Antropogenic disturbances Flashcards
Organic pollution
input of organic matter into waters and the resulting reduction/depletion of DO and high ammonia concentrations –> disappearance of fish and invertebrates
saprobity
state of an aquatic ecosystem resulting from the input, decomposition and removal of organic matter
can be asserted by metabolic-dynamic measurements and analysis of living communities
frameworks
water frmework directive
urban water treatment directive
integrated pollution prevention
control directive
nitras directive
Eutrophication
scetch
Impacts: deadzones, harmful algae bloom, biodiversity loss, increase airborne toxic contaminants
Thermal pollution
most common cause: using water for cooling for power plants
stress or death , decreases oxygen availability, alters nutrient cycles, makes waterbody vulnerable to chemicals
Acidification
acid rain (directly or though catchments
can be naturally buffered by type of soil
low H –> toxic effect n some organisms and can slo cause the release of toxic metal from sediments
limestone can be added
recovery can take decades
Salinization - types
Primary (natural): Rainfall, rock weathering, seawater intrusion and aerosol deposits
Secondary salinization (exacerbation of natural processes
- highly saline irrigation flows from agriculture
- more rapid chemical weathering because of construction
- application of salt to roads
Salinization
electrical conductivity –> increased energetic demand to maintain homeostasis
ions can be toxic
effects on humans
Salinization - combatting
Changing agricultural practices that use less water (less salt polluted water as runoff)
reducing use of salt as deicers
treat point sources before they are discharged into frehwater
Invasive spezcies
is an alien sppecies (specimen introduced outside of it’s natural range that might reproduce) whose introduction has been found to threaten or adverely impact upon biodiversity
One of the biggest threats to biodiversity and the secon leading cause to animal extinction
pathways: aquaframing, fisheries, pet trade (America and east asia)
Invasive species - combatting
Prevention: bans on breeding, placement on the market, use of certain species as well as the treatment of ballast water from ships before being discharged
Early detection and rapid eradication: survey and detect IAS and eradicate them as soon as possible
Management: prevention from spreading further –> population conrol
Hydrological regime
Rivers: quantity and dynamics of flow, connection to ground water
Lakes: same as rivers + residence time
Morphological conditions
Rivers: depth/width variations, structure/substrate of riverbed, strucute riparian zone
Lakes, depth variation, quantity/structue/substrate of lakebed, structure of shore
River continuity
Possibility of sediment and migratory species to pass along the river
River typology, reference conditions
based pon bioregion, altitude and catchment size
Morphological alternations
Bank dynamic: stabilization of riverbanks, change in river profile and connectivity to floodplains -> loss of diversity and space for retreat at disasters
Bed dynamic: stabilization of riverbeds, change in connection to roundwater -> reduced oxygen supply, clogging
Instream structures: natural structures in
stream, removal -> loss of spooning sites and diversity
Bank vegetation: regulation of microclimate, source of nutrition -> changes of light regime and nutrient supply
Course changes
Hydrological alternations
Water abstraction, minimum flow: reduction in flow -> barriers for fish, loss of space for retreat
Hydro peaking: change in flow -> species drift, changes in sediment regime
Impoundments: change in flow velocity, sediment transport and erosion -> reduced oxygen, change
in sediment composition, clogging
River continuity interruption
River and habitat continuity interruption, change in sediment transport –> barriers for fish, loss of space for retreat
Response measure
Responses can vary largely, a few exampls would be fish passes, river restorations or minimum flow surveys
