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University of Amsterdam

Faculty of Science

Wageningen University and Research Centre

Alterra Research Institute

Climate Change & Adaptive Land & Water

Management

Taking the bite out of ‘de Peel’;

Determination of the environmental conditions

that sustain high numbers of Aedes cinereus larvae

in the peat bog areas surrounding Griendtsveen.

Bachelor Thesis

Brian Wals

Supervisor:

Dhr. prof. dr. ir. Piet Verdonschot

(2)
(3)

Abstract

The town of Griendtsveen (NL) has been exposed to a mosquito nuisance for the past

years and Aedes cinereus has found to be the most abundant mosquito species within

this region. Though research has been done locally on numbers of mature mosquitos,

there is little known about the mosquito larvae and their preferred habitat. This

research aimed to find out what environmental conditions sustain high numbers of

Aedes cinereus larvae. This was done by acquiring data via fieldwork over a period of

6 weeks in the peat bog area surrounding Griendtsveen and subsequently conducting a

statistical analysis of models based on this data. Results showed with a reliability of

39.52% that with regard to substrate content: leaves, mosses, wood, algae and grass

correlated with the number of Aedes cinereus larvae found; as did trees, high grasses

and low grasses with regard to vegetation type. Furthermore, with regard to water

cover, mosses showed a correlation and the variables: DO content, water temperature

and water depth did as well. These new insights can be used for mitigation of the

nuisance or form the basis for further research on this species.

(4)
(5)

Contents

1. Introduction ...1

1.1. Research question ...2

1.1.1. Research sub-questions ...2

1.2. Aim of the research ...2

1.3. Hypothesis ...2

2. Material & Methods ...3

2.1. Peatland surrounding Griendtsveen ...3

2.2. Data ...4

2.2.1. Mosquito larvae numbers ...4

2.2.2. pH, conductivity, dissolved oxygen concentration and water temperature ...5

2.2.3. Water depth ...5

2.2.4.

Substrate content and properties, vegetation cover and type, water cover and

weather.

...6

2.2.5. Water colour ...6

2.3. List of materials ...7

3. Results ...7

3.1. Environmental conditions ...7

3.2. Aedes cinereus catches ...7

3.3. Correlation between number of Aedes cinereus larvae found and environmental conditions ...8

4. Discussion ...11

5. Conclusion ...11

6. Acknowledgements ...12

References ...12

Appendix

A. Template for digital data copy ...13

B. Newspaper article ‘de Limburger’ (May 28th, 2016) ...14

C. R-code for statistical analysis ...15

D. Master Dataset ...17

(6)

1. Introduction

The town of Griendtsveen, located on the

border of the provinces Noord-Brabant and

Limburg, has in recent years experienced

nuisance by mosquitos. The mosquito

population is for the greatest part made up

by marsh mosquitos (82%) and particularly

by the species Aedes cinereus (72%)

(Verdonschot et al., 2015). The most likely

reason for the increase in mosquito

numbers is the hydrological measures

taken to improve the nature quality for peat

formation and the accompanying formation

of temporal pools (Knotters et al., 2008).

This development mainly consists of water

level rise by filling up ditches and trenches

and closing canals to recreate peatland.

This peatland now functions as breeding

places for marsh mosquitos. Breeding

locations for marsh mosquitos are typically

characterised by shallow, isolated, seasonal

waters containing a high amount of organic

material, low oxygen levels and thus few

predators.

This research aimed to find out under what

conditions most of the Aedes cinereus

mosquitos originate within the peatland.

This was done by checking if certain

environmental conditions could be linked

to

mosquito

larvae

numbers.

Environmental conditions that were taken

into account in this research are: dissolved

oxygen, pH, conductivity, colour, substrate

type, and water temperature and depth. For

this research data was ascertained by

conducting field work. This field work was

done during the period of April 19

th

measuring a multitude of environmental

parameters.

Very little previous research has been done

on Aedes cinereus mosquitos. Previous

research that has been done in this area

was conducted by Alterra Research

Institute and investigated the mosquito

nuisance as a whole. This included the

monitoring of the nuisance, an indication

of to what extent the nuisance was present

and advice with regard to the effects of

measures that were taken. The research

confirmed what species of mosquitos were

present in the area and to what extent each

species was present. It was also concluded

that the range of the mosquitos was 1.5 –

2km (Verdonschot et al., 2015).

Furthermore Verdonschot et al. (2015)

stated that the Aedes cinereus sucks blood

from mammals and birds. Also they note

that eggs are deposited in the period of

June-September in low lying regions that

flood in periods of rain and that, on

average, 60 eggs are laid at a time. The

eggs hatch in April, regardless of whether

they are submerged in water earlier on or

not.

This research provides new insights by

being able to predict breeding locations

within a peatland area. Also it can form the

basis for further research or for the

mitigation of nuisances formed by Aedes

(7)

1.1

Research question

What environmental conditions determine

Aedes cinereus larvae number in the peat

bog area surrounding Griendtsveen?

1.1.1 Research sub-questions

1. Which environmental conditions

are present in the peat bog area

surrounding

Griendtsveen?

.

2. Where are most Aedes cinereus

found in the peat bog area

surrounding

Griendtsveen?

.

3. Is there a correlation between the

number of Aedes cinereus larvae

found at a location and the

environmental conditions that are

present?

1.2 Aim of the research

The main objective of this research was to

gain insight in the relation between number

of Aedes cinereus larvae present within a

location and the environmental conditions

that are present within that same location.

This research can be used in order to

predict the number of Aedes cinereus

larvae within an area based on present

environmental conditions thus making it

easier to assess population size. Insights

can be used for further research regarding

the Aedes cinereus or for the mitigation of

nuisances formed by Aedes cinereus.

1.3 Hypothesis

that high numbers of Aedes cinereus larvae

will be present in locations that contain

shallow water and have low concentrations

of dissolved oxygen (Verdonschot et al.,

2015). Shallow water is expected to

correlate with higher water temperatures

which are favourable for the development

of the larvae as they are

(meso-)thermophilic (Verdonschot et al., 2015).

Low concentrations of dissolved oxygen

may cause fewer predators to be present

and are expected to be the result of large

amounts of organic material on the bottom

of the water (Verdonschot et al., 2015).

Because

Aedes

cinereus

is

slightly

acidophilic it is expected that they are

more common in water with pH levels < 7.

Due to the fact that there is very little

scientific knowledge available about the

Aedes

cinereus

it

is

unknown

if

conductivity will have any influence on

larvae number. It is however expected that

fewer Aedes cinereus larvae will be present

in water that has high amounts of moss or

algae cover.

(8)

2. Material &

Methods

2.1. Peatland surrounding Griendtsveen

‘De Peel’ is a region in the Southeast of the

Netherlands located on the border of the

provinces of North-Brabant and Limburg.

The region is best known for peat

extraction, a process that had been going

on since the Middle Ages but is currently

no longer done. The region is characterized

by many canals, which were dug for the

purpose of peat extraction. The exact

locations of the peatbog area that were

researched

are:

Deurnsche

Peel,

Kanaalbos,

Grauwveen

and

the

compartments Driehonderd

Bunders and Horster Driehoek within the

Mariapeel. All these locations are within a

2

km

radius

from

the

town

of

Griendtsveen, which has experienced a

considerable mosquito nuisance over the

past years.

The region has undergone some changes as

measures were taken that coincide with the

LIFE+ project. The LIFE+ project is the

European Union’s nature conservation

financial instrument which is used for the

conservation of Natura 2000 areas.

Conservation efforts are commissioned by

Staatsbosbeheer and carried out with

financial support from LIFE+ and the

province Limburg. Measures that have or

will be taken consist of creating shallower

(9)

water bodies, the installation of quays,

deforestation of circa 8 ha of woods, an

increased overall water level, further

partitioning of the area and the installation

of a dry compartment.

Current environmental conditions in the

region vary greatly dependent on the

amount of water that is present. Large

bodies of water alternate with forests that

vary in denseness. Vegetation in the area

consists mostly out of purple moor-grass

(Molinia caerule), the grass-like plant

Juncaceae Juncus effucus, commonly

known as pitrus, and woods consisting

mostly out of birch (Betulaceae Betula)

trees. In addition: the dominant moss

species in the area consists of the genus

Sphagnum, commonly known as peat

moss. Heather is also present in certain

areas, as is colonial bent (Agrostis

capillaris

).

2.2. Data

The data used for this research were

acquired between the 19

th

of April and the

27

th

of June by fieldwork. Fieldwork was

carried out by Keizer (2016), De Meyer

(2016) and Wals (2016) as their bachelor

theses required the same type of data.

Accommodation was provided by Alterra

in the town of Griendtsveen in order to

maximize efficiency during the timeframe

of the research. During the research period

59 locations were sampled either once or

twice. For the sake of convenience a

cinereus was determined for each location

as were the environmental conditions:

dissolved oxygen (DO), pH, conductivity,

colour, substrate content, vegetation cover

and water depth. Different methods were

used for every parameter. A digital copy of

the acquired data was made according to

the spreadsheet found in appendix A

Parameters and accessory measurement

methods that are relevant for this research

will now be addressed and a list of

materials that were used can be found in

subsection

2.3.

