroptera, Plecoptera, and Trichoptera. (In cleaner waters bc intolerant of pollution)

Individual species may be given a pollution index score then survey id done and the pollution index is based on total score of the survey

What are some of the Pharamaceuticals and Endocrine disrupters in water?

80,000 specific organic pollutants that humans use

They are flushed or pushed through humans (Birth Control)

Antibiotics have become an artificial selection of antibiotic resistant bacteria in the environment.

Even thought antibiotic do nothing for a virus

What are some consequences of radioactive elements for Arsenic in water?

The chemical enters the water stream through rock/ erosion that occurs with arsenic-containing rocks also in mining, industrial discharge and agricultural run-off. Consequences can be severe to organisms and even carcinogenic.

What is salt pollution?

Occur through direct application of salts to roadways, sidewalks, or agricultural and urban runoff, and sewage. Saly for de-icing→ run off into freshwater→ increases salinity

Causes osmotic stress in freshwater organisms

What can be increased through agricultural and urban runoff-offm watershed disturbance (logging) and removal of riparian vegetation and alteration of hydrodynamics regimes?

Turbidity and suspended solids

What is Thermal Pollution?

May either be cooling or heating

Can be causes by industrial effluent, removal of riparian vegetation, runoff or global warming

affect metabolic rates, reproduction or respiration.