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Fish protection at hydroelectric water intakes : State of the Art

Damien Sonny PhD Fish Biologist ProFish Technology With the kindly share of information from Franรงois Travade, EDF R&D (France)

The paradoxical balance of hydroelectricity Fish mortality

Green energy

- Loss of biodiversity

+ Environment

Fish downstream migration

Migratory species : need to migrate from rivers to oceans European eel Atlantic salmon Shad European sturgeon

Holobiotic species : exhibit also downstream migration patterns In Belgium, 33 species of fish have been observed migrating downstream in the River Meuse, as revealed by fish impingement on the filters of a nuclear power plant cooling water intake

At least once in their life, fish migrate downstream

Index of juvenile stocks (% of 1960s-1970s)

A case of study : the eel stock today

150 Japanese eel American eel

European eel

100

50

0 1950

1960

1970

1980 Year

1990

2000

!! Hydroelectricity is not the only factor that contributed to the eel decline !! (overfishing, pollution, marine current problems, loss growth habitats,...)

Incontestable truth :

- Only adult eels are killed by passage through turbines - Reducing this impact means saving adults and ensuring eel reproduction and preservation in a very short future

-Beside the reduction of other main factors, this measure has priority to then reduce other impacts, and is now a legal constraint for the feasibility of new hydro projects

Does fish protection justify the limitation of hydropower production?

Recent technological advances in fish protection have been made by fish scientists 1. Development of fish upstream bypass : the French experience Lift bypass

Pool bypass

Denil bypass

Recent technological advances in fish protection have been made by fish scientists 2. Development of fish downstream bypass : Atlantic salmon smolts Surface salmon bypass, operating principle and parameters : Travade (EDF R&D)

- Bar spacing < 3 cm - Water velocity < 0,4-0,5 m/s - Location close to the screen - 2% to 10 % of the turbine discharge - No turbulence - No upwelling

Recent technological advances in fish protection have been made by fish scientists

On several dozen studies in France : Efficiency 80-90% with 2.5 cm bar spacing and good hydraulic conditions 60-80% with 3-4 cm spacing and good hydraulic conditions 10-20% with spacing > 5-6 cm

HALSOU (Nive)

BP

CAMON (Garonne)

BP

LAILHACAR (Gave dâ&#x20AC;&#x2122;Ossau)

Recent technological advances in fish protection have been made by fish scientists It is now possible to design efficient salmon surface bypass by taking into account the intake hydro-morphology, adequate discharge in the bypass and adequate position of the bypass.

Consult referenced scientists to design specific efficient bypass!

Recent technological advances in fish protection have been made by fish scientists 3. Development of fish downstream bypass : European silver eel study (Travade, EDF R&D) Halsou, 30 m3/s, 30 mm screen mesh

Surface bypass : 0,6 m3/s 10 % efficiency

3.5 m

Bottom bypass : 0,6 m3/s 48% efficiency

Recent technological advances in fish protection have been made by fish scientists All behavioural studies show that eel exhibit very variable behaviours in the forebay of a hydro water intake

BoubĂŠe, J. 2007

Recent technological advances in fish protection have been made by fish scientists Feedback of French experience (Travade 2007) Great importance of three main factors to protect silver eels : Vmax = 0.5 m/s in front of the screen Max bar spacing = 20 mm Natural escape on spillway according to the ratio turbine discharge/river discharge

Recent technological advances in fish protection have been made by fish scientists 4. â&#x20AC;&#x153;Fish friendlyâ&#x20AC;? intake principle

Recent technological advances in fish protection have been made by fish scientists

4. â&#x20AC;&#x153;Fish friendlyâ&#x20AC;? intake principle Fish protection with such physical constraints is only compatible for small and new hydro projects For larger hydro production, other measures have to be taken

Recent technological advances in fish protection have been made by fish scientists

5. A new behavioural barrier : the infrasound fish fence

Infrasound : - Low frequency (< 20 Hz) - Water particle displacement - Naturally produced by fish - Natural alarm signal for fish - Immediate and systematic fish avoidance response (>10 scientific publicatio

Recent technological advances in fish protection have been made by fish scientists

Our infrasound speaker 1-16 Hz 1.5 kW 130 kg 0.85 m x 0.75 m 180째 out of phase Synchronization

Recent technological advances in fish protection have been made by fish scientists Experimental design in Lake Borrevann (NO)

Echosounder

Infrasound source hanging beneath a raft

Recent technological advances in fish protection have been made by fish scientists Fish observations in Lake Borrevann Distance to the echosounder

Infrasound duration

30s

30s

30s Time

Recent technological advances in fish protection have been made by fish scientists Fish observations in Lake Borrevann Full night without infrasound : control 1h

Recent technological advances in fish protection have been made by fish scientists Fish observations in Lake Borrevann Full night with infrasound : treatment 1h

Recent technological advances in fish protection have been made by fish scientists Video observation of fish avoidance response in a quarry

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Recent technological advances in fish protection have been made by fish scientists Experimental installation on a cooling water intake (BE)

Electrabel Tihange The Nuclear Power Plant of Tihange (3000 MW) located on the International River Meuse Cooling Q ď&#x201A;ť 55 m3/s

Recent technological advances in fish protection have been made by fish scientists Experimental design at Tihange

Recent technological advances in fish protection have been made by fish scientists

Recent technological advances in fish protection have been made by fish scientists

Distance to the echosounder

Results at Tihange Infrasound OFF (22/01/04), 15h40-16h 146:1540-1600 OFF

Time

Recent technological advances in fish protection have been made by fish scientists Results at Tihange Infrasound ON (22/01/04), 15h20-15h40 Distance to the echosounder

146:1520-1540 ON

Time

Recent technological advances in fish protection have been made by fish scientists Effect of infrasound on fish passage

Upstream corridors: 81% and 86% reduction All corridors (54 m wide): 50% reduction

* = P < 0.05 ** = P < 0.001 *** = P < 0.0001

Recent technological advances in fish protection have been made by fish scientists

A full scale installation (6 infrasound loudspeaker) will be finished next week at Tihange (welcome for a visit!)

Infrasound is now considered as efficient on slow running lateral water intake Two hydroelectric power plant along the Gave de Pau River (France) will be installed during autumn to test the efficiency on eels

Conclusions Fish mortality at hydro water intake : - Better understood issue - Recent data and advances on target species - With the relevant knowledge, technological solutions can be designed - Technological solutions must be adapted to each site - Scientific consulting is necessary to design the best solutions available to your â&#x20AC;&#x153;fish problemsâ&#x20AC;?

www.profish-technology.be

Many thanks for your attention!!