2.2.1. Mosquito larvae numbers

For the larval survey a white plastic dipper

equipped with a long solid aluminium

handle, also known as a Clarke dipper, was

used. While operating the Clarke dipper

there are several dipping techniques that

can be appropriate. The dipping methods

that were used during this research were

classified by O’Malley (1995) as ‘partial

submersion’ and ‘flow-in’. Which method

was used per location depended on the

water depth that was present. According to

O’Malley (1995) during partial submersion

“the dipper is submerged at approximately

45° along the emergent vegetation. Water

flows rapidly into the dipper. The dipper is

not moved horizontally. The dipper can be

moved vertically to scrape along the edge

of emergent vegetation.” Flow-in on the

other hand “is used in shallow water that

has a depth < the height of the ladle on the

dipper. The bottom of the dipper is pushed

(10)

During sampling an effort was made to

approach the site while facing the sun,

moving vegetation only when necessary

and using quit slow steps. This was done in

order to minimize disturbance of the water

surface as disturbance will stimulate

immature mosquitos to dive from the water

surface (Workman and Walton, 2003)

After a sample had been taken the water

was undone from larger organic material

and subsequently was poured through a

screen. This left the larvae exposed thus

making it easier to place them into the

container that was designated to the

location. This placement was done making

use of tweezers. The container was a

plastic bottle was partially filled with

alcohol in order to simplify species

determination. Species determination was

carried out by Alterra Research Institute at

their lab in Wageningen.

2.2.2. pH, conductivity, dissolved oxygen

concentration and water temperature

Dissolved oxygen concentration and water

temperature were measured in the field

with a Hach Sension 156 Portable

multiparameter meter. This was done by

taking a water sample with the Clarke

dipper and placing the DO probe and

temperature probe in it.

The pH and conductivity were also

measured with a Hach Sension 156

Portable multiparameter meter. However,

they were not measured in the field

because it was a very time consuming

process. Therefore water samples were

completed. All values given by the meters

were rounded up or down to 2 decimal

places for practical reasons.

2.2.3. Water depth

Water depth was measured by a ruler.

During the measurements the ruler was

lowered into the water until the bottom was

reached. No additional pressure was

exercised upon the stick so that the first

bottom was the one measured. Additional

water underneath a potential false bottom

was not taken into account. Measurements

were rounded up to a multitude of 5 cm to

prevent

unjustified

accuracy

from

occurring.

Image 2.2: A Hach Sension 156 Portable

multiparameter meter with DO probe

attached to it. (

www.coleparmer.com

)

(11)

2.2.4. Substrate content and properties,

vegetation cover and type, water cover

and weather.

When assessing substrate content and

properties a scale of 0-5 was used to

quantify the data. The values 0-5 can be

interpreted as followed: 0 = 0-5%, 1 =

5-20%, 2 = 20-40%, 3 = 40-60%, 4 =

60-80%, 5 = 80-100%. The assessment of the

substrate was done by ‘digging’ into the

soil with the Clarke dipper and exposing

the content on the surface besides the

water. Subsequently, the substrate was

valued through estimation by sight for the

following

vegetation

related

characteristics: leaves, wood, water plants,

mosses, algae and grass. After the content

had been determined the substrates

properties with regard to the extent of its

decay were assessed. This was done by

valuing the percentage of fine particulate

organic matter (FPOM) and coarse

particulate matter (CPOM) that the

substrate consisted of. This was also done

by means of estimation by visual

observation.

The same method was used to determine

the vegetation cover. Vegetation cover was

estimated for: trees, bushes, heath, high

grasses, low grasses and mosses. Water

cover was subsequently determined by

estimating the percentage of mosses and

algae present on the water surface and

placing them in the scale of 0-5.

Weather was monitored in order to account

wind was present and, if present, sunshine

or

rain.

2.2.5. Water colour

In order to determine the colour of the

water a sample was taken at every location

in a clear plastic container. When all

locations had been sampled the containers

were aligned and categorized on a scale of

1-3. This was done under even lighting

conditions to avoid. Examples of colours

that the samples could have can be found

in image 2.3 where: 1 = very light, 2 =

light, 3 = dark, 4 is very dark. The

categories should be interpreted as

followed: category 1 = the colour of the

locations water sample lies between

example 1 and 2, category 2 = the colour

of the locations water sample lies between

example 2 and 3, category 3 = the colour

of the locations water sample lies between

example 3 and 4.

Image 2.3. The 4 examples of water

samples used to determine category of

water colour with: 1 = very light, 2 =

light, 3 = dark, 4 is very dark.

(12)

2.3 List of materials

The table below lists all the instruments

used during the research. Instruments such

as the Clarke dipper, tweezers, sieve,

waders, measuring stick, GPS-meter, Hach

pH/DO were used frequently in the field.

Mobile phones equipped with a camera

and the Collector application for Android,

which were used as well and bicycles were

used as mean of transportation. Plastic

containers were either used to take a water

sample of a location or they were filled

with 75% ethanol, in which case they were

used to contain larvae. Plastic containers

could be washed in order to make them

available for further use again.

Item

Amount

Clarke Dipper (350 mL)

2

Tweezers

2

Sieve (Diameter!!!!)

2

Plastic cups (50 mL)

150

Waders

3

Flora book

1

Measuring stick

2

Jar with 75% ethanol

1

GPS-meter

1

Bike

3

Camera/mobile phone

3

Hach pH

1

Hach DO

1

Collector – Android mobile application

3

3. Results

3.1. Environmental conditions

Environmental

conditions

that

were

measured in this research consisted out of:

dissolved

oxygen,

pH,

conductivity,

colour,

substrate

type,

and

water

temperature and depth. In order to answer

the

first

sub-question:

‘Which

environmental conditions are present in the

peat bog area surrounding Griendtsveen?’

this research’ findings with regard to these

conditions will now be discussed. The

Dissolved oxygen content was found to be

5.42mg/L on average with a minimum

close to anoxic conditions at 0.80mg/L at

location 47 and a maximum of 13.00mg/L

at location 36.

The pH fluctuated between very acidic

(3.30) at location 39 and slightly alkaline

(7.20) at location 56. On average the pH of

the sample sites was 4.47.

After having excluded the outliers,

-1.4µS/cm at location 56 and 511µS/cm at

location 52, the mean conductivity was

(13)

and the highest measurement was found at

location 39 with 224µS/cm.

The colour of the water varied between

very light and very dark (image 2.3). Out

of the 77 water samples that were taken it

occurred 23 times that water colour was

classified to be somewhere between very

light and light. In 35 instances colour was

classified to be between light and dark in

and in the remaining 19 cases the water

colour was found to be between dark and

very dark.

Water temperature had a mean of 15.34

ͦC.

Measurements

fluctuated between a

minimum of 6.10 ͦC on April 26

th

at

location 11 and 23.10

ͦC on May 11

th

at

location 43.

Average depth of the dipping locations

ranged between 7.86cm at location 38, a

depth lesser than the height of the ladle

thus making it necessary to apply the flow-

in method, and 45.00cm at location 33.

The mean depth of all dips was 16.15cm.

3.2. Aedes cinereus catches

During this research a total of 2199

mosquito larvae were caught. As shown in

chart 3.1 our species accounted for 99% of

the total catch: Ochlerotatus sp. (6%),

Ochlerotatus cantans/annulipes (16%),

Ochlerotatus puntor (27%) and Aedus

cinereus (50%).

Because this study focussed solely on

Aedes cinereus were caught. Amongst the

50 assessments where larvae were caught

22 assessments had >10 catches. The

abundance of larvae, as well as the exact

locations of these specific assessments and

accessory information about them can be

found in chart 3.2, image 3.1 and table 3.1.

3.3. Correlation between number of

Aedes

cinereus

larvae

found

and

environmental conditions

In order to determine if a correlation was

present between environmental conditions

and number of Aedes cinereus larvae found

statistical tests were done in R-Studio. A

Shapiro-Wilk test showed that only the

data for water temperature was likely to be

distributed normally. The data for the

following variables was not distributed

normally as p <= 0.05: larvae catch

(p=2.2e-16), oxygen (p=0.00236), average

water depth (p=1.08e-09) and conductivity

(6.001e-09). Because transformations in

the form of log10, square root or arcsine

did not result in normally distributed data

and catch data was found to be Poisson

distributed a Poisson general linear model

(GLM) was used to test a correlation.

These models were made in compliance

with De Meyer as his research required a

similar model.

GLM’s containing different combinations

of variables, including variables that are

not elaborated upon in this research, were

tested for reliability based on their AIC

(14)

within R-Studio, can be found in appendix

C. Outcomes, based on the Δ AICc,

showed that 5 (0.46) and 6 (0.00)

suggested substantial evidence for the

model as they were < 2 (Burnham and

Anderson, 2002). Analysis of these models

indicated that model 5 had a probability of

44% to be the best model among the

candidate models where model 6 had a

probability of 55%. The results of model 5

and 6 will now be presented.

