pollution 1

Question 1

traditional pollution

Answer 1

acidification and organic pollution

Question 2

emerging polutants

Answer 2

plastic, nanomaterials, pharmacuticals

Question 3

effect of acidification and organic pollution on river population

Answer 3

stressor -> impacts biodiversity -> impacts ecosystem

Question 4

organic pollution

Answer 4

large quantities of organic material that acts as a substrate for microorganisms is released into water courses

Question 5

organic pollution: ecosystem impact

Answer 5

substrates and microorganism use causes oxygen depletion
organic effluents can be liquid or contain suspended solids: reduce light penetration which impact river producers e.g. algae
changes river characteristics e.g increasing silt-like characteristics

Question 6

sources of organic pollution

Answer 6

urban run-off
industrial effluents
sewage
farm waste

Question 7

sources of organic pollution: sewage effluence

Answer 7

largest source of organic pollution in UK
not all household sewage is treated, especially in excess rain
80% sewage is treated before being released, this reduces pollution load by 90%

Question 8

sources of organic pollution continued

Answer 8

urban run-off can enter rivers directly with severe impacts especially during storms
farm effluence is an increasing problem as agriculture intensifies
complex array: multiple sources; multiple stressors
obligation of government and land owners to prevent organic pollution

Question 9

oxygen sag

Answer 9

oxygen levels decrease down stream due to organic pollution sources as decomposers metabolise waste materials

Question 10

effect of organic pollution on rivers: clean zone and decomposition zone

Answer 10

upstream clean zone: oxygen rich, with diverse invertebrates and fish
decomposition zone: (pollution point) low oxygen, some species die, some worms with high haemoglobin thrive and species that eat them (e.g. mosquito and midge) thrive - low diversity but high abundance - stress tolerant community

Question 11

effect of organic pollution on rivers: recovery zone and clean zone

Answer 11

recovery zone: oxygen levels recover, mixing of water sources, quick to recover
clean zone: down stream
variation in size of these zones

Question 12

impact of organic pollution on algae and fungi

Answer 12

ammonia inc downstream
downstream release of nitrates and phosphates due to microbes
sewage fungus grows around sewage output, forms biofilm
spike in algea downstream due to increased nutrients
surge in productivity downstream due to increased nutrients- unstable

Question 13

impact of organic pollution on other species

Answer 13

Tubificidae (blood worms) benefit from silty river conditions
asellus (crustacean) tolerate pollution

Question 14

protozoa and pollution sites

Answer 14

protozoa dominate pollution sites
prefer silty environments over erosional ones
mayflies are especially sensitive
some fish are mobile and can avoid incidents but severe pollution kills fish
recovery begins with stickleback, salmonoids sensitive and OP can impact migration

Question 15

ecosystem services that may be impacted in rivers (part 1)

Answer 15

biomass production: primary productivity (plant growth) secondary production (animal growth) organic matter transformation and decomp (e.g. leaf litter break down)
ecosystem metabolism - respiration and photosynthesis ratio
external cycling of nutrients

Question 16

ecosystem services that may be impacted in rivers (part 2)

Answer 16

physical structuring: sedimentation, microbial biofilm development, island formation, partial flow
ecosystem properties: stability of ecosystem processes (resilience), temporal variation
ecosystem values (for humans) water quality, food provision, nutrient cycling, carbon sink

Question 17

ecosystem consequences of local extinction: three hypothesis

Answer 17

species primarily redundant: if a species is removed the ecosystem continues to perform (substitutable contribution)
species are primarily singular: if the species is removed the ecosystem is impacted (unique contribution)
species are idiosyncratic or unpredictable because their impacts are context dependent
2 things: biodiversity and ecosystem function

Question 18

ecosystem function null hypothesis

Answer 18

biodiversity loss does not effect ecosystem processes

Question 19

ecosystem function: diveristy-stability hypothesis

Answer 19

biodiversity loss has a linear correlation to ecosystem process (each species acts independently and is equally important)

Question 20

ecosystem function: redundancy hypothesis

Answer 20

species loss within groups with the same ecosystem function has little impact on the ecosystem

Question 21

ecosystem function: the rivet hypothesis

Answer 21

the redundancy hypothesis stacked repeatedly
species loss within groups with the same ecosystem function has little impact on the ecosystem
large impacts occur when all species of one function exterminated and this repeats
species are replaceable to some degree until entire ecological niche is no longer fulfilled and ecosystem becomes unstable
There is a level of species loss that an ecosystem can tolerate

Question 22

ecosystem function: keystone species hypothesis

Answer 22

high level of species singularity – some species have disproportionately large influence on processes (one species loss could potentially cause ecosystem collapse) e.g Cassowary bird in NZ needed to plant tree (Ryparosa) seeds by digesting and egesting seed

Question 23

lecture conclusions

Answer 23

• Ecosystems are subject to multiple stressors, including acidification and organic pollution
  -These stressors lead to profound biodiversity loss, creating damaged ecosystems
• Biodiversity loss may reduce ecosystem functioning, and lessen ‘insurance’ against environmental change