Hydropower Flashcards
Columbia River, USA
Salmon
in need of management and conservation
historic pacific salmon population
Prior to 1800 between 10-16 million returned to Columbia each year.
What is it important
economic- $142 million per annum to local economy (2005)
Cultural- tribed (subsistence food source and trading)
Ecological- life history stratergy. Life cycle anadromous (span fresh shallow down river. smogs, estuary and oceas= feeding (organic matter) then migrate upstream. many bears osprey invertebrates quality originalisms thrive of ocean organic matter)- strong nutrient/biomass link between ocean and river ecosystems
stealhead- migratory rainbow trout
Hydropower
antroprogenic- construction of huge wide scale dam construction 1930- 1970s hydroelectricity. impact on physical characteristics. pervasively free flowing not slow flowing reservoirs.
benefits of hydropwer
hydropower provide 87% of washintons exports
-interrgional and international
irrigation
flow regulation
flood control
transportation
drawbacks of hydropower
alter flow regimes
loss of water through irrigation flooding salmon habitat impediemnt to fish increased predation and stress delayed migration damage to fish that pass through turbines- blade strikes, pressure fluctuations, shear forces, turbulent waters disorientating fish
Mitigation - England, Eastern Seaboard (USA), Western Seaboard (USA)
England- (should keep waters free from impacts from construction)
-Kings gap- 12C “english rivers should be kph free from obstruction so that a well fed pig can stand sideways w/o touching either side)
Manga Carter 1215- “provision for removing weird and to protect salmon for use of public good throughout all of England”
Salmon and freshwater fisheries act 1975
Eastern Seaboard-
17th- 19th century mills wee main source of mechanical power
milldams require to divert though mill system
addition to blocking water- also block fish
complaints from citizens accustomed to obtaining fish
18th C dams had to have openings to less fish pass ruing their migration
Western Seaboard-
fish and wildlife coordination act (1943)
federal power act (1935_
mitchell act (1938)
endangered spiced act- 1973 bit too late lots of dams already been constructed
pacific northwest electric power planning and conservation act 1980
Assess impacts of dams on salmon population
- baseline data from predam era
search for historic data
use appropriate control site
construct empirical studies
modelling
Tinned salmon commericial slamon harvet correlates with construction of dam
also depicts the decline of the industry- after WW shift to fresh produce
Adult chinook salmon return to Bonneville Dam since it was build 1983- shows no strong correlation, maybe cyclical pattern, 2.3 million adults returned last few years
more effort, more money, more advanced mitigation tech improve at improving numbers
decline un upper reaches shows number of adults spawning is decreasing
strong pro-dam/ anti dam lobbying groups
Best guess:
historic salmon returns = 10-16 million adult per annum
chinook salmon rund on teh comluia ere the largest in the world?
what we know: runs have declines by 90% (1.5 million returns 1990s)
upturn in returns during late 1990s early 2000s - ocean conditions, improvements in management mitigation)
4 H’s
Population status: Habitat Hydropower Harvet Hatchery- one of biggest mitigation techniques used on the river (ecological conditions) (unknown effects) (trend) (abundance)
Mitigation
Fish ladders
Mitigation Hatcheris
Transporation
Fish Ladders
Hotspot for predation and disease
Hatchery
millions of pacific salmon mostly are realised from hatcheries annulation
people in area not happy with this technique
Transportation
Barges and then released- not exposed to delay in fore bays or mortality during turbine passage
problem is speed (couple of says but naturally would take weeks) physiologically ready for saline conditions? making way back?
Conclusion
EIA made difficult w/o good baselines data
absence of baseline data: use historic information use a control site model historic conditions conduct empirical studies
catch data alone can be misleading (need catch per unit effort)
confounding factors can seriously distort interpretation
ocean conditions, more dams constructed, improvements in mitigation/ management
Measuring impacts and UK perspective
collecting empirical data: tagging/ telemetry
passive intergrated transponder (PIT) tags
surgically implanted- moves through detected at pit antenna and readers this info will be recorded.
