Topic 4: Water and aquatic food production systems and societies

Question 1

Outline how energy drives the hydrological cycle.

Answer 1

solar energy
1. evapouration of water bodies
2. transpiration of trees

wind energy
movement of clouds to land from sea

Question 2

Explain how regional differences in the hydrological cycle influence the formation of different biomes.

Answer 2

1. Tropical rain forests experience high precipitation increasing productivity thus the water cycle influences increased plant growth.
2. Tundra have water in form of ice because it is frozen thus it is unavailable for plant reducing productivity.

Question 3

Explain, with the use of a system diagram, how human activities affect flows in the global water cycle.

[7]b.

Answer 3

ACID RAIN, DEFORESTATION, WATER POLLUTION, GLOBAL WARMING
GWEIC
1. Deforestation reducing transpiration
2. Global warming = increased temp = increased evapouration
3.Acid rain due to pollution affecting precipitaion

WATERPOLLUTION REDUCES CLEAN WATER AVAILABLE

Question 4

TRANSFERS VS TRANSFORMATIONS EXAMPLES in the water cycle

Answer 4

transfer:
precipitaiton
flooding
plant uptake;

transformation:
freezing
evaporation
/condensation
/sublimation/snowmelt/transpiration;

a.i.

Question 5

WHATS URBANISATION

Answer 5

urbanisatioon is the tranformation of a rural landscape to an urban area

Question 6

Outline four ways in which urbanization may influence processes in the hydrological cycle.

Answer 6

GWEIC & defforestation…

GLOBAL WARMING AFTER DEFFORESTATION

THEN ACID RAIN UNDER POLLUTION

GWEIC in full
GLOBAL WARMING
WATER POLLUTION
EUTROPHICATION
INTENSE IRRIGATION
CLIMATE CHANGE

Question 7

Explain how deforestation in the taiga may impact the world’s oceans.

Answer 7

1. incresed co2 because trees absord co2 in photosynthesis causing global warming which increases temperatures increasing rate of evapouration reducing water levels/ drying up water sources
2. increased temperature encourages ice melting increasing sea levels
3. no plant cover on land encourages soil erosion which can help nutrients like phosphates come from land to water causing eutrophication

Question 8

To what extent are water scarcity issues better addressed through changing human behaviour than through technological development?

Answer 8

Water scarcity definition

Solutions to water scarcity
1.increase water resourviours
2.collect rain water
3.gmo drought resistant crops
4.educate on better farming methods
5.ban phosphates
6.laws on water pollution

Relate any of these solutions to water scarcity to gweic or to either tech or changing human behaviour

REMEMBER THAT WATER POLLUTION LEADS TO WATER SCARCITY AS IT CONTAMINTES THE WATER AVALIABLE FOR INTAKE MAKING IT LESS WATER AVAILABLE.

Question 9

Outline two reasons why some countries are unlikely to experience water scarcity.

Answer 9

Geographical location with favourable climate where precipitation is high

countries may have large water sources (e.g. lakes/rivers/ice);

LEDCs VS MEDCs; developed countries with technology for effective water harvesting / desalination;
low population densities (with lower industrial/agricultural/domestic demands);

Question 10

Identify two possible human influences, not related to climate change, that may cause the changes in water scarcity predicted for 2025.

Answer 10

GWEIC
increased population (demanding more water);
increased/intensive food production/agriculture (demanding more water);
increased standards of living/industrialization (demanding more water);
increased levels of contamination/pollution (through industrial development);
damming of river/water supply upstream reducing available water downstream;
increased surface run off due to urbanisation;

GWEIC in full
GLOBAL WARMING
WATER POLLUTION
EUTROPHICATION
INTENSE IRRIGATION
CLIMATE CHANGE

Question 11

Explain how the growth in human population can affect local and regional water resources.

