/efficieny_of_fish_laders

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Efficiency of nature like fishpasses and their role for the integrity of running waters A. Zitek & S. Schmutz Institute of Hydrobiology and Aquatic Ecosystem Management Department of Water, Atmosphere and Environment BOKU - University of Natural Resources and Applied Life Sciences, Vienna, AUSTRIA

BOKU - University of Natural Resources and Applied Life Sciences Department of Water, Atmosphere and Environment

CONTENT

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INTRODUCTION Ecological background Consequences of continuum interruptions FISH PASSAGE SOLUTIONS Mistakes of the past Technical solutions Nature-like solutions Head waters Lowland rivers Example: „Marchfeldkanal“

EU-LIFE PROJECT „LIVING SPACE OF DANUBE SALMON„ Efficiency of measures (fish ladders/river restoration) within a Danube/tributary system SUMMARY

ECOLOGICAL BACKGROUND

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W inter Habitat

Spawning H abitat

Additionally:

dispersion

Refuge migration during high flood, compensation after flood, leave bad conditions, daily migrations, other migrations within the year..

Feeding H abitat

GENERAL CLASSIFICATION OF FISH MIGRATION

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Potamodromy - Migrations within freshwater

Diadromy • Anadromy: spawning migrations from salt to fresh water Atlantic and Pacific salmon, sturgeon • Catadromy: spawning migrations from fresh to salt water Eel • Amphidromy: shifts between salt and fresh water in both directions Northcote 1998

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MIGRATION DISTANCE Long distance migrants

> 300 km

Danube: Huso huso, Acipenser gueldenstaedti, Acipenser stellatus, Alosa sp.

Medium distance migrants

30 - 300 km

Danube: Hucho hucho, Chondrostoma nasus, Barbus barbus

Short distance migrants

< 30 km

Danube: all other species Waidbacher & Haidvogl 1998

CONSEQUENCES OF CONTINUUM - INTERRUPTIONS Longitudinal Weirs Turbines Artificial falls Impoundments Improper habitat

Residual flow Pollution Channelisation

Lateral Cutoff of flood plains tributaries

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Decrease of Ó species and genetic diversity Ó population size Spawning migration Drift of larvae Migration of juveniles Foraging migration Dispersion migration Refuge migration Recolonisation migration

ENDANGERMENT OF EUROPEAN FISH FAUNA

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all impacts

200 species

100 90 80 70

not affected 67 %

dams & weirs

%

60 50 40

affected 33 %

30 20 10 0

endangered

Northcote 1998

endangered-vulnerable vulnerable

CONSEQUENCES OF CONTINUUM INTERRUPTIONS IN AUSTRIA

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Example - Inn River: Hydroelectric power plant „Jettenbach“ build in 1920 25 20 15 Number of species

10 5 0

Originally

Today

FISH PASSAGE SOLUTIONS Õ ideal

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total passage original habitat

bypass channels Õnature-like

high qualitative & quantitative passage partial habitat substitution

Õsemi-natural

partial passage artificial habitat

Õ technical construction

passage

MISTAKES OF THE PAST

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TECHNICAL SOLUTIONS: VERTICAL SLOT FISH PASS

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NATURE LIKE FISH PASSAGE SOLUTIONS

General requirements Head waters Lowland rivers Summary

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bypass channel

river

GENERAL REQUIREMENTS • river type (upland /lowland ) • discharge conditions • gradient width depth substrate conditions

• • • •

species composition population size swimming capabilities life-history migration life stages spawning grounds

• gradient conditions • velocity conditions • required width and depth range • required flow • required length

ROCK RAMPS – HEAD WATERS (HIGH SLOPE) before

after

Only two species (Brown trout and bullhead)

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EXAMPLE LOWLAND RIVER (LOW SLOPE)

Marchfeldkanal weir 3

weir 4

Ru

Vienna

ßb

ach

artificial side-arm of Danube River, 19 km Reconstructed “Rußbach”, 36 km Regulated flow conditions, discharge 2 - 15 m³/s Six weirs with bypasschannels Targets: increase ground water level & irrigation

Danube

> 40 species!!!

