Future prospects for the Cumbrian lakes:

Applications of the PROTECH lake model

Dr Alex Elliott

CEH

Contact: alexe@ceh.ac.uk

Future threats

• Nutrient enrichment

• Climate change

• Species invasion/loss

• All inter-linked

PROTECH

(Phytoplankton RespOnses To Environmental CHange)

0

2

4

6

8

10

12

14

1 51 101 151 201 251 301 351

Day of year

Ch

loro

ph

yll a

(m

g m

-3)

• PROTECH predicts the biomass and species

composition of the algal community giving it a unique

world status

PROTECH

Future threats: Nutrient enrichment

Windermere

0

5

10

15

20

25

0 100 200 300

Baseline

245 scenario

430 scenario

Day of Year

• Testing future strategies for

United Utilities

• Sewage treatment work

improvements

North basin South basin

Future threats: Climate change

Temperature difference (°C

)

Proportional change

in nutrient load

Maxim

um

perc

en

tag

e

cyan

ob

acte

rial ab

un

dan

ce

30

40

50

• Changes in maximum

abundance of

cyanobacteria

Present day

Future threats: Species loss

• Vendace (Coregonus albula)

• Maximum length 250 mm

• Low temperatures (<15°C)

• High oxygen levels (>5 mg L-1)

• To predict how vendace habitat volume will be affected

in Bassenthwaite Lake under predicted future climate

change

Bassenthwaite Lake

• Max Depth = 19.0 m

• Mean Depth = 5.3 m

• Length = 6.2 km

• Volume = 27.9 x 106 m3

• Area = 5.28 km2

Future threats: Species loss

Future threats: Species loss

>18.5 oC

Habitat volume

• Volume of water that does NOT exceed critical

temperature and oxygen limits

Summer

Vendace habitat volume

Future threats: Species loss

>18.5 oC

Habitat volume

• Volume of water that does NOT exceed critical

temperature and oxygen limits

Late Summer

Vendace habitat volume

O2<2 mg L-1

Future threats: Species lossThe method

PROTECH

Cloud

Weather scenarios

Regional

Climate

Model

Wind Air

temperature

PresentFuture

(2070-90)

20 years of algal and temperature

output for both present and future

Weather scenarios (UK Met Office)

LOX

Habitat

volume

Future threats: Species loss

Comparison between present and future

Surface water temperature

0

5

10

15

20

25

1 2 3 4 5 6 7 8 9 10 11 12

Month of year

Wa

ter

tem

pe

ratu

re (

oC

)

Future mean

Present mean

Future threats: Species loss

Comparison between present and future

Deep water temperature

0

5

10

15

20

25

1 2 3 4 5 6 7 8 9 10 11 12

Month of year

Wa

ter

tem

pe

ratu

re (

oC

)

Future Mean

Present Mean

Future threats: Species lossThe future for Bassenthwaite Lake

• Temperature had the biggest effect

• Every year in the future has days of 0 habitat volume

Number of consecutive days with zero modelled habitat

0

10

20

30

40

50

60

70

80

90

100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Nom inal year

Nu

mb

er

of

co

nse

cu

tive d

ays

present day

future

7 day threshold

Habitat volume

Conclusions

• Predicting the impact of the future requires knowledge

of the present

• CEH’s PROTECH model provides a method for

utilising that knowledge

• PROTECH provides a tried and test way of quantifying

those future changes and the impact of management

strategies

0

2

4

6

8

10

12

14

1 51 101 151 201 251 301 351

Day of year

Ch

loro

ph

yll a

(m

g m

-3)