Answer 11

INCREASED DEMAND
THEN GWEIC
INCREASED POLLUTION
INCREASED INTENSE IRRIGATION
INCREASED GLOBAL WARMING THUS INCREASING WATER SCARCITY
growing human populations result in increased need for water for domestic/drinking/cooking use;
Commercial development/industrialisation/factories increase water demand;
increasing food demand entails increased irrigation/water for crops/agriculture;
increasing populations may increase poverty and thus economic water scarcity;
areas/locations/countries that have physical water scarcity would be mostly affected;
…causing freshwater land resources (lakes, rivers) to dwindle / risking sustainability of freshwater- resources / depletion of aquifers;
…often resulting in conflict over access to water;
increased groundwater abstraction may lead to intrusion from salt water;
(increased) industrial effluents can cause water (toxic) pollution;
dam construction to meet higher demands of growing population can affect sustainability of that water source;
increasing populations can stimulate technological innovation and greater efficiency of water use / management;

The points above may be credited through a case-study eg

Question 12

To what extent can different environmental value systems contribute to both causing and resolving the problem of water scarcity?

Answer 12

DEFINE ALL THE EVS
CAUSING
GWEIC
SOLVING
INCREASEING WATER RESERVOURS
HARVERTING RAINWATER
GMO DROUGHT RESISTANT CROPS
BAN PHOSPHATES
LAWS ON WATER POLLUTION
EDUCATE FARMERS ON BETTER FARMING METHODS
RRGP

GWEIC in full
GLOBAL WARMING
WATER POLLUTION
EUTROPHICATION
INTENSE IRRIGATION
CLIMATE CHANGE

understanding concepts & terminology of environmental value systems; technocentric; anthropocentric; ecocentric; pro-growth agenda; intensive agriculture; unsustainable extraction; industrialization; water contamination; climate change and rainfall patterns; desalination; rainwater harvesting; water taxes; grey-water cycling; etc
breadth in addressing and linking range of environmental value systems with impacts of unsustainable extraction; contamination; distribution of water supply and solutions through technology; changes in behaviour; social controls; etc
examples of value systems; impacts on water availability; specific strategies for
addressing water scarcity; appropriate technology; etc
balanced analysis of extent to which different value systems have promoted causes of water scarcity and/or effectively addressed resolving the issue; acknowledging relevant counter-arguments/alternative viewpoints;
a conclusion that is consistent with, and supported by analysis and examples given eg it is the technocentric pro-growth agenda that has largely contributed to the problem of water scarcity and while technocentric solutions are available to address it, it is only the ecocentric solutions that address the root cause and attempt to curb consumption. NB This is only an example of a possible conclusion. Candidates’ conclusions do not have to agree.

Question 13

Outline how climate change may affect the availability of freshwater resources.

Answer 13

GLOBALWARMING =EVAPOURATION AND MELTING OF ICE
CLIMATE CHANGE = LESS RAIN

increased temperatures/evaporation may lead to increased loss of soil water/aridity/desertification;
increased temperatures/evaporation may cause loss/salination of water supplies lakes etc;
changes in precipitation/increased frequency of El Nino events may lead to increase/decrease of water supply/droughts;
rising sea levels may lead to inundation/salination of ground water;
increased temperatures may cause melting of glaciers/ice caps leading to increase/decrease of water availability (i.e. by increased input to lakes/run-off to oceans).

Question 14

Outline one reason why aquaculture production has increased globally

Answer 14

Increased food demand from increasing population
SOURCE OF INCOME

Question 15

Identify four strategies that can be used in the sustainable management of wild fisheries.

Answer 15

• regulations against overfishing/
• regulations against fishing endangered species;
• restriction of fishing zones;
• restrictions/bans on types of fishing gear (including /dynamite fishing);
• research and support of calculation of maximum sustainable yield;

Question 16

To what extent is pollution impacting human food production systems?