BYPASS-CHANNEL WEIR 3

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Total lengths 107 m Difference of WSL 100 cm Ten basins Max. discharge 350 l/s

E ntrance directly out of the scour basin of the weir Steps built by concreteelements & wooden weirs

BYPASS-CHANNEL WEIR 4 bypass entrance

Entrance 230 Steps

o

Total length 396 m

o

Difference of WSL 170 cm

o

14 pools

o

Max. discharge 450 l/s

m downstream of weir 4

built by rip rap in concrete bed

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number of individuals

UPSTREAM FISH MIGRATION (both traps)

100000 90000 80000 70000 60000 50000 40000 30000 20000 10000 0

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89945

59837

7469

1993

1994

year

1995

EFFECTIVENESS â&#x20AC;&#x201C; FISH LADDER AT WEIR 4 â&#x20AC;&#x201C; upstream migration versus downstream population

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Zingel zingel, n = 8 Stizostedion lucioperca, n = 35

1:5 1:3

N = 57,806

Scardinius erythrophthalmus, n = 1806

301 : 1

Rutilus rutilus, n = 10,764

211 : 1 45 : 1

Perca fluviatilis, n = 2277 Leuciscus leuciscus, n = 392

392 : 1 35 : 1

Leuciscus idus, n = 532 Leuciscus cephalus, n = 462 Lepomis gibbosus, n = 40 Hybrid, n = 172 Gobio gobio, n = 2068 Gobio albipinnatus, n = 63 Chondrostoma nasus, n = 333

3:1 20 : 1 43 : 1 20 : 1 32 : 1 67 : 1 23 : 1

Carassius auratus gibelio, n = 529 Carassius auratus auratus, n = 598

16 : 1

Blicca bjoerkna, n = 274 Barbus barbus, n = 24

30 : 1 1:2

Aspius aspius, n = 756

756 : 1

Alburnus alburnus, n = 35,846

618 : 1

Abramis brama, n = 107

9:1

ATTRACTION FLOW ANALYSIS bypass - channel weir 4

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channel discharge 2000 l/s P

rop ort io

channel discharge 6000 l/s P n1

:4

bypass discharge 450 l/s

rop ort io

n1

:24

bypass discharge 250 l/s

WATER TEMPERATURE triggering up- and downstream migration (03.10. - 06.12.1997)

Downstream: 150

2202 individuals

14

19 species

12 10 8

100 6 4

50

2 0

0

downstream

6.12

4.12

2.12

30.11

28.11

26.11

24.11

22.11

20.11

18.11

16.11

14.11

12.11

10.11

8.11

6.11

4.11

2.11

31.10

29.10

27.10

25.10

23.10

21.10

19.10

17.10

15.10

13.10

11.10

9.10

7.10

5.10

3.10

upstream

Date

Temperature [째C]

16

N (total) = 4650

200

Number of fish passed .

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RESULTS

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• Passage of 40 fish species • 11 rheophilic species • 22 indifferent species • 7 stagnophilic species

• Passage of all life stages • 50 % of the most frequently caught species were juveniles

• Extensive downstream migrations (larvae and juveniles)

EFFECTIVENESS

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Passage for nearly all fish species and age classes Passage for a significant proportion of the migrating population Habitat for a site-specific fish assemblage

??

Downstream migration

Floodplain flow regulation channel system impounded Danube – re-connection of backwaters

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Gießgang Greifenstein

42 km length 25 small impoundments 4 – 1000 m3/s flow

Hydropower plant production 1,717 mil. kWh head 12.6 m max. flow 3,150 m³/s impoundment length 31 km

The EU-LIFE project „Living space of Danube salmon (Hucho hucho L.)“ General background

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Establishment of Natura-2000 Network of protected areas by the EU Projects aiming to conserve natural and wild fauna and flora of EU-interest are funded by the EU- commission Hucho hucho is one of the most endangered fish species of Europe

Ecological objectives restore and protect intact populations guarantee minimal population size enable recolonisation Prey species: Chondrostoma nasus Thymallus thymallus

Indicator species: Danube Salmon „Hucho hucho L.“ one of the largest freshwater fish species in the world (length > 140 cm, weight > 60 kg, age > 15 years) a rheophilic, gravel spawning species (March/April), with pronounced piscivorous behaviour even in the juvenile stage.