Model 6, which most evidence was

suggested for and which had the highest

probability of being the best model among

the candidate models, contained the

following variables: substrate: all types,

vegetation cover: trees, high grasses and

low

grasses,

water

cover:

mosses,

measured: oxygen, water temperature and

water depth. The AIC value of this model

was 1606.8 and the reliability was found to

be 39.52% (1 – (null deviance/residual

deviance)). All variables, besides substrate

leaves (p=0.005201), vegetation trees

(p=0.001578) and vegetation high grasses

(p=0.002852)

contributed

very

Model 5 contained the same variables as

model 6 but additionally contained ph. For

this model there was slightly less evidence

suggested than for model 6 and it also had

a slightly lesser probability of being the

best model among the candidate models.

Model 5 had an AIC value of 1606.2. The

contribution of every variable, besides

substrate leaves (p=

0.003143), vegetation

high grasses (p=

0.003193) and ph (p=

0.101243), to this AIC was very significant

(p<=0.001).

127 347

600 1105

Mosquito catches per species (#)

other Ochlerotatus sp. Ochlerotatus cantans/annulipes Ochlerotatus puntor Aedus cinereus

Chart 3.1.

Overview of mosquito species

that were caught and the abundance that

they were caught in.

Table 3.2: Summary output of model 6.

(15)

Chart 3.2. A column chart

containing every sample location

with an Aedes cinereus catch >1 0.

Image 3.1. Visualization of the

locations where >10 Aedes

cinereus larvae were caught.

Table 3.1. Details about the

locations that had an Aedes

cinereus catch >10.

131

105

98

82

54 54

48 46

40 39

34 33 33

26 26 23 23

18 16

11 11 11 10

0

20

40

60

80

100

120

140

27

.0

4.0

43

.0

7.0

4.1

32

.0

26

.0

38

.0

31

.0

11

.1

8.0

39

.0

42

.0

41

.0

51

.0

44

.0

50

.0

16

.0

41

.1

15

.0

27

.1

58

.0

45

.0

lar

vae

c

atc

h

Location number

Larvae catch per location (n>10)

location # Larvae catch (#) RD Coordinates Time

Date

27,0 131 191318, 383540 14:00 10-05-16 4,0 105 192933, 383342 15:05 20-04-16 43,0 98 190512, 383504 14:30 11-05-16 7,0 82 192100, 381656 11:01 21-04-16 4,1 54 192907, 383349 11:00 12-05-16 32,0 54 191745, 383266 11:00 10-05-16 26,0 48 191271, 383589 13:00 09-05-16 38,0 46 190288, 382165 16:20 10-05-16 31,0 40 191270, 383322 17:00 10-05-16 11,1 39 188610, 383500 10:40 26-05-16 8,0 34 191937, 381890 13:12 21-04-16 39,0 33 190460, 383379 11:00 11-05-16 42,0 33 190557, 383540 13:30 11-05-16 41,0 26 190623, 383492 12:15 11-05-16 51,0 26 191644, 382597 15:40 12-05-16 44,0 23 190003, 383091 16:00 11-05-16 50,0 23 191965, 382983 14:15 12-05-16 16,0 18 190273, 382904 15:45 02-05-16

(16)

4. Discussion

While conducting the research it wasn’t

always possible to ascertain data for all

parameters. Especially early on in the

research it took some time to become

acquainted with the measuring methods

and build-up. This resulted in the absence

of conductivity data until location 22. Due

to the fact that conductivity data was

unlikely to significantly fluctuate within a

relatively short time span (Verdonschot,

personal communication, May 2016) every

location that missed data was assessed a

second time and accessory data was used

for the locations. Besides conductivity,

during this research the DO probe was at

times

irresponsive

thus

making

it

impossible to test the water sample for DO

and water temperature at those times.

Furthermore it should be noted that there

were instances where a location could not

be assessed a second time due to the fact

that the site had fallen dry. If data was

unavailable for a first assessment this

resulted in incomplete data for these

locations.

In the case of missing data with regard to

substrate content, vegetation cover and

type, and water cover, estimations were

made during a second assessment or based

on the photograph taken during the first

assessment. These estimations are not as

accurate as on site estimations.

Subsequently, the dipping technique and

site conditions have played a very large

role during this research. Mosquito larvae

are very easily startled and therefor the

When working in march-like conditions it

can be difficult to leave the water

undisturbed. Also weather conditions such

as precipitation or temperature can result in

unrepresentative catches at locations. It is

also possible that mosquito larvae have a

preferred micro-habitat within an assessed

location. Though dips were taken at

random within a location the exact amount

of times that certain micro-habitats were

dipped in could have influenced the catch

as well.

The statistical analyses that were carried

out showed a reliability of respectively

39.52%. This is a very limited percentage

and thus conclusions drawn based on these

results should be made with caution. Also

noteworthy is that the statistical analysis

was only carried out for locations with

complete data for all variables used:

resulting in a total of 75 locations. It is

very well possible that other statistical

tests, unknown to me or my supervisors, fit

the acquired data in a more suitable

fashion.

5. Conclusion

According to the statistical analyses of

models 5 and 6 it can be concluded with a

reliability of 39.52% that correlations are

present between Aedes cinereus catches

and

the

following

environmental

conditions: substrate: leaves, mosses, wood

algae and grass, vegetation: trees, high

grasses and low grasses, water cover:

mosses, and the variables: DO content,

water temperature and water depth. Due to

the fact that the environmental variables:

(17)

concluded that they did not contribute to an

increased and more reliable correlation

model.

It is of great importance for further

research that data is acquired on a greater

scale and over a longer period of time in

order to adequately portray the exact

correlations existent between mosquito

larvae

number

and

environmental

conditions present within the sample site.

6. Acknowledgements

I am highly thankful to Alterra Research

Institute, Wageningen University and

Research and the University of Amsterdam

for providing the possibility and resources

to conduct this research. I would like to

thank Piet Verdonschot for familiarizing

me with the subject and his feedback

throughout the project. Also I would like to

thank Dorine Dekkers for her constant

guidance throughout the field work process

and her extensive work on species

determination in the lab. With regard to the

statistical analysis I would like to thank

Peter Roessingh and Emiel van Loon for

their consultancy. Furthermore I would

like to thank Roos Keizer and Alex de

Meyer for their full-time assistance in

acquiring data and Mario van Ooij & Els

van Geffen for hosting us during the period

of

fieldwork.

References

Anderson, D. R., & Burnham, K. P.

(2002).

Avoiding

pitfalls

when

using

information-theoretic methods. The Journal of

Wildlife Management, 912-918.Crans, W. J.

(2004). A classification system for mosquito

life cycles: life cycle types for mosquitoes of

the northeastern United States. Journal of

Vector Ecology, 29, 1-10.

Knotters, M., van Delft, S. P. J.,

Keizer-Vlek, H. E., Jansen, P. C., von Asmuth,

J. R., Sival, F. P., & van‘t Klooster, C. E.

(2008). Evaluatie monitoring Deurnese Peel en

Mariapeel. Kwantificering van effecten van

maatregelen

en

advies

over

het

monitoringsplan.(Evaluation monitoring of

Deurnese Peel and Mariapeel. Quantifying the

effects of the measures and advice about the

monitoring plan) Alterra Wageningen,

Alterra-rapport, 1717.

O’Malley, Claudia. "Seven ways to a

successful dipping career." Wing Beats 6.4

(1995): 23-24.

Verdonschot, Piet F.M., Dorine D.

Dekkers, Anna A. Besse-Lototskaya, 2015.

Stekende insecten Griendtsveen; Situatie 2015.

Wageningen,

Alterra

Wageningen

UR

(University & Research centre),

Alterra-rapport 2680. 60 blz.; 19 fig.; 9 tab.; 11 ref.

Workman, P. D. and W. E. Walton.

2003. Larval behavior of four Culex (Diptera:

Culicidae)

from

treatment

wetlands

in

southwestern United States. Journal of Vector

(18)

Appendix A: Template for digital data copy

Location: Date:

# Larvae catch (#) Acidity (pH) O₂-content (mg/L) Water temp ( ͦC) Depth (cm) Con (uS/cm) 1 2 3 4 5 6 7 8 9 10 average: GPS: Time: CPOM FPOM leaves wood waterplants mosses algae grass trees bush heath high grasses low grasses mosses mosses algae sunshine partial overcast overcast no wind little wind wind rain width (m) length (m) avarege depth (cm) water cover (%)

estimated total volume (m3) Colour (scale 1-4): Turbidity (mm)

Location image:

Vegetation (scale 1-5): Substrate (scale 1-5):

Water cover (scale 1-5):

Weather (0=no, 1=yes):

Dimensions:

(19)
(20)

Appendix C: R-code for statistical analysis

install.packages("AICcmodavg")

library(AICcmodavg)

model_list <- list()

For fill of model list see next page: List of General Linear Models (GLM) and

accessory variables.

