IUKWC Workshop Freshwater EO About Loch Leven Laurence Carvalho

1. Loch Leven
Laurence Carvalho
Centre for Ecology & Hydrology (Edinburgh)
laca@ceh.ac.uk

2. • CEH Lake observatories
• Loch Leven – an awesome place!
• Enrichment, water quality targets, solutions
• Recovery in Quality & Ecosystem Services
• Climate Change & Resilience
What I’ll cover…

3. Grasmere (1970)
Blelham Tarn
(1945)
Bassenthwaite
(1990)
Windermere S & N
(1943)
Esthwaite Water
(1945)
Currently ~ 450 lake years of data
CEH’s Long-term Lake Observatories
Derwent Water
(1990)
Loch Leven (1968)
>70 years
50 years
>25 years

4. Scotland’s largest shallow lake
loch area 13.3 km2
maximum depth 25.5 m
mean depth 3.9 m
altitude 107 m a.s.l.

5. Internationally-important
wild brown trout fishery
Photo source: Jamie Montgomery

6. Internationally-important nature
reserve (RAMSAR, SPA, NNR)
Photo source: Scottish Natural Heritage

7. Important site for tourism (Loch Leven
Castle & Mary Queen of Scots)
Photo source: Historic Environment Scotland

8. 8
Loch Leven: tourism & recreational opportunitiesRecreationImportant site for recreation (Heritage
Trail, RSPB bird reserve, cafes)
Map source: TRACKS

9. Scotland’s Flagship Freshwater Observatory
Measurements covering…
• Physics (water temperature, water clarity)
• Chemistry (N, P, Si, pH, DO, etc.)
• Biology (phytoplankton, zooplankton, macrophytes,
benthic invertebrates, fish)
Length of dataset: 50 years (1968 onwards)
Sampling frequency: fortnightly
Nutrient loading data: 1985, 1995, 2005, 2015
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
TPconcentration(µgL-1)
0
50
100
150
200
250
300

10. Key datasets collected by others
• Weather since 1968 (Kinross Estates)
• Optical properties since 2007 (University of Stirling)
• Palaeolimnology: diatoms, macrofossils 1750 - 2005 (UCL)
• Macrophytes 1821 - 1999 (Various)
• Fish catches daily since 1900 (Kinross Estates)
• Bird counts monthly since 1967 (SNH)
Ecosystem Service Data
• Angler numbers daily since 1900 (Kinross Estates)
• Water supply daily since 1850 (Tullis Russell)
• Tourist visitor numbers daily since 2004 (HES & RSPB)
• Heritage Trail users (SNH) - monthly since 2008

11. History of enrichment
1992 ‘Scum Saturday’ cost
local businesses ~ £1M
• Declines in macrophyte habitat for birds
• Declines in angling (fish kills & reputation)
• Reduced tourism

12. Setting Water Quality Targets
“The extreme depth to which such plants as Nitella opaca and
Fontinalis antipyretica will flourish may roughly be estimated by
multiplying by four the greatest depth at which one can see the
gravel at the bottom, when looking over the shaded side of a boat
about midday in the summer, when the sun is shining brilliantly, the
water being perfectly calm, and the boat still.”
West G. (1910). In Murray & Pullar’s Bathymetrical survey of the Scottish fresh-water lochs. Volume I
LLCMP targets:
Total phosphorus 40 µg l-1
Chlorophyll a 15 µg l-1
Secchi disc depth 2.5 m

13. Identifying Cause of Eutrophication
P input measured every 8 days for 1 year
Nutrient loading surveys: 1985, 1995, 2005, 2015

14. 1995 P Loadings
Runoff
54%Sewage
37%
Rainfall
5%
Wildfowl
4%
Bailey-Watts & Kirika (1999)
Source
Estimated annual TP
output (tonnes)
Runoff 4.5
Sewage 3.1
Rainfall 0.4
Wildfowl 0.4
Total 8.4
Estimated annual P
output (tonnes)
Source
1985: Industrial pollution
1995: Sewage & agriculture (diffuse pollution)
2015: Diffuse pollution (agriculture, storm overflows)

15. Responses to P loading reductions

16. Recovery in TP concentrations
• TP reductions in 1970s
• Increasing 1989-1994
• Further recovery since 1995
External loading reductions a success
Recovery over many years not a simple decline
LLCMP target
Carvalho et al., 2012

17. Reductions in Harmful Algal Blooms
2016

18. Aquatic plant coverage into deeper water
Potamogeton praelongus
re-appeared in 2014

19. Improved habitat for birds
Carss et al., 2012
0
200
400
600
800
1000
0
500
1000
1500
2000
2500
3000 Pochard
Pochard Scotland

20. Enhanced Fishing Quality
2013 CPUE of brown trout
Enhanced Catch Per Unit Effort
More large fish caught (catch-release)
2014 CPUE of brown trout

21. Boosting Tourism & Recreation
Visitor activities
(n= 500, Source: TRACKS)
>200,000 visitors per year
(Source = SNH)
Visitors attracted by:
1. Landscape aesthetics
2. Birds
3. Historic monuments
Photo Analysis
(n= 1470, Source: Flickr)

22. http://openness.hugin.com/caseStudies/LochLeven_Habitat
Anders Madsen
(Hugin Ltd.)
Loch Leven Fishing BBN
Select year and change probabilities:
1. Change habitat quality to see
impact of achieving WFD target
of good status on fishing quality
2. Change reputation to see the
effect on fishing service (boat
effort).
Predicting future fishing services
• What is the future
sustainability of the fishery?
• Will there be an increased
demand for fishing boats?

23. Climate change

24. 1970 1980 1990 2000
56789
airtemp spring
year
airtemperatureC
1970 1980 1990 2000
1112131415
airtemp summer
year
airtemperatureC
1970 1980 1990 2000
5678910
airtemp autumn
year
airtemperatureC
1970 1980 1990 2000
01234567
airtemp winter
year
airtemperatureC
Climate change: air temperature
warmer
Warmer springs,
autumns and winters
2-3 °C warmer
warmerwarmer
Data Source: Willie Wilson, Loch Leven fishery
Ferguson et al., 2008. J Applied Ecology, 45, 193–203

25. Climate adaptation: reduce nutrients further!
http://www.snh.gov.uk/docs/A1675513.pdf

26. Contributors
Linda May, Iain Gunn, Bryan Spears, Helen
Woods, Alanna Moore, Ian Winfield
Andrew Tyler & Peter Hunter, University of
Stirling
Claire Miller, University of Glasgow
External partners – including Kinross Estates,
Loch Leven Fishery & SNH
Laurence Carvalho
Freshwater Ecology Group
laca@ceh.ac.uk
www.ceh.ac.uk/staff/laurence-carvalho
Hydrobiologia (2012): 681