Answer 16

EFFECTS OF WATER POLLUTION ARE BLEW

First think what are the two food production systems?
1. Aquatic
2. Terrestrial
Then think; how are they polluted
1. Water pollution
2. Soil pollution/degredation

Then the impact/effects of both these polltuions of food prodcution
Water pollution; BLEW
-bioacummulation
-eutrophication
-

understanding concepts and terminology of aquatic and terrestrial food production; aquaculture, capture fisheries, aquatic sp. harvesting; provision of food to a growing population; aquatic pollution sources; wide range of parameters lowering water quality; soil content; soil degradation; soil fertility; sustainability of TPSs influenced by industrialization, fossil fuel use, mechanization, fertilizers, pesticides; acid deposition; tropospheric ozone; ozone depletion; eutrophication; dead zones; climate change (Note: Relevant examples will be of pollution affecting food production NOT the other way round);
breadth in addressing and linking a range of pollutants/polluting activities (fertilizer use/emissions from combustion of fossil fuels/mining/waste disposal etc) and their impacts on food production systems (aquaculture/terrestrial farming systems) and methods of limiting these impacts (alternative sources /regulations/clean-up procedures);
examples of food production systems; farming practices (aquatic and terrestrial); impacts of pollutants/polluting activities; and methods of limiting impacts;
balanced analysis of the extent to which a range of pollution events are impacting, or being restored/prevented from impacting, a range of different food production systems;
a conclusion that is consistent with, and supported by, analysis and examples given eg ‘Terrestrial FPSs are affected by a wider range of pollutants and polluting activities, thus aquatic FPSs show a greater potential for sustainable production feeding the fast-growing global population’.
c.

Question 17

Discuss the role of humans in the destabilization of ecological systems.

Answer 17

Destabilization of ecosystems is the disruption to the natural balance of ecological systems.
thus postive feedback towards tipping point.

GWEIC, BLEW N BRE

GWEIC CAUSES BRE
D N BLEW

Effects include/ human impacts/ influences include;
overexploitation/ overfishing
/unsustainable harvesting,
pollution,
habitat degradation/destruction,
unsustainable development, etc
Loss of resilience
Loss in biodiversity
Loss in ecosystem services
BRE

GWEIC eg overfishing, intensive agriculture, C emissions/global warming, water/atmospheric pollution,

CAUSES BRE

GWEIC in full
GLOBAL WARMING
WATER POLLUTION
EUTROPHICATION
INTENSE IRRIGATION
CLIMATE CHANGE

BLEW in full
Bioaccumulation and biomagnification
Loss in aquativ life
eutrofication
Water borne diseases

BRE in full
Loss of resilience
Loss in biodiversity
Loss in ecosystem services

overfishing reduces the storage size of targeted fish populations reducing their stability, C emissions lead to climate change that reduces primary productivity of systems, eutrophication will interfere with negative feedback loops in freshwater systems, atmospheric pollutants may eliminate sensitive species of lichen reducing diversity, etc and positive impacts on stability e.g. in-situ conservation protects complexity of relationships in system, agricultural techniques conserving soils maintain high productivity, etc
balanced analysis of the extent to which human activities promote or prevent destabilisation of ecological systems with acknowledgement of relevant counter-arguments/alternative viewpoints.
a conclusion that is consistent with, and supported by, analysis and examples given eg “The role of humans in destabilising ecological systems is very diverse, and with the current size and growth of population, the magnitude of that role is becoming immense, calling for urgent and wide-scale efforts to adopt a proactive role in re-stabilising those systems.”

Question 18

Define biochemical oxygen demand (BOD).

Answer 18

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.

Question 19

Outline how turbidity changes after the raw sewage discharge point

Answer 19

turbidity will increase due to bacteria grow as they consume/decompose the sewage;

turbidity will increase at the point sewage enters the water, as the pollutant is particulate/coloured;

turbidity will increase after the outlet of sewage as bacteria grow rapidly as they consume/decompose the sewage;

turbidity remains high as algae now rapidly grow as there are nutrients from the sewage decomposition available;

turbidity decreases once the nutrients levels fall to the pre-sewage levels and the algae growth declines;

turbidity increases as algae decrease, and then decrease as algae increase.

Question 20

Explain two factors which lead to a loss of marine (ocean) biodiversity.