Modnames = c("Nullmodel", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12",

"13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27",

"28", "29", "30")

aictab(model_list,modnames = Modnames)

K

AICc

Δ AICc

AICcWt

Cum.Wt LL

6 13

1613.08 0.00

0.55

0.55

-790.40

5 14

1613.54 0.46

0.44

0.99

-789.09

4 17

1621.11 8.03

0.01

1.00

-787.89

26 14

1624.07 10.99

0.00

1.00

-794.35

23 15

1640.81 27.73

0.00

1.00

-801.12

21 11

1647.27 34.19

0.00

1.00

-810.44

7 10

1647.80 34.72

0.00

1.00

-812.09

14 11

1654.87 41.79

0.00

1.00

-814.23

27 14

1657.55 44.47

0.00

1.00

-811.09

24 14

1665.10 52.02

0.00

1.00

-814.87

16 11

1678.20 65.12

0.00

1.00

-825.90

25 15

1678.69 65.61

0.00

1.00

-820.06

8 14

1696.10 83.02

0.00

1.00

-830.36

20 9 1

698.50

85.42

0.00

1.00

-838.80

28 13

1700.36 87.28

0.00

1.00

-834.04

15 11

1700.58 87.50

0.00

1.00

-837.09

30 13

1723.32 110.24

0.00

1.00

-845.52

13 11

1724.05 110.97

0.00

1.00

-848.83

17 11

1758.98 145.90

0.00

1.00

-866.29

19 10

1768.82 155.74

0.00

1.00

-872.61

10 12

1779.23 166.15

0.00

1.00

-874.97

12 11

1784.47 171.38

0.00

1.00

-879.03

11 11

1796.12 183.04

0.00

1.00

-884.86

29 13

1815.38 202.30

0.00

1.00

-891.55

22 11

1831.99 218.91

0.00

1.00

-902.79

9 5

1850.49 237.41

0.00

1.00

-919.79

18 10

2104.87 491.79

0.00

1.00

-1040.63

3 3

2405.26 792.18

0.00

1.00

-1199.45

2 2

2434.45 821.37

0.00

1.00

-1215.14

(21)

List of General Linear Models (GLM) and accessory variables:

model_list[[1]] = glm(larvaenormal ~ 1, data=dataallesclean, family = 'poisson' ) #null model with just a constant model_list[[2]] = glm(larvaenormal ~ SUBleaves, data=dataallesclean, family = 'poisson')

model_list[[3]] = glm(larvaenormal ~ SUBleaves + VEGIhigh.grasses, data=dataallesclean, family = 'poisson') model_list[[4]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + VEGImosses + WCmosses + WCalgae + ph + oxy + temp + depth + con, data=dataallesclean, family = 'poisson')

model_list[[5]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + WCmosses + ph + oxy + temp + depth, data=dataallesclean, family = 'poisson') model_list[[6]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + WCmosses + oxy + temp + depth, data=dataallesclean, family = 'poisson')

model_list[[7]] = glm(larvaenormal ~ SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGIlow.grasses + WCmosses + oxy + temp + depth, data=dataallesclean, family = 'poisson')

model_list[[8]] = glm(larvaenormal ~ SUBleaves + SUBwood + SUBgrass + VEGItrees + VEGIhigh.grasses +

VEGIlow.grasses + VEGImosses + WCmosses + WCalgae + ph + oxy + temp + depth, data=dataallesclean, family = 'poisson') model_list[[9]] = glm(larvaenormal ~ ph + oxy + temp + depth, data=dataallesclean, family = 'poisson')

model_list[[10]] = glm(larvaenormal ~ SUBleaves + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGImosses + WCmosses + WCalgae + ph + oxy + temp + depth, data=dataallesclean, family = 'poisson')

model_list[[11]] = glm(larvaenormal ~ SUBleaves + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGImosses + WCmosses + WCalgae + ph + oxy + temp, data=dataallesclean, family = 'poisson')

model_list[[12]] = glm(larvaenormal ~ SUBleaves + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGImosses + WCalgae + ph + oxy + temp + depth, data=dataallesclean, family = 'poisson')

model_list[[13]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + WCmosses + oxy + temp + depth, data=dataallesclean, family = 'poisson') #SUBwood & Vegilowgrass weg

model_list[[14]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + WCmosses + oxy + temp, data=dataallesclean, family = 'poisson') #depth & SUBwood

model_list[[15]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + oxy + temp + depth, data=dataallesclean, family = 'poisson') #VEGilow & WCmoss

model_list[[16]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGItrees + WCmosses + oxy + temp + depth, data=dataallesclean, family = 'poisson') # VEgIhigh &vegilow

model_list[[17]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + WCmosses + temp + depth, data=dataallesclean, family = 'poisson') # oxy & SUbwood

model_list[[18]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBgrass + VEGItrees + VEGIhigh.grasses + WCmosses + oxy + depth, data=dataallesclean, family = 'poisson') #temp & Subalge & Vegilow

model_list[[19]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBalgae + VEGItrees + WCmosses + oxy + temp + depth, data=dataallesclean, family = 'poisson') #Subgrass & vegilow & vegihigh

model_list[[20]] = glm(larvaenormal ~ SUBmosses + SUBalgae + SUBgrass + VEGIhigh.grasses + VEGIlow.grasses + WCmosses + oxy + temp, data=dataallesclean, family = 'poisson') #vegitrees & subleaves & subwood & depth

model_list[[21]] = glm(larvaenormal ~ SUBleaves + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + oxy + temp + depth, data=dataallesclean, family = 'poisson') #wcmoss, submoss

model_list[[22]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + WCmosses + temp + depth, data=dataallesclean, family = 'poisson') #oxy &Vegilow

model_list[[23]] = glm(larvaenormal ~ SUBleaves + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + WCmosses + WCalgae + ph + oxy + temp + depth + con, data=dataallesclean, family = 'poisson') # Submoss Vegimoss

model_list[[24]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + VEGImosses + WCmosses + ph + oxy + temp + depth, data=dataallesclean, family = 'poisson') #con SUBalg & wcalg

model_list[[25]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGImosses + WCmosses + WCalgae + ph + oxy + temp + depth + con, data=dataallesclean, family = 'poisson') #Vegilow vegihigh subgrass

model_list[[26]] = glm(larvaenormal ~ SUBmosses + SUBwood + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + VEGImosses + WCmosses + WCalgae + oxy + temp + depth, data=dataallesclean, family = 'poisson') # SUbleaves ph con

model_list[[27]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBalgae + SUBgrass + VEGItrees + VEGIhigh.grasses + VEGIlow.grasses + VEGImosses + WCalgae + ph + oxy + temp + con, data=dataallesclean, family = 'poisson') #depth, wcmos, subwood

model_list[[28]] = glm(larvaenormal ~ SUBleaves + SUBmosses + SUBalgae + SUBgrass + VEGItrees + VEGImosses + WCmosses + WCalgae + ph + oxy + temp + depth, data=dataallesclean, family = 'poisson') # subwood, con, vegigraslow, vegihigh

