Recovery of clear-water, macrophyte-dominated lakes: concepts and case studies

8/6/2019 Recovery of clear-water, macrophyte-dominated lakes: concepts and case studies

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9 J anuary 2004

recovery of clear-water,macrophyte-dominated lakes:concepts and case studies

Hugo Coops

RIZA Institute for Inland Water Management and Waste WaterTreatment, The Netherlands


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9 January 202

Delta of large rivers Rhine andMeuse

Hundreds of shallow lakes

Many lakes are man-made

Most lakes are strongly regulated

The Netherlands


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9 January 203

Man-made lakes


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9 January 204

Conservation: lakeNaardermeer


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9 January 205

Algal blooms


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9 January 206

P-reduction in the RiverRhine


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9 January 207

The foodweb of shallowlakes


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9 January 208

Algae

Suspendedsediment

NutrientsWater depth

Vegetation

AllelopathiccompoundsWaves

ZooplanktonFishes

Mussels

Turbidity


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9 January 209

Algae

Suspendedsediment


Vegetation


ZooplanktonFishes

Mussels

Turbidity


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9 January 2010

Limitation of phytoplanktongrowth


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9 January 2011

Algae

Suspendedsediment


Vegetation


ZooplanktonFishes

Mussels

Turbidity


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9 January 2012

Algae

Suspendedsediment


Vegetation


ZooplanktonFishes

Mussels

Turbidity


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9 January 2013

Impact of Bream ontransparency


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9 January 2014

Bream stocking experiment


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9 January 2015

Algae

Suspendedsediment


Vegetation


ZooplanktonFishes

Mussels

Turbidity


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9 January 2016

Freshwater mussels


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9 January 2017

Algae

Suspendedsediment


Vegetation


ZooplanktonFishes

Mussels

Turbidity


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9 January 2018

Aquatic vegetation

Mechanisms

- Prevention of resuspension- Competition for nutrients

- Refugium for zooplankton

- Allelopathic substances

- Effects on fish community


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9 January 2019

0.00001

0.0001

0.001

0.01

0.1

1

10

mrt apr mei jun jul aug sep okt

Concentrationcarb

on(mM

HCO3

CharaHCO3

outside

CO2CharaCO2

Macrophytes reduce C-availability


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9 January 2020

Shifts between clear andturbid


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9 January 2021

Alternative stable states


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9 January 2022

Biomanipulation

Fish removal

Daphnia escapes predation

Spring clear water phase

planktivores benthivores

Reduced resuspension

Macrophyte proliferation

Nutrientfixation

Piscivorehabitat

Suppressionof algae

Reducedresuspension

Stable clear water

Clear water

Zooplanktonrefuge


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9 January 2023

Biomanipulation cases:lake Zwemlust (1987)


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9 January 2024

The three steps ofbiomanipulation


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9 January 2025

Success of biomanipulationcases

Success = improved Secchi depth

18 cases in the Netherlands:- 16 (partially) successful

- 2 failures- 10 cases still clear after 5-10 year period

Lack of success:1. insufficient fish removal2. peaty sediment

3. high wind resuspension4. poor development of piscivores5. high nutrient concentrations6. presence of invertebrate predators


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9 January 2026

Controlling fish stock iscrucial


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9 January 2027

Biomanipulation cases:Lake Wolderwijd (1990)


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9 January 2028

Wolderwijd: Fish stock


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9 January 2029

Wolderwijd: watertransparency


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9 January 2031

Role of the littoral zone

Algae

Suspended

sediment


Vegetation

Allelopathiccompounds

Waves

ZooplanktonFishes

Mussels

Turbidity

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9 January 2032

Zooplankton migration

Horizontal migration of zooplanktonin Veluwemeer

At nighttime into the open lake (A)

At daytime inside vegetation (E)

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9 January 2033

Pike depends on inundatedemergent vegetation

0

20

40

60

80

100

120

0 20 40 60 80 100

% vegetated area

kg northern

pike / ha

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9 January 2034

Water-level fluctuations

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9 January 2035

Flooding-drawdown cycle

36W t l l i t


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9 January 2036Water-level experiment,

lake Volkerakmeer (1996-2001)