PITS/ Tags
Advantages of TAGS/PITS
only cost £1.5 - £2.5 each
no internal power to tag life
tags small so easy to implant and less likely to impact swimming performance
fixed readers can automatically record fish passage
Disadvantages PIT TAGS
fish are only detected if in close proximity to the readers
relatively ineffective in saline waters due to water conductivity (but not completely impossible to use them)
Radio Tags
wilflife radio tags typically use brief pulses of the carrier frequency
-extends tag life
-easier for humans to detect discrete pulsed signals against the continuous noise from FM broadcasts
often used to gain animal positions, motor movements, recapture the animal
can store behavioural/ environmental information (modern - pressure up down water column searching for passage) body temp bahviroual thermal regulation more optimal temperature (climate change)
Radio Telementry Advantages
mobile tracking by foot, boat, plane- fish can be detected w/o needing to be near fixed antennas
fixed antenna can have a large range (up to 1 mile)
finner resolution information compared to PIT tags
- allows migratory routes to be calculated
Radio Telemetry Disadvantges
more expensive than PIT tags, sample size reduced if working on budget
battery supply means tags are larger an have limited life expectancy
surgery moer invasive
farily ineffective in saline conditions (radio waved travel poorly)
Acoustic Tag
transmit an underwater sound pulse or ping that is detected by a hydrophone (up to 25 seconds or 1 every 16 seconds)
tags programmed allowing identification of idiviual fish
tags can be small (
Advantages of Acoustic tags
fixed arrays of hydrophones allows 3D positioning of fish
fine scale behaviour can be ascertained (
disadvantages of Acoustic tags
more expensive than radio tags (sample size further reduced)
limted tag life- trade off between ping rate (resolution) and tag life
-size of tag and tag life
mobile tracking harder as hydrophones need to be submerged
less effective in “noisy”
impact of dam on downstream migrating smelt life-stages
Williams et al 2001- survival of chinook salmon and steelhead through snake and columbia river dams
- as more dams - survival decreased
since 70s serval improved significantly
-improvements in downstream bypass facilities
-changes in dam operation
smolt to adult return remained low
unlikley to be related to direct mortality of smolts within the HEP system
impact of a dam on downstream migrating smolt life-stages
Muir et al 2001- survival through different routs on 2 snake river dams
results: spil bays w/o flow deflectots= 98.4-100%
spill bays with flow deflectors- 92.7- 100%
By pass system 95.3-99.4%
Turbines 86.5-93.4%
management implications
- how best to operate dams
- efforts to improve efficiency and survival should continue
How does the release of hatchery fish impact wild fish?
massive> in hatchery released over 100 years
now over 130 m juvenile chinook released per yr
approx 75-80% of adult returns from hatchery origin
Levin et al 2001
Juvenile and adult passage countts recorded at lower granite dam
data used to estimate survival from juvenile outmigration to adult spawning migration
SARs typically 0-5%
fluctuations in ocean conditions impact food availability
high numbers of haterchy released fish > competition for food
density dependent mortality of wild fish , highly depleted stock
Hatcheries could hinder recovery of wild stocks
Hydropower development in the UK
LPA permssion
(acceptable use of land)
EA permits
(design/ operation to ensure envt protection)
does the developer need to submit an ES?
Schedule 2
decision on EIA requirements based on:
threshold if development of >5MW= much more likely to require EIA
developer under 0.5 MW may still require EIA
development are judged by virtue of the nature, size and or location
Issues identifies during scoping often relate to:
research and development related to these issues aim to reduce impacts of hydropower development
Injury/ mortality to downstream moving fish
- mitigation: investigate, develop and use ‘fish friend designs” i.e. hydrostatic pressure converters, archived screw turbines
Habitat fragmentation for fish
- incorporate a fish pass into the proposal
- poor efficiency for certain species
pool and wire pass- passage eff= 5%
denil pass: passage =0%
- solution: develop and use more effect solutions
Threshold
Threshold for consideration is at 0.5 MW, developments > 5 MW = EIA likely,