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Appendix D: Master dataset

rv ae c atc h ( #) Ac id ity ( p H) O₂ -c o n ten t (mg /L) W ater temp ( ͦC ) Dep th ( cm) C o n ( u S/ cm) RD C o o rd in ates Ti me W ater p ro p er ti es CP OM FPO M leav es wo o d wat erpl an ts m o sses alg ae grass m o sses alg ae Co lo u r 1 4 .88 3 .55 1 0 .48 3 2 .50 1 0 9 .00 1 9 1 0 5 3 , 3 8 3 6 5 8 10:00 3 3 3 2 0 0 0 0 1 3 1 1 5 .30 2 .60 1 3 .60 2 5 .45 1 0 9 .00 1 9 1 0 5 3 , 3 8 3 6 5 8 14:00 3 3 3 2 0 0 0 0 1 0 1 105 5 .00 1 1 .13 1 4 .20 1 2 .67 1 1 4 .00 1 9 2 9 3 3 , 3 8 3 3 4 2 15:05 4 1 0 0 0 0 0 5 0 2 2 54 4 .50 6 .90 1 8 .30 1 1 .15 1 1 4 .00 1 9 2 9 0 7 , 3 8 3 3 4 9 11:00 4 1 1 0 0 2 0 2 2 1 2 0 6 .05 2 .40 1 5 .05 2 2 .08 1 0 8 .00 1 9 2 6 1 2 , 3 8 2 7 0 4 16:25 4 1 5 2 0 1 0 0 0 2 1 0 5 .30 2 .40 1 3 .40 1 6 .50 1 0 8 .00 1 9 2 6 1 2 , 3 8 2 7 0 4 13:00 4 1 5 2 0 1 0 0 0 2 1 7 5 .30 1 5 .20 1 1 .00 1 9 2 3 0 7 , 3 8 2 7 0 3 16:45 4 1 0 0 0 0 0 5 0 2 1 9 2 3 0 7 , 3 8 2 7 0 3 13:30 4 1 0 0 0 0 0 5 82 4 .53 5 .67 1 2 .07 9 .47 1 8 5 .00 1 9 2 1 0 0 , 3 8 1 6 5 6 11:01 4 1 3 1 0 0 0 3 1 2 2 6 3 .90 3 .60 1 3 .70 8 .00 1 8 5 .00 1 9 2 1 0 0 , 3 8 1 6 5 6 17:10 4 1 3 1 0 0 0 3 1 2 2 34 4 .40 1 0 .40 1 1 .80 2 2 .20 1 8 7 .00 1 9 1 9 3 7 , 3 8 1 8 9 0 13:12 1 4 2 1 0 0 0 1 5 3 2 0 3 .90 1 0 .40 1 4 .10 1 6 .50 1 8 7 .00 1 9 1 9 3 7 , 3 8 1 8 9 0 16:40 1 4 2 1 0 0 0 1 5 3 2 6 5 .10 3 .60 1 6 .10 1 1 .20 1 8 5 .00 1 9 2 1 9 7 , 3 8 1 9 9 8 13:50 4 1 4 1 0 0 0 1 3 1 3 4 3 .90 3 .60 1 3 .00 9 .00 1 8 5 .00 1 9 2 1 9 7 , 3 8 1 9 9 8 16:00 4 1 4 1 0 0 0 1 3 1 3 3 6 .10 6 .60 3 0 .00 1 8 8 6 3 7 , 3 8 3 4 6 9 9:52 3 3 4 1 0 1 0 0 1 1 1 4 .40 6 .20 6 .10 1 7 .55 1 8 8 6 1 0 , 3 8 3 5 0 0 10:46 5 0 1 0 0 0 0 5 1 5 39 4 .40 6 .20 1 4 .40 9 .50 1 8 8 6 1 0 , 3 8 3 5 0 0 10:40 5 0 1 0 0 0 0 5 1 1 6 3 .90 7 .80 2 1 .60 1 8 8 8 9 0 , 3 8 3 6 4 3 11:25 3 3 3 1 0 0 0 3 2 1 0 1 8 8 8 9 0 , 3 8 3 6 4 3 11:30 3 3 3 1 0 0 0 3 2 1 0 4 .80 1 7 .00 3 3 .50 1 8 8 9 0 4 , 3 8 3 5 4 9 14:00 4 1 0 0 0 2 0 4 5 0 0 4 .80 1 7 .00 8 .50 1 8 8 9 0 4 , 3 8 3 5 4 9 11:50 4 1 0 0 0 2 0 4 4 0 0 4 .06 7 .00 1 3 .80 9 .55 1 9 4 .00 1 9 0 7 7 9 , 3 8 2 5 0 8 13:58 4 1 0 0 0 0 1 5 2 1 1 2 3 .80 9 .90 1 5 .80 9 .00 1 9 4 .00 1 9 0 7 7 9 , 3 8 2 5 0 8 16:30 4 1 0 0 0 0 0 5 2 1 1 11 4 .35 8 .80 1 7 .05 2 6 .11 1 0 9 .00 1 9 1 0 2 0 , 3 8 2 6 6 1 14:35 1 4 4 2 0 0 0 0 0 0 2 0 5 .30 3 .10 1 3 .60 1 2 .50 1 0 9 .00 1 9 1 0 2 0 , 3 8 2 6 6 1 13:45 1 4 4 2 0 0 0 0 0 0 2 18 4 .00 5 .70 1 4 .90 1 3 .64 1 7 0 .00 1 9 0 2 7 3 , 3 8 2 9 0 4 15:45 3 3 4 1 0 2 0 0 5 1 1 0 4 .20 3 .50 1 3 .00 1 9 .00 1 7 0 .00 1 9 0 2 7 3 , 3 8 2 9 0 4 14:15 3 3 4 1 0 2 0 0 5 1 1 6 4 .10 9 .70 1 6 .00 1 5 .63 1 9 0 7 6 5 , 3 8 3 1 7 5 16:48 3 3 2 1 0 0 0 3 3 0 2 1 9 0 7 6 5 , 3 8 3 1 7 5 14:30 3 0 2 0 4 .00 3 .20 1 0 .30 1 4 .50 1 9 0 5 7 5 , 3 8 2 2 5 8 11:00 4 1 4 1 0 0 0 2 1 1 1 9 0 5 7 5 , 3 8 2 2 5 8 13:45 0 0 0 3 .70 7 .30 1 0 .30 1 0 .00 1 9 0 5 1 4 , 3 8 2 1 8 0 11:30 4 1 0 0 0 0 1 5 0 1 1 9 0 5 1 4 , 3 8 2 1 8 0 15:15 0 4 .40 4 .70 1 4 .60 1 0 .45 1 9 0 4 0 5 , 3 8 2 1 7 4 12:37 4 2 5 1 0 0 0 0 0 0 1 9 0 4 0 5 , 3 8 2 1 7 4 13:30 6 1 0 .00 1 9 0 2 4 9 , 3 8 2 0 6 5 13:35 4 2 4 1 0 0 0 3 0 0 1 9 0 2 4 9 , 3 8 2 0 6 5 13:35 8 3 .90 1 1 .60 1 4 .60 1 5 .91 1 8 7 .00 1 9 0 4 3 4 , 3 8 1 9 1 6 16:46 4 1 1 1 0 1 0 0 2 1 3 0 3 .90 1 0 .00 1 2 .20 8 .75 1 8 7 .00 1 9 0 4 3 4 , 3 8 1 9 1 6 13:15 3 3 3 1 0 0 0 0 2 2 3 0 5 .90 1 .40 1 3 .40 2 8 .00 7 5 .00 1 8 9 8 2 6 , 3 8 2 8 8 8 11:00 3 3 4 1 0 0 0 1 1 1 3 0 6 .40 4 2 .22 1 9 2 5 9 7 , 3 8 3 6 4 7 13:00 4 1 4 1 0 0 0 0 0 1 0 6 .40 4 2 .22 1 9 2 5 9 7 , 3 8 3 6 4 7 14:30 4 1 4 1 0 0 0 0 0 1 0 6 .40 3 6 .11 1 9 0 8 9 1 , 3 8 3 8 2 6 13:50 4 1 4 1 0 0 0 0 0 1 0 6 .40 3 6 .11 1 9 0 8 9 1 , 3 8 3 8 2 6 14:45 4 1 4 1 0 0 0 0 0 1 48 3 .90 4 .60 2 1 .00 2 3 .85 1 8 7 .00 1 9 1 2 7 1 , 3 8 3 5 8 9 13:00 4 1 1 0 0 0 1 5 1 1 1 3 3 .90 4 .60 1 4 .00 1 4 .50 1 8 7 .00 1 9 1 2 7 1 , 3 8 3 5 8 9 15:00 4 1 1 0 0 0 1 5 1 1 1 131 4 .30 6 .50 2 0 .60 1 1 .50 1 2 5 .50 1 9 1 3 1 8 , 3 8 3 5 4 0 14:00 3 2 4 1 0 0 1 1 2 2 1 11 4 .00 6 .50 1 3 .70 1 0 .50 1 8 2 .00 1 9 1 3 1 8 , 3 8 3 5 4 0 15:30 3 2 4 1 0 0 1 1 2 2 1 0 5 .40 4 .90 2 0 .30 2 1 .50 1 0 4 .60 1 9 1 2 7 9 , 3 8 3 5 1 2 15:00 3 3 4 1 0 0 0 1 0 0 3 0 5 .20 4 .90 1 3 .40 2 1 .50 1 1 5 .00 1 9 1 2 7 9 , 3 8 3 5 1 2 15:45 3 3 4 1 0 0 0 1 0 0 3 0 5 .50 1 9 .40 1 5 .91 1 5 7 .00 1 9 1 2 2 1 , 3 8 3 5 2 8 15:30 4 1 5 2 0 0 0 0 0 1 1 9 1 2 2 1 , 3 8 3 5 2 8 15:30 0 0 1 4 .10 2 .90 2 2 .00 1 3 .50 9 2 .00 1 9 1 2 6 6 , 3 8 3 4 3 0 16:00 4 1 0 0 0 0 0 5 0 0 2 8 3 .80 2 .90 1 2 .40 1 1 .50 1 9 2 .00 1 9 1 2 6 6 , 3 8 3 4 3 0 16:00 4 1 0 0 0 0 0 5 0 0 2 40 3 .60 1 8 .90 1 5 .00 5 4 .00 1 9 1 2 7 0 , 3 8 3 3 2 2 17:00 4 1 3 1 0 0 2 3 2 3 2 0 3 .90 2 .70 1 2 .70 1 2 .86 1 8 8 .00 1 9 1 2 7 0 , 3 8 3 3 2 2 16:45 4 1 3 1 0 0 2 3 2 3 2 54 4 .10 4 .00 1 7 .40 1 1 .00 1 7 2 .00 1 9 1 7 4 5 , 3 8 3 2 6 6 11:00 3 2 1 0 0 0 0 3 0 4 1 0 4 .30 4 .50 1 1 .00 1 0 .50 1 6 5 .00 1 9 1 7 4 5 , 3 8 3 2 6 6 17:45 3 2 3 1 0 0 0 3 0 4 1 1 4 .00 5 .70 1 7 .40 4 5 .00 1 8 6 .00 1 9 1 7 0 6 , 3 8 3 2 6 8 12:00 4 1 2 0 0 0 0 2 0 5 2 6 4 .30 5 .70 1 2 .40 3 8 .00 1 6 5 .00 1 9 1 6 5 6 , 3 8 3 2 7 8 17:00 4 1 2 0 0 0 0 2 1 5 1 5 4 .40 6 .70 1 6 .90 1 6 .50 1 6 4 .00 1 9 1 7 4 0 , 3 8 3 3 2 6 12:15 4 1 0 0 0 0 0 4 0 4 1 0 4 .00 3 .20 1 3 .10 1 3 .50 1 8 1 .00 1 9 1 7 4 0 , 3 8 3 3 2 6 17:15 4 1 0 0 0 0 0 4 1 4 1 6 4 .50 9 .80 1 8 .60 1 6 .36 1 5 3 .00 1 9 1 8 8 4 , 3 8 3 1 7 1 13:30 4 1 0 0 0 0 0 5 0 4 1 0 4 .30 1 3 .00 1 9 .20 8 .00 1 2 6 .00 1 9 1 3 3 2 , 3 8 3 0 3 7 14:30 4 1 5 0 0 0 0 0 0 4 2 0 4 .40 3 .10 1 2 .40 9 .00 1 6 1 .00 1 9 1 3 3 2 , 3 8 3 0 3 7 18:30 4 1 5 2 0 0 0 0 1 0 2 9 4 .30 9 .38 1 6 4 .00 1 9 1 3 6 4 , 3 8 3 0 0 9 14:50 3 2 2 0 0 0 0 2 0 4 3 1 9 1 3 6 4 , 3 8 3 0 0 9 14:50 46 3 .60 7 .50 1 9 .10 7 .86 2 0 4 .00 1 9 0 2 8 8 , 3 8 2 1 6 5 16:20 3 2 2 0 0 1 2 2 0 4 3 1 9 0 2 8 8 , 3 8 2 1 6 5 13:00 0 4 33 3 .30 3 .00 1 7 .40 8 .33 2 2 4 .00 1 9 0 4 6 0 , 3 8 3 3 7 9 11:00 5 0 4 0 0 3 0 2 0 3 3 1 9 0 4 6 0 , 3 8 3 3 7 9 11:00 0 3 .60 2 .00 1 7 .90 1 5 .63 2 1 1 .00 1 9 0 6 2 7 , 3 8 3 4 9 1 11:55 4 1 1 0 0 4 0 0 0 1 2 1 9 0 6 2 7 , 3 8 3 4 9 1 11:30 26 3 .50 8 .80 1 8 .00 1 5 .50 2 0 6 .00 1 9 0 6 2 3 , 3 8 3 4 9 2 12:15 4 1 0 0 0 0 0 5 0 2 1 16 3 .60 2 .00 1 7 .90 1 0 .00 2 1 1 .00 1 9 0 6 2 3 , 3 8 3 4 9 2 11:45 3 3 1 0 0 0 0 5 4 1 1 33 3 .70 6 .80 2 1 .20 1 2 .73 2 0 2 .00 1 9 0 5 5 7 , 3 8 3 5 4 0 13:30 5 0 4 0 0 0 0 1 0 3 3 2 3 .70 4 .40 1 5 .60 9 .50 2 0 2 .00 1 9 0 5 5 7 , 3 8 3 5 4 0 12:30 5 0 4 0 0 0 0 1 5 1 3 98 4 .00 7 .10 2 3 .10 1 9 .50 1 8 0 .00 1 9 0 5 1 2 , 3 8 3 5 0 4 14:30 5 0 1 0 0 0 0 4 0 1 2 23 3 .80 1 0 .50 1 8 .30 1 2 .50 1 9 7 .00 1 9 0 0 0 3 , 3 8 3 0 9 1 16:00 1 4 4 0 0 0 0 1 0 5 2 0 3 .80 3 .00 1 5 .60 1 1 .50 1 9 7 .00 1 9 0 0 0 3 , 3 8 3 0 9 1 14:00 1 4 4 0 0 0 0 1 0 2 2 10 4 .00 3 .20 1 7 .80 1 0 .00 1 8 7 .00 1900145, 383074 16:30 4 1 5 0 0 0 0 0 0 0 2 1900145, 383074 13:30 4 1 5 0 0 0 0 0 2 0 4 .40 0 .80 1 7 .40 1 9 .17 1 4 5 .00 1 9 2 2 7 8 , 3 8 2 9 6 0 12:00 3 2 5 0 0 0 0 0 0 5 2 0 4 .40 1 .60 1 3 .60 1 2 .50 1 4 5 .00 1 9 2 2 7 8 , 3 8 2 9 6 0 13:20 3 2 5 1 0 0 0 0 1 2 3 2 3 .60 8 .20 1 7 .00 1 3 .89 9 9 .50 1 9 2 2 9 1 , 3 8 2 9 7 1 12:30 5 0 0 0 0 0 0 5 0 3 2 8 5 .90 8 .20 1 7 .00 8 .00 7 1 .00 1 9 2 2 9 1 , 3 8 2 9 7 1 13:40 5 0 0 0 0 0 0 5 1 4 2 4 3 .50 2 .00 1 6 .50 2 1 .00 1 0 7 .00 1 9 2 1 7 3 , 3 8 2 7 3 4 12:50 3 2 5 0 0 0 0 0 0 1 3 0 3 .80 1 .00 1 2 .20 1 5 .00 1 9 5 .00 1 9 2 1 7 3 , 3 8 2 7 3 4 14:15 3 2 5 0 0 0 0 0 0 1 2 23 3 .90 1 0 .30 1 8 .70 1 1 .67 1 0 4 .00 1 9 1 9 6 5 , 3 8 2 9 8 3 14:15 4 1 1 0 0 0 0 4 0 3 2 0 3 .60 5 .70 1 4 .20 1 0 .00 2 0 6 .00 1 9 1 9 6 5 , 3 8 2 9 8 3 14:40 5 1 3 1 0 0 0 3 1 4 2 26 4 .00 1 .80 1 8 .60 9 .00 7 8 .00 1 9 1 6 4 4 , 3 8 2 5 9 7 15:40 4 1 5 0 0 0 0 1 0 3 2 1 4 .00 4 .90 1 2 .80 1 3 .00 7 8 .00 1 9 1 6 4 4 , 3 8 2 5 9 7 18:00 4 1 5 0 0 0 0 1 4 1 3 0 6 .60 1 .60 1 6 .70 1 2 .73 1 8 9 6 8 1 , 3 8 3 1 4 5 10:45 2 3 5 0 0 0 0 0 0 0 1 5 3 .78 3 .60 1 9 .40 1 3 .33 1 3 5 .00 1 8 9 7 9 9 , 3 8 2 3 5 5 11:20 2 3 3 0 0 2 0 2 0 2 2 0 4 .63 2 .50 1 9 .00 2 1 .67 1 7 7 .00 1 8 9 9 3 7 , 3 8 2 3 3 9 12:30 5 0 0 0 0 0 0 5 0 3 3 0 3 .90 1 0 .00 1 2 .20 2 2 .00 1 8 7 .00 1 8 9 9 1 9 , 3 8 2 3 3 5 2371903 0:00:00 4 1 0 0 0 0 1 4 1 5 3 0 7 .20 7 .10 1 6 .80 1 7 .50 1 8 9 9 8 8 , 3 8 2 1 1 9 11:30 1 4 1 0 0 0 1 1 0 3 1 0 4 .50 2 .70 1 3 .70 1 8 .00 1 5 0 .00 1 9 0 9 3 4 , 3 8 2 8 3 3 12:30 2 3 4 0 0 1 0 1 2 3 3 11 5 .80 7 .90 1 2 .30 1 1 .00 7 6 .00 1 9 0 6 2 7 , 3 8 2 9 1 8 13:00 1 4 1 0 0 0 0 4 1 5 2 0 5 .20 4 .10 1 4 .70 1 3 .64 1 1 1 .00 1 9 0 7 5 0 , 3 8 2 9 6 6 14:00 4 1 3 0 0 0 0 3 1 5 2 0 6 .00 4 .70 1 5 .40 8 .89 7 1 .00 1 8 9 8 5 2 , 3 8 2 7 9 1 15:00 3 3 0 0 0 0 0 5 1 0 1 8 3 .90 6 .40 1 3 .50 1 1 .50 1 8 7 .00 1 9 2 0 8 2 , 3 8 2 5 7 9 15:15 4 1 3 2 0 0 1 3 1 2 3 4 4 .20 3 .30 1 3 .10 1 5 .50 1 6 8 .00 1 9 0 9 4 2 , 3 8 2 8 7 2 15:10 5 1 5 1 0 0 0 0 0 0 2 1 5 .40 3 .80 1 5 .50 1 3 .00 1 0 6 .00 1 9 1 0 0 6 , 3 8 2 7 1 6 15:30 1 4 0 0 0 1 0 5 1 1 2 Su b str ate: ( sc al e 1 -5) W ater co ve r: ( sc al e 1 -5)