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9 January 2037

Management of trophic state

turbidity

algae

P-lake

P-inflow

Nutrient management

(emergent)vegetation

(submerged)vegetation

filter-feeders

(mussels)

filter-feeders

(zooplankton)

resuspendedsediments

Water-level

ana

gement

Fisheriesm

anag

emen

tresuspendedsediments

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9 January 2038

Veluwemeer: a lakerestoration case

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9 January 2039

Veluwemeer rehabilitationprogram

Large efforts to reduce nutrientinflow since 1979

Recovery of the clear,

macrophyte-dominated state Stability of the macrophyte

dominated state

Biodiversity associated with the

macrophyte-dominated state Effects of macrophytes on

recreation

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9 January 2040

Cyanobacteria, Charophytes,Bream and Zebra mussels

1965 1970 1975 1980 1985 1990 1995 2000

0

20

40

60

80

100

%fil

cyanobacteria

1965 1970 1975 1980 1985 1990 1995 2000

0

50

100

150

200

250

bream

(kg/ha)

1965 1970 1975 1980 1985 1990 1995 2000

0.0

0.2

0.4

0.6

0.8

1.0

charophytec

overage(-)

1965 1970 1975 1980 1985 1990 1995 2000

0

200

400

600

zebramusse

ls(n/m2)

41


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9 January 2041

Charophyte expansion (1)

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9 January 2042

Charophyte expansion (2)

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9 January 2043

Chara Potamogetonperfoliatus

Potamogetonpectinatus

pondweedscharophytes

Submerged macrophytes

44O f h t


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9 January 2044Occurrence of macrophytes

is limited by light and waterdepth

100 200 300 4001.0

2.0

3.0

4.0

100 200 300 4001.0

2.0

3.0

4.01-14 %

15-100 %

Turbidity (1/m)

Chara spp.

100 200 300 4001.0

2.0

3.0

4.0

100 200 300 4001.0

2.0

3.0

4.01-14 %

15-100 %

P. pectinatus

100 200 300 4001.0

2.0

3.0

4.0

100 200 300 4001.0

2.0

3.0

4.0

1-14 %

15-100 %

P. perfoliatus

turbidity(1/m)

depth (m)

Potamogeton pectinatus Chara species Potamogeton perfoliatus

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9 January 2045

0

200

400

600

800

1000

1200

1400

1600

19691972197519781981198419871990199319961999

hainternalcover

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

doorzicht(dm) kranswier

Doorgroeid Fonteinkruid

Schedefonteinkruid

doorzicht

Charophytes

Potamogeton perfoliatus

Potamogeton pectinatus

transparency

Macrophytes andtransparency

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9 January 2046

Clear water

Nutrients

Algae

Zooplankton

Zooplanktivorous

fish

Predatory fish

Benthivorous fish

Resuspension

Waves

Sedimentation

Water plants

-

-

-

-

-

--

--

-

-

-

+

+

+

+

+

+

+

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9 January 2047

Stability of themacrophyte-dominated state

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9 January 2048

0%bedekking

>75%

bedekking

0.0

0.2

0.4

0.6

0.8

1.0

3.0

0.0

0.2

0.4

0.6

0.8

1.0

depth / transparency (-)

3.0

0 % 0-1 % 1-5 % 5-15%

15-25% 25-50% 50-75% 75-100%

0%Chara-cover

> 75%Chara-cover

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9 January 2049

mac

rophyt

es

Plake

chlorophyll-a

transparency

externalP-loading

(depth/ transparency)

enhanced

retention

grazer refuge,allelopathy a.o.

reduced

resuspension

Empirical model

50

Gesimuleerde tijdseries van de Chara


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9 January 2050

low

intermediate

high

Gesimuleerde tijdseries van de Charabedekking bij drie niveaus P-belasting

0

0.2

0.4

0.6

0

0.2

0.4

0.6

cha

rophytecovera

ge(-)

0

0.2

0.4

0.6

time

Simulations of Chara-cover at three levels of P-loading

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9 January 2051

clear alternative states turbid

Kans op de troebele of heldere toestand inrelatie tot P-belasting

2 4 6 8 10 12

0.0

0.2

0.4

0.6

0.8

1.0

P-loading factor (-)

P(turbi

d)(-)

P(clear) P(turbid)

Probability of clear and turbid water

52

h d l di


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9 January 2052

macrophytes

nutrient loading

redrawn from:Scheffer (1998)

