Block D - Exam Page (Human Impacts on river ecosystems)

Core Mechanism Cluster: catchment disturbance - runoff increases / sediment increases / pollutants increase = habitat quality declines

• Walsh (2005) – urban stream syndome = tolerant taxa dominate 

• Omerod & Durance (2009) - UK uplands = partial reocvery after liming 

Core Mechanism cluster: Flow alteration

• velocity change / stagnation = oxygen declines + habitat loss

• Subbington et al. (2009) - drought = proving hyporheic refuge 

• Sor et al. (2023) - Mekong river = dams reduce fish diversi

Core Mechanism cluster: chemical stress

• pH / metals levels increase in water = physiological stress / mortality

• Marques et al. (2021) - Amazon = deforestation lowes invertebrate richness 

• Richo-Sanchez et al. (2022) - mining = shows metals decrease Macroinvertebrates 

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