Project area

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and distribution of Hucho hucho L. in Austria Self sustaining populations Present distribution Original distribution

Danube 0

500 1000 1500 2000 2500 3000 River length [km]

Vienna n

Project area

Measures â&#x20AC;&#x201C;

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types and their spatial distribution Nr. of continuum interruptions Pielach 6 Nr. of continuum interruptions Melk 4

z

... (1) opening of river continuum ... (2) restoration of river channel and (3) purchase of land

Nr. of continuum interruptions Mank 3 5 km

Project area – river characteristics Characteristic Stream order Altitude (m aA) Gradient (‰ ) -1 Meanflow (m ³s ) Flowregim e Fishregion

Melk

Danube Pielach Melk 9 4 5 209–196 252–205 233–206 0.4 2.23 1.6 ~1900 ~6.5 ~3 ModerateW interPluv io-niv al niv al pluv ial Epipotam al

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Mank 4 270.5–233 4.6 ~0.5 W interpluv ial

Hyporhithral EpiHyporhithral /Epipotam al potam al /Epipotam al

Pielach

Mank

Conducted measures (1) 11 fish ladders ¾Types of fish ladders ¾ rock-ramps

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(2) River restoration ¾ Leitbild-orientated restoration of 2200 m regulated river channel

¾ nature like bypass channels ¾ pool and weir bypass

¾ bypassed heigths 1- 4 m ¾ channel slopes from 0.7 to 5.1 % ¾ Lenghts from 20 - 300 m ¾ discharges from 250 l to >1500 l

(3) Protection of river sections with natural dynamics ¾ Purchase of 71 ha land

Example:

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Nature like bypass-channel at river Pielach ¾ bypassed heighth: 2,8 m ¾ type: nature like bypass channel ¾ Length: 250 m ¾ slope: 1,31% ¾ min. depth: 10 cm ¾ min. discharge: ~ 500 l/sec

Example:

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Nature like rock ramp at river Pielach ¾ bypassed heighth: 1,8 m ¾ type: rock ramp ¾ Length: 34 m ¾ slope: 5.1% ¾ min. depth: 41 cm ¾ min. discharge: ~ 600 l/sec

Example:

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Nature like rock ramp at the mouth of river Melk ¾ bypassed heighth: 3.4 m ¾ type: rock ramp ¾ Length: ~ 89 m ¾ slope: 3.8 % ¾ min. depth: 29 cm ¾ min. discharge: ~ 500 l/sec

Example:

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Pool and weir fish pass at river Melk ¾ Bypassed heighth: 3.5 m ¾ Type: rock ramp ¾ Length: ~ 110 m ¾ Slope: 3.3 % ¾ Min. depth: 10 cm ¾ Min. discharge: ~ 250 l/sec

Monitoring – from 1999 to 2004

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Evaluation of total fish stock within the project area before and after implementation of the measures Evaluation of the efficiency of each individual fish ladder based on fish using a method developed with regard to the EU-water framework directive (5-level scheme, Woschitz et al. 2003) Evaluation of the fish-ecological integrity (5-level scheme) before and after implementation of the measures with regard to the EU-water framework directive (Schmutz et al. 2000) Reconstruction of the river type specific fish community

Electro-fishing

Marking

Trapping

Species Barbe Laube Aitel Brachse Gründling Nase Rotauge Güster Äsche Giebel Bachforelle Regenbogenforelle Hasel Karpfen Schneider Weißflossengründling Flussbarsch Huchen Schied Elritze Koppe Zingel Zope Zander Rotfeder Rußnase Hecht Bachsaibling Nerfling Marmorgrundel Kaulbarsch Schleie Schmerle Schrätzer Donaukaulbarsch Steinbeißer Wels Zobel Nr. of species Total nr. of individuals