Chara bedekking in relatie tot nutrientenbelasting

2 4 6 8 10 12

0.0

0.1

0.2

0.3

0.4

0.5

0.6


charo

phyte

coverage

(-)

clear water state turbid state

Chara-cover and P-loading

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9 January 2053

Gecombineerd effect van nutrientenbelasting en

peilbeheer

0 2 4 6 8 10 12-0.1

-0.0

0.1

0.2


changeinwa

terlevel(m)

turbid water

alternative

clear waterstable

states

Combined effect of nutrient loading and water level

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9 January 2054

Biodiversity of themacrophyte-dominated state

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9 January 2055

Water birds in Veluwemeer

PiscivoresGreat crested grebe, Cormorant, Smew*,Goosander

Benthivores

Tufted duck*, Pochard*, Coot* (winter),Goldeneye

HerbivoresMute swan*, Bewicks swan*, Coot* (autumn),Pintail*, Red-crested pochard, Gadwall*, Teal,

Wigeon

* exceeding 1% of W-palearctic population(Ramsar criterium)

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9 January 20

0

10000

20000

30000

40000

50000

60000

1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997

Mosseleters

Planteneters

Viseters

Molluscivores

Herbivores

Piscivores

Food guilds of water birds

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9 January 20Piscivorous birds

9 2058


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9 January 20

0%

20%

40%

60%

80%

100%

64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98

%b

iomassa

Brasem >24cmBrasem 15-24cm

Brasem 24 cm

Bream 15-24 cm

Bream


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9 January 20

0

100

200

300

400

500

600

700

1964 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000

0

2

4

6

8

10

12

AalscholverFuut

Nonnetje

Grote Zaagbek

doorzicht

CormorantGreat crested grebeSmewGoosander

transparency

Piscivores and transparency

9 J 2060Benthivorous water birds


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9 January 20Benthivorous water birds

9 J 2061

f


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9 January 20

0

2000

4000

6000

8000

10000

12000

14000

16000

1957 1962 1967 1972 1977 1982 1987 1992 1997

0

50

100

150

200

250

300

350

Brilduiker

Kuifeend

Tafeleend

mosselen

GoldeneyeTufted duckPochardmussels

Benthivores and freshwatermussels

9 J 2062Herbivorous water birds


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9 January 20Herbivorous water birds

9 J 2063


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9 January 20Herbivores and Chara

9 J 2064

R t ti Ch


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9 January 20

0

500

1000

1500

2000

2500

1957 1960 1963 1966 1969 1972 1975 1978 1981 1984 1987 1990 1993 1996 1999

0

5000

10000

15000

20000

25000

30000

Chara oppervlak

Graasdruk

Chara area (ha)Grazing pressure (kg bird)

Reconstruction Chara-covered area

9 J 2065


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9 January 20

0

5000

10000

15000

20000

25000

30000

1957 1960 1963 1966 1969 1972 1975 1978 1981 1984 1987 1990 1993 1996 1999

Pijlstaart

Kleine Zwaan

Krooneend

Meerkoet

Knobbelzwaan

Pintail

Bewicks swan

Red-cr. Pochard

Coot

Mute swan

Grazing pressure

9 January 2066

F i d th i l ti t


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9 January 20

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

waterdepth (cm rel. to winter level)

%o

fmaximum

nu

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

Charabiom

Kranswier

Wintertaling

Pijlstaart

Knobbelzwaan

Chara

Teal

Pintail

Mute swan

Foraging depth in relation toChara-distribution

9 January 2067


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9 January 20Water-level fluctuations

9 January 2068


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9 January 20

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1-sep-99 6-okt-99 10-nov-99 16-dec-99 19-jan-00 23-feb-00 26-apr-00

nr.ofMallards

-40

-30

-20

-10

0

10

20

waterlevel(cma.s.l.)

Mallard duck and water level

9 January 2069


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9 January 20

Effects of macrophytes on recreation

9 January 2070


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9 January 20

0

25

50

75

100

25

75

125

175

225

275

325

375

425

475

0

2

4

6

8

10

12

P. perfoliatus

Chara

Nuisance vegetation

9 January 2071

Macrophyte cutting


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9 January 20Macrophyte cuttingexperiment

9 January 2072


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9 January 20Thanks

Rob Portielje

Marcel van den Berg

Ruurd Noordhuis

Regional Directorate the IJ sselmeer Region

Regional Directorate Zeeland

Dutch Lake Restoration Platform

Documents

Recovery of clear-water, macrophyte-dominated lakes: concepts and case studies