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Ac id ity ( p H) O ₂-co n ten t (mg /L ) W ater temp ( ͦC ) Dep th ( cm) C o n ( u S/ cm) RD C o o rd in ates Ti me W ater p ro p er ti es CP OM FPO M leav es wo o d wat erpl an ts m o sses alg ae grass m o sses alg ae Co lo u r 0 4 .30 1 3 .00 1 9 .20 8 .00 1 2 6 .00 1 9 1 3 3 2 , 3 8 3 0 3 7 14:30 4 1 5 0 0 0 0 0 0 4 2 0 4 .40 3 .10 1 2 .40 9 .00 1 6 1 .00 1 9 1 3 3 2 , 3 8 3 0 3 7 18:30 4 1 5 2 0 0 0 0 1 0 2 9 4 .30 9 .38 1 6 4 .00 1 9 1 3 6 4 , 3 8 3 0 0 9 14:50 3 2 2 0 0 0 0 2 0 4 3 1 9 1 3 6 4 , 3 8 3 0 0 9 14:50 46 3 .60 7 .50 1 9 .10 7 .86 2 0 4 .00 1 9 0 2 8 8 , 3 8 2 1 6 5 16:20 3 2 2 0 0 1 2 2 0 4 3 1 9 0 2 8 8 , 3 8 2 1 6 5 13:00 0 4 33 3 .30 3 .00 1 7 .40 8 .33 2 2 4 .00 1 9 0 4 6 0 , 3 8 3 3 7 9 11:00 5 0 4 0 0 3 0 2 0 3 3 1 9 0 4 6 0 , 3 8 3 3 7 9 11:00 0 3 .60 2 .00 1 7 .90 1 5 .63 2 1 1 .00 1 9 0 6 2 7 , 3 8 3 4 9 1 11:55 4 1 1 0 0 4 0 0 0 1 2 1 9 0 6 2 7 , 3 8 3 4 9 1 11:30 26 3 .50 8 .80 1 8 .00 1 5 .50 2 0 6 .00 1 9 0 6 2 3 , 3 8 3 4 9 2 12:15 4 1 0 0 0 0 0 5 0 2 1 16 3 .60 2 .00 1 7 .90 1 0 .00 2 1 1 .00 1 9 0 6 2 3 , 3 8 3 4 9 2 11:45 3 3 1 0 0 0 0 5 4 1 1 33 3 .70 6 .80 2 1 .20 1 2 .73 2 0 2 .00 1 9 0 5 5 7 , 3 8 3 5 4 0 13:30 5 0 4 0 0 0 0 1 0 3 3 2 3 .70 4 .40 1 5 .60 9 .50 2 0 2 .00 1 9 0 5 5 7 , 3 8 3 5 4 0 12:30 5 0 4 0 0 0 0 1 5 1 3 98 4 .00 7 .10 2 3 .10 1 9 .50 1 8 0 .00 1 9 0 5 1 2 , 3 8 3 5 0 4 14:30 5 0 1 0 0 0 0 4 0 1 2 23 3 .80 1 0 .50 1 8 .30 1 2 .50 1 9 7 .00 1 9 0 0 0 3 , 3 8 3 0 9 1 16:00 1 4 4 0 0 0 0 1 0 5 2 0 3 .80 3 .00 1 5 .60 1 1 .50 1 9 7 .00 1 9 0 0 0 3 , 3 8 3 0 9 1 14:00 1 4 4 0 0 0 0 1 0 2 2 10 4 .00 3 .20 1 7 .80 1 0 .00 1 8 7 .00 1900145, 383074 16:30 4 1 5 0 0 0 0 0 0 0 2 1900145, 383074 13:30 4 1 5 0 0 0 0 0 2 0 4 .40 0 .80 1 7 .40 1 9 .17 1 4 5 .00 1 9 2 2 7 8 , 3 8 2 9 6 0 12:00 3 2 5 0 0 0 0 0 0 5 2 0 4 .40 1 .60 1 3 .60 1 2 .50 1 4 5 .00 1 9 2 2 7 8 , 3 8 2 9 6 0 13:20 3 2 5 1 0 0 0 0 1 2 3 2 3 .60 8 .20 1 7 .00 1 3 .89 9 9 .50 1 9 2 2 9 1 , 3 8 2 9 7 1 12:30 5 0 0 0 0 0 0 5 0 3 2 8 5 .90 8 .20 1 7 .00 8 .00 7 1 .00 1 9 2 2 9 1 , 3 8 2 9 7 1 13:40 5 0 0 0 0 0 0 5 1 4 2 4 3 .50 2 .00 1 6 .50 2 1 .00 1 0 7 .00 1 9 2 1 7 3 , 3 8 2 7 3 4 12:50 3 2 5 0 0 0 0 0 0 1 3 0 3 .80 1 .00 1 2 .20 1 5 .00 1 9 5 .00 1 9 2 1 7 3 , 3 8 2 7 3 4 14:15 3 2 5 0 0 0 0 0 0 1 2 23 3 .90 1 0 .30 1 8 .70 1 1 .67 1 0 4 .00 1 9 1 9 6 5 , 3 8 2 9 8 3 14:15 4 1 1 0 0 0 0 4 0 3 2 0 3 .60 5 .70 1 4 .20 1 0 .00 2 0 6 .00 1 9 1 9 6 5 , 3 8 2 9 8 3 14:40 5 1 3 1 0 0 0 3 1 4 2 26 4 .00 1 .80 1 8 .60 9 .00 7 8 .00 1 9 1 6 4 4 , 3 8 2 5 9 7 15:40 4 1 5 0 0 0 0 1 0 3 2 1 4 .00 4 .90 1 2 .80 1 3 .00 7 8 .00 1 9 1 6 4 4 , 3 8 2 5 9 7 18:00 4 1 5 0 0 0 0 1 4 1 3 0 6 .60 1 .60 1 6 .70 1 2 .73 1 8 9 6 8 1 , 3 8 3 1 4 5 10:45 2 3 5 0 0 0 0 0 0 0 1 5 3 .78 3 .60 1 9 .40 1 3 .33 1 3 5 .00 1 8 9 7 9 9 , 3 8 2 3 5 5 11:20 2 3 3 0 0 2 0 2 0 2 2 0 4 .63 2 .50 1 9 .00 2 1 .67 1 7 7 .00 1 8 9 9 3 7 , 3 8 2 3 3 9 12:30 5 0 0 0 0 0 0 5 0 3 3 0 3 .90 1 0 .00 1 2 .20 2 2 .00 1 8 7 .00 1 8 9 9 1 9 , 3 8 2 3 3 5 2371903 0:00:00 4 1 0 0 0 0 1 4 1 5 3 0 7 .20 7 .10 1 6 .80 1 7 .50 1 8 9 9 8 8 , 3 8 2 1 1 9 11:30 1 4 1 0 0 0 1 1 0 3 1 0 4 .50 2 .70 1 3 .70 1 8 .00 1 5 0 .00 1 9 0 9 3 4 , 3 8 2 8 3 3 12:30 2 3 4 0 0 1 0 1 2 3 3 11 5 .80 7 .90 1 2 .30 1 1 .00 7 6 .00 1 9 0 6 2 7 , 3 8 2 9 1 8 13:00 1 4 1 0 0 0 0 4 1 5 2 0 5 .20 4 .10 1 4 .70 1 3 .64 1 1 1 .00 1 9 0 7 5 0 , 3 8 2 9 6 6 14:00 4 1 3 0 0 0 0 3 1 5 2 0 6 .00 4 .70 1 5 .40 8 .89 7 1 .00 1 8 9 8 5 2 , 3 8 2 7 9 1 15:00 3 3 0 0 0 0 0 5 1 0 1 8 3 .90 6 .40 1 3 .50 1 1 .50 1 8 7 .00 1 9 2 0 8 2 , 3 8 2 5 7 9 15:15 4 1 3 2 0 0 1 3 1 2 3 4 4 .20 3 .30 1 3 .10 1 5 .50 1 6 8 .00 1 9 0 9 4 2 , 3 8 2 8 7 2 15:10 5 1 5 1 0 0 0 0 0 0 2 1 5 .40 3 .80 1 5 .50 1 3 .00 1 0 6 .00 1 9 1 0 0 6 , 3 8 2 7 1 6 15:30 1 4 0 0 0 1 0 5 1 1 2 Su b str ate: ( sc al e 1 -5) W ater co ve r: ( sc al e 1 -5)