Answer 20

Global warming high temperatures fish are sentive to
water pollution (BLEW)
eutrophication

Factor (F): global warming;
Explanation (E): leads to higher ocean temperatures to which many marine species are sensitive;
Explanation (E): some species cannot adapt/evolve/migrate quickly enough / compete successfully, leading to loss in biodiversity/extinction;
Explanation (E): changing temperatures may reduce productivity by phytoplankton leading to loss of diversity throughout the food chains;
Explanation (E): higher temperatures may lead to coral death/bleaching affecting whole food webs/ecosystem;

Factor (F): ocean acidification;
Explanation (E): leads to coral bleaching (especially at higher ocean temperatures);
Explanation (E): most marine organisms have a very narrow band of tolerance for pH (shells won’t develop) leading to possible extinction and loss of biodiversity;

Factor (F): pollution from plastic;
Explanation (E): tiny pieces of plastic ingested by organisms may carry associated persistent organic pollutants(POPs)/toxins that can be absorbed and passed along food chains;
Explanation (E): marine organisms become entangled in plastic and unable to feed/suffocate;
Explanation (E): marine organism/scavenging birds ingest plastic causing suffocation/starvation;

Factor (F): pollution from oil spills;
Explanation (E): oil spills will take long time to degrade, having a long term negative impact on ecosystems and biodiversity;
Explanation (E): oil leading to animals losing their protection to cope with cold/waterlogging/drowning;

Factor (F): overfishing/unsustainable fishing methods/hunting of keystone species;
Explanation (E): some fishing methods (e.g. bottom trawling, electrocution/poison/explosives) are indiscriminate and take all organisms leading to the loss of all organisms from an area;
Explanation (E): some fishing methods destroy the habitats (e.g. scallop dredgers or bottom trawlers) leading to local loss of diversity;
Explanation (E): if fish populations are harvested at rates greater than replacement then loss of numbers will lead to possible (functional) extinction;
Explanation (E): nets and fishing lines can entangle seabirds (especially Cormorants) and marine mammals (e.g. fur seals in Sub-Antarctic);
Explanation (E): Hunting top carnivores e.g. shark can disturb food webs leading to loss of diversity.

GWEIC in full
GLOBAL WARMING
WATER POLLUTION
EUTROPHICATION
INTENSE IRRIGATION
CLIMATE CHANGE

BLEW in full
Bioaccumulation and biomagnification
Loss in aquativ life
eutrofication
Water borne diseases

BRE in full
Loss of resilience
Loss in biodiversity
Loss in ecosystem services

Question 21

Outline an environmental problem that may result from the release of untreated sewage into a river.

Answer 21

BLEW

eutrophication / algal bloom;
… due to high levels of nitrates and phosphates/nutrients;
hypoxic conditions;
… due to high oxygen demand;
rotten egg smell / production of hydrogen sulphide;
… due to anaerobic decomposition;
increase in micro-organisms/pathogens within shellfish;
… due to pathogens being filtered out of the water;
ill health in people / increase in waterborne disease;
…eating shellfish/fish contaminated with pathogens/bacteria (from sewage);
…from swimming in water contaminated with pathogens/bacteria (from sewage);
…drinking water contaminated with pathogens/bacteria;
death/loss of benthic species
… due to particulates blocking feeding/respiratory systems;
decrease in photosynthesis;
… due to increase in turbidity (reducing light penetration).

GWEIC in full
GLOBAL WARMING
WATER POLLUTION
EUTROPHICATION
INTENSE IRRIGATION
CLIMATE CHANGE

BLEW in full
Bioaccumulation and biomagnification
Loss in aquativ life
eutrofication
Water borne diseases

BRE in full
Loss of resilience
Loss in biodiversity
Loss in ecosystem services

Question 22

Explain how environmental indicators are used to assess sustainability.

[7]b.

