4.4 water pollution

Question 1

define water pollution?

Answer 1

the co ntamination of bodies of water by pollutant either directly or indirectly

Question 2

give three examples of natural pollution sources?

Answer 2

volcano erruptions

algae blooms

Invasive species e.g cane toad

Question 3

outline what is meant by the term anthropogenic pollutant?

Answer 3

created by human acivities

Question 4

what are the two caatgories we can devide pollutants in?

Answer 4

organic and non-organic

Question 5

give some examples of orgnaic pollutants and their effects?

Answer 5

pathogens- disease
human+animal waste- smell
biological detergants- euthrophication

Question 6

what are some examples of inorganic pollutants and what are their effects?

Answer 6

heavy toxic metals- bioaccumilation
phosfastes- eutrophication
noise- disrupts marine life

Question 7

list three sources of fresh water pollution and three sources of marine pollution?

Answer 7

FRESHWATER-
agricultuaal run off
swage
indrustrial discashrge
solid domestic waste

MARINE WATER-
rivers
pipe lines
the atmosphere
human acitivites at sea
oil spills

Question 8

describe what is meant by the term Biochemical oxegen demand (BOD)

Answer 8

a measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity by microorganisms.

Question 9

describe what is meant by the term biotic index?

Answer 9

a biotic index indriccetly messurs pollusion by assesing the impact on species within the community according to their tolerance, divserity and relative abunance.

Question 10

outline how indicator species can be used to asses leaves of pollutant in water?

Answer 10

diffrent spcies have diffrent tolerance to enviromenal condiditions and change. The presence or absence, heath of these indicator species can be used to suggest the condition of the enviroment.

e.g certain lichen scpies indicate leaves of sulphere dioxide in air.

red alge inhibit saline rock pods and are absent from brackish ponds.

Question 11

you have a drawing of a river, there is an organic pollutant at point X, and point A is above the stream of point X, what may you find here in terms of indicator invertebrates?

Answer 11

at this site there will be no organic pollutant. The invertibates found here will be pollutant intolerantsuch as mayflys nymphs and shrimp

Question 12

you have a drawing of a river, there is an organic pollutant at point X. Point B is closest down stream to point X, explain what will happen here?

Answer 12

here the organic pollutant levels are highest and the invertebrates found willl be tolerant species such as rat-tailed maggors and blood-worms.

Question 13

you have a drawing of a river, there is an organic pollutant at point X. Point C is quite a bit further down stream to point X, explain what will happen here?

Answer 13

pollutant levels are decreasing as they become more dispersed.

here you would still find blood worms, but maybe some water louse too.

The BOD is lower than point B but still higher than A.

Question 14

you have a drawing of a river, there is an organic pollutant at point X. Point D is really far down stream to point X, explain what will happen here?

Answer 14

at this point the organic pollutant is mostly broken down. You would therefore see pollutant intolerant spcies again.

BOD is back to point A because the pollutnt is broken down.

Question 15

what are the six steps of eutrophication?

Answer 15

1- Addition of fertiliser (excess nutrients from fertilisers are flushed into the water by rainwater).

2- plant algae growth

3- sunlight blocked (due to alge blooms, other organisms die).

4- decomposition (depletes oxygen in water)

5- oxygen depletion

6- death of organisms (due to lack of oxygen)

Question 16

what is the definition of eutrophication?

Answer 16

eutrophication is the natural or artificial enrichment of a body of water, particularly with respect to nitrates and phosphates, that results in the reduced oxygen in water.

Question 17

what is euthropication often accelated by?

Answer 17

human acivities that add detergants, sewage or artifical ferilisers to water.

Question 18

what is a nutrient load up?

Answer 18

exessive nutrients from fertilisers are flushed from land into lacks or rivers by rain fall

Question 19

what are some changes that eutrophication may wraught?

Answer 19

turbidity increases and may reduce the amount of sunlight reaching submerged plants.

rate of deposition of sediment increases. increases the speed of water and lowers lifespan or lakes.

NPP is usually higher than unpolluted waters because of blooms.

diversity of primary producers changes and later decrease annually, The dominant species may change. Diversity of prodiucer may initially increase, as the eutrophication processes, alge blooms give way to cyanobacteria.

fish communites become dominated by surface-dwelling couase fish such as perch, other spcies migfrate from area if they can.

Question 20

what are the impacts of eutrophication on society?

Answer 20

Financial- loss of fertilisers from fields may reduce crop productivity and therefore farm yield and profit.
cost of treating nitrate enriched waters are expensive.

health- Nitrate enriched water is associated with higher risks of stomach cancer