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Appendix E: Detailed raw data per sample location

Location: 1 Datum: 20-4-2016

# Larvae catch (#) Acidity (pH) O₂-content (mg/L) Water temp ( ͦC) Depth (cm) Con (uS/cm)

1.0.01 4 4.9 2.8 10.2 30 109 1.0.02 6 40 1.0.03 2 20 1.0.04 0 30 1.0.05 0 35 1.0.06 1 4.9 3.7 9.7 35 1.0.07 1 30 1.0.08 0 45 1.0.09 0 40 1.0.10 1 40 1.0.11 0 60 1.0.12 1 4.4 4.5 10.2 40 1.0.13 0 20 1.0.14 1 5 1.0.15 0 30 1.0.16 0 15 1.0.17 0 15 1.0.18 0 25 1.0.19 2 45 1.0.20 1 5.3 3.2 11.8 50 average 1 4.875 3.55 10.475 32.5 GPS: 191053, 383658 tot 191268, 383638 Time: 10:00 Substrate: leaves (%) 3 wood (%) 2 CPOM (%) 3 FPOM (%) 3 waterplants (%) 0 mosses (%) 0 algae (%) 0 grass (%) 0 Vegetation: trees (%) 4 trees (height m) 0 bush (%) 0 bush (height m) 0 heath (%) 0 heather (height cm) 0 high grasses (%) 1

high grasses (height cm) 0

low grasses (%) 3

low grasses (height cm) 0

mosses (%) 0 Water cover: mosses (%) 1 algae (%) 3 Weather: sunshine 1 partial overcast 1 overcast 0 no wind 0 little wind 1 wind 0 rain 0 Dimensions: width (m) 2 length (m) 225 avarege depth (cm) 32.5 water cover (%) 100

estimated total volume (m3) 146.25

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Location: 1-1 Datum: 23-5-2016