Answer 22

environmental indicators (EIs) may involve measures of biodiversity/
pollution/population/climate/emissions/resource consumption;
EIs are tools for measuring progress toward sustainability/supporting policy evaluation/informing the public/comparing nations;
EIs involve the setting of measurable goals from established baseline measurements;
EIs can be used at a range of scales from local to global;
after some time, measures can be reassessed and compared to the baselines/domestic objectives/international agreements (eg Kyoto/Montreal Protocol);
environmental impact assessments (EIAs) are EIs that measure a wide profile of indicators usually before and after some development;
ecological footprints(EFs) are EIs that focus on rates of consumption compared to rates of natural income;
if a population’s EF is greater than the area available this indicates unsustainability;
the Millennium Ecosystem Assessment used indicators to give a scientific appraisal of the condition/trends in the world’s ecosystems and services;
certain species can be used as indicators of pollution;
some indicator species are particularly sensitive to pollution so a low abundance may suggest heavy pollution / high abundance suggest clean environment (eg lichens);
loss of these sensitive species may be an effective indicator for appealing to the public;
some indicator species are particularly resistant to pollution so a high abundance/dominance of these species may suggest high pollution (eg tubifex worms/coliform bacteria).

Question 23

Describe the similarities and differences in using a biotic index and a diversity index to assess ecosystems.

Answer 23

Similarities:
both indices involve evaluating the range/variety of different species;

Differences:
diversity indices are appropriate for most ecosystems whereas biotic indices are usually for aquatic systems;

both may involve species identification;
both may involve quantitative sampling/estimating the abundance of living organisms;
both require multiple samples for effective comparisons/reliability;

both involve calculating a single figure (index) from a collection of data;

Differences:
only biotic indices (not diversity indices) give different values to sensitive and tolerant species;
biotic indices are specifically used for evaluating impact of pollution whereas diversity indices just measure variety and evenness of species/general condition/maturity of an ecosystem;
diversity indices are appropriate for most ecosystems whereas biotic indices are usually for aquatic systems;
biotic indices usually focus on animal species/macroinvertebrates alone whereas diversity indices can be used for plant or animal communities;
diversity indices usually address all species present in system whereas biotic index focuses on a particular selection;

Question 24

Explain how the production of cash crops (such as pineapples) may have an environmental impact on lakes or rivers.

[1]a.ii.

Answer 24

eutrophication is the answer
pesticides
blew

GWEIC/BLEW/BRE

use of fertilizers/leaching of nutrients can lead to eutrophication/algal blooms;
use of pesticides can lead to contamination of aquatic systems/death of non-target organisms/bioaccumulation;
over-abstraction of water for agriculture use may lead to low water levels (in rivers/lakes adversely affecting fish/aquatic species);
soil erosion into lakes/rivers could increase sedimentation/reduce water clarity;

Note: For credit the cause and effect needs to be linked.

a.ii.

GWEIC in full
GLOBAL WARMING
WATER POLLUTION
EUTROPHICATION
INTENSE IRRIGATION
CLIMATE CHANGE

BLEW in full
Bioaccumulation and biomagnification
Loss in aquativ life
eutrofication
Water borne diseases

BRE in full
Loss of resilience
Loss in biodiversity
Loss in ecosystem services

Question 25

Wild fisheries vs aquacultures

Answer 25

Wild Fisheries: Wild fisheries involve harvesting fish and other aquatic organisms from natural water bodies such as oceans, rivers, lakes, and streams. Fishermen catch fish using various methods such as netting, trawling, longlining, and trapping.

Aquaculture: Aquaculture is the farming of aquatic animals with human intervention in the rearing process. Aquaculture operations may raise species native to the area or introduce non-native species for cultivation.

Question 26

Destabilization of ecosystems (BRE)

Answer 26

Destabilization of ecosystems is the disruption to the natural balance of ecological systems.
thus postive feedback towards tipping point. (BRE)

Question 27

ENVIRONMENTAL INDICATORS DEFINITIION AND EXAMPLES

Answer 27

These measure the pollution/ diversity of a population
EF
BOD
Indicator species
Biotic index