FFHspecies

x x x x

x x

6

Number of individuals Melk Pielach Mank Total 953 265 7 1225 563 14 0 577 101 141 9 251 230 0 0 230 179 21 2 202 100 46 10 156 113 2 0 115 111 0 0 111 19 60 1 80 63 0 0 63 27 25 4 56 25 15 0 40 27 13 0 40 37 2 0 39 0 34 0 34 27 0 0 27 22 4 0 26 1 20 2 23 22 0 0 22 17 0 2 19 11 5 0 16 11 0 0 11 10 0 0 10 8 0 0 8 6 1 0 7 7 0 0 7 5 1 0 6 5 0 0 5 5 0 0 5 2 3 0 5 4 0 0 4 3 0 0 3 2 0 1 3 3 0 0 3 2 0 2 1 0 0 1 1 0 0 1 1 0 0 1 37 17 9 38 2724 672 38 3434

Total number of fish caugth at fish ladders

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Evaluation of river re-structuring Increase of biomass from 37 kg/ha to 920 kg/ha

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before

Increase of number of species from 6 to 12 Hucho hucho only occurs in restructured areas!

But: with regard to the river type specific community: 5 species are still lacking one year after implementation Enhancement of age distributions Enhancement of fish ecological integrity (4.1

2.6)

after

Re-connection of fragmented sub-populations e.g. of Hucho hucho

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Total re-connected population size of Hucho hucho in river Pielach now: 162 adult individuals 47 0

24 35

0 â&#x20AC;Ścontinuum interruptions xxâ&#x20AC;Śnumber of adult individuals (> 700 mm) of Hucho hucho

0 2 9

5 5

50

6

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Increase of species in river Melk 35

4 species are still lacking:

32 28

30

Carassius carassius, Cyprinus carpio, Eudontomyzon mariae, Leuciscus souffia agassizi,

Leitbild before

Number of species

after

25

23 All 10 temporal species used the re-opened continuum during the first year Abramis brama, Abramis sapa, Abramis ballerus, Blicca bjoerkna, Vimba vimba, Gymnocephalus baloni, Gymnocephalus cernuus, Gymnocephalus schr채tzer, Silururs glanis, Sander lucipoperca,

20 15

10

10

10

5 0

0 river type specific

temporal, only during spawing season

Fish ecological integrity (Schmutz et al. 2001) of river Melk – before/after implementation of the measures: only number of river type specific species and number of guilds were considered!

M1 – „Melkrampe“

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www.boku.ac.at/hfa Fish ecological integrity â&#x20AC;&#x201C; before/after implementation of the measures

1,7...1,7

3,6...3,4

2,9...2,8 2,6...2,4 Danube

Pi el ac h

3,2...2,9 M

3,1...2,7

k el

Enhancement of the fish ecological integrity weighted by river strech lenght for rivers Pielach and Melk: Pielach: from 2.6 to 2.4 (from moderate to good) M

an

k

Melk: from 3.2 to 3.0 (still moderate)

N

2,9...2,8 km

7,5

10

SUMMARY – Ecological Requirements

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• Fish are evolutionarily adopted to their living space – habitats and flow regime • They have to move between different habitats to maintain their population size and minimize mortality • Fragmentation of habitats leads to increased mortalities and a decrease of population size (due to the lack of spawning sites, habitats for larvae, winter habitat, refuge habitat…) and extinction of species

SUMMARY – Bypass channels

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• Have to re-establish the river continuum for the entire migratory fauna • All species • All live stages

• • • •

Cost saving (construction, maintenance) Adaptation to a wide range of flow regimes Riverine habitat substitution Aesthetic value (Integration into the landscape)

BUT: • Downstream migration is still a widely unsolved problem • Upstream fish passage enhances only then the fish ecological integrity, when useable habitats are available – habitat restoration has additionally to be done when necessary!!

Natural dimensions of a riverine landscape

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BOKU - University of Natural Resources and Applied Life Sciences Department of Water, Atmosphere and Environment Institute of Hydrobiology and Aquatic Ecosystem Management Andreas Zitek & Stefan Schmutz Max-Emanuelstrasse 17, A-1180 Vienna Tel.: +43 1 47654-5215, Fax: +43 1 47654-5217 Andreas.Zitek@boku.ac.at , Stefan.Schmutz@boku.ac.at www.boku.ac.at/hfa