# Larvae catch (#) Acidity (pH) O₂-content (mg/L) Water temp ( ͦC) Depth (cm) Con (uS/cm)

1.1.01 1 5.3 2.6 13.6 20 109 1.1.02 0 20 1.1.03 0 35 1.1.04 0 30 1.1.05 0 15 1.1.06 0 25 1.1.07 1 25 1.1.08 0 15 1.1.09 0 35 1.1.10 0 20 1.1.11 0 40 average 0.18 25.45 GPS: 191053, 383658 Time: 14:00 Substrate: leaves (%) 3 wood (%) 2 CPOM (%) 3 FPOM (%) 3 waterplants (%) 0 mosses (%) 0 algae (%) 0 grass (%) 0 Vegetation: trees (%) 5 trees (height m) 0 bush (%) 0 bush (height m) 0 heath (%) 0 heather (height cm) 0 high grasses (%) 2

high grasses (height cm) 0

low grasses (%) 3

low grasses (height cm) 0

mosses (%) 0 Water cover: mosses (%) 1 algae (%) 0 Weather: sunshine 0 partial overcast 0 overcast 1 no wind 0 little wind 1 wind 0 rain 1 Dimensions: width (m) 2 length (m) 225 avarege depth (cm) 25.45 water cover (%) 90

estimated total volume (m3) 103.07

Water Properties:

Colour 1

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Location: 4 Datum: 20-4-2016

# Larvae catch (#) Acidity (pH) O₂-content (mg/L) Water temp ( ͦC) Depth (cm) Con (uS/cm)

4.0.01 0 5 11.4 13.9 10 114 4.0.02 1 10 4.0.03 4 10 4.0.04 4 15 4.0.05 3 15 4.0.06 1 15 4.0.07 6 10 4.0.08 9 10 4.0.09 11 20 4.0.10 >20 4.4 14 14.7 15 4.0.11 7 15 4.0.12 9 10 4.0.13 16 15 4.0.14 9 5 4.0.15 5 5.6 8 14 15 average 6.071428571 12.67 GPS: 192933, 383342 Time: 15:05 Substrate: leaves (%) 0 wood (%) 0 CPOM (%) 4 FPOM (%) 1 waterplants (%) 0 mosses (%) 0 algae (%) 0 grass (%) 5 Vegetation: trees (%) 1 trees (height m) bush (%) 0 bush (height m) heath (%) 0 heather (height cm) high grasses (%) 4

high grasses (height cm)

low grasses (%) 0

low grasses (height cm)

mosses (%) 1 Water cover: mosses (%) 0 algae (%) 2 Weather: sunshine 1 partial overcast 0 overcast 0 no wind 1 little wind 0 wind 0 rain 0 Dimensions: width (m) 50 length (m) 50 avarege depth (cm) 12.7 water cover (%) 30

estimated total volume (m3) 95.03

Water Properties:

Colour 2

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Location: 4-1 Datum: 12-5-2016

# Larvae catch (#) Acidity (pH) O₂-content (mg/L) Water temp ( ͦC) Depth (cm) Con (uS/cm)

4.1.01 0 4.5 6.9 18.3 15 114 4.1.02 0 15 4.1.03 0 15 4.1.04 5 10 4.1.05 2 10 4.1.06 1 15 4.1.07 12 5 4.1.08 2 10 4.1.09 12 10 4.1.10 1 10 4.1.11 7 5 4.1.12 9 10 4.1.13 9 15 average 4.62 11.15 GPS: 192907, 383349 Time: 11:00 Substrate: leaves (%) 1 wood (%) 0 CPOM (%) 4 FPOM (%) 1 waterplants (%) 0 mosses (%) 2 algae (%) 0 grass (%) 2 Vegetation: trees (%) 2 berken trees (height m) bush (%) 0 bush (height m) 0 heath (%) 0 heather (height cm)

high grasses (%) 4 pijpenstrootje

high grasses (height cm)

low grasses (%) 0

low grasses (height cm)

mosses (%) 2 veenmos Water cover: mosses (%) 2 algae (%) 1 Weather: sunshine 1 partial overcast 0 overcast 0 no wind 1 little wind 0 wind 0 rain 0 Dimensions: width (m) 50 length (m) 50 avarege depth (cm) 11.15 water cover (%) 20

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Location: 5 Datum: 20-4-2016

# Larvae catch (#) Acidity (pH) O₂-content (mg/L) Water temp ( ͦC) Depth (cm) Con (uS/cm)

L 5.0.01 0 6.6 13.8 10 108 R 5.0.02 0 5.5 16.3 15 R 5.0.03 0 30 L 5.0.04 0 25 R 5.0.05 0 25 R 5.0.06 0 25 L 5.0.07 0 30 L 5.0.08 0 40 R 5.0.09 0 40 L 5.0.10 1 10 R 5.0.11 0 10 L 5.0.12 2 5 average 0.25 6.05 15.05 22.08 GPS: 192612, 382704 Time: 16:25 Substrate: leaves (%) 5 wood (%) 2 CPOM (%) 4

FPOM (%) 1 NO IMAGE AVAILABLE

waterplants (%) 0 mosses (%) 1 algae (%) 0 grass (%) 0 Vegetation: trees (%) 1 trees (height m) bush (%) 5 bush (height m) heath (%) 0 heather (height cm) high grasses (%) 1

high grasses (height cm)

low grasses (%) 1

low grasses (height cm)

mosses (%) 1 Water cover: mosses (%) 0 algae (%) 2 Weather: sunshine 1 partial overcast 0 overcast 0 no wind 0 little wind 1 wind 0 rain 0 Dimensions: width 600 length 100 avarege depth 22.08 water cover (%) 100

estimated total volume (m3) 13250.00 Water Properties:

Colour 1

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Location: 5-1 Datum: 24-5-2016

# Larvae catch (#) Acidity (pH) O₂-content (mg/L) Water temp ( ͦC) Depth (cm) Con (uS/cm)

5.1.01 0 5.3 2.4 13.4 15 108 5.1.02 0 5 5.1.03 0 15 5.1.04 0 20 5.1.05 0 10 5.1.06 0 15 5.1.07 0 5 5.1.08 0 30 5.1.09 0 25 5.1.10 0 25 average 0 16.5 GPS: 192612, 382704 Time: 13:00 Substrate: leaves (%) 5 wood (%) 2 CPOM (%) 4 FPOM (%) 1 waterplants (%) 0 mosses (%) 1 algae (%) 0 grass (%) 0 Vegetation: trees (%) 1 trees (height m) bush (%) 5 bush (height m) heath (%) 0 heather (height cm) high grasses (%) 1

high grasses (height cm)

low grasses (%) 1

low grasses (height cm)

mosses (%) 1 Water cover: mosses (%) 0 algae (%) 2 Weather: sunshine 0 partial overcast 0 overcast 1 no wind 0 little wind 0 wind 1 rain 0 Dimensions: width (m) 600 length (m) 100 avarege depth (cm) 16.5 water cover (%) 100

estimated total volume (m3) 9900 Water Properties:

Colour 1

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Location: 6 Datum: 20-4-2016

# Larvae catch (#) Acidity (pH) O₂-content (mg/L) Water temp ( ͦC) Depth (cm) Con (uS/cm)

6.0.01 2 5.3 15.2 7 6.0.02 1 10 6.0.03 2 10 6.0.04 3 15 6.0.05 6 15 6.0.06 8 10 6.0.07 8 10 average 4.29 11 GPS: 192307, 382703 Time: 16:45 Substrate: leaves (%) 0 wood (%) 0 CPOM (%) 4 FPOM (%) 1 waterplants (%) 0 mosses (%) 0 algae (%) 0 grass (%) 5 Vegetation: trees (%) 2 trees (height m) bush (%) 0 bush (height m) heath (%) 0 heather (height cm) high grasses (%) 5

high grasses (height cm)

low grasses (%) 0

low grasses (height cm)

mosses (%) 1 Water cover: mosses (%) 0 algae (%) 2 Weather: sunshine 1 partial overcast 0 overcast 0 no wind 1 little wind 0 wind 0 rain 0 Dimensions: width (m) 60 length (m) 100 avarege depth (cm) 11.0 water cover (%) 5

estimated total volume (m3) 33.00 Water Properties:

Colour Turbidity (mm)

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