1. Senior Research Scientist Environmental Chemistry Division
Dr. (Mrs.) Ruby Asmah
Senior Research Scientist
Environmental Chemistry Division

2. Effects of Climate Change on Volta Lake Resources (VOLTRES)

3. Outline of Presentation
Collaborating Institutions and Research Team
Background and Introduction
Objectives
Methods
Activities for year 1
Challenges

4. Collaborators/Research Team
Collaborating Institutions
The CSIR Water Research Institute
Department of Biosciences, Aarhus University, Denmark

5. WRI Research Team Dr. Ruby Asmah (Project Coordinator/Lake Ecosystem)
Dr. Hedrick R. Dankwa (Fishery Biology/Aquaculture)
Dr. Emmanual Obuobie (Climate Change/Hydrology)
Ms Deborah Ofori (PhD Student – Hydrology/WQ)
Mr. Emmanuel Mensah Tetteh Doku (PhD Student-Fisheries/Aquaculture)

6. Danish Research Team
Dr. Hans Estrup Andersen (Soil Science and Hydrology)
Dr. Dennis Trolle (Biological Science and Environmental Engineering)
Dr. Torben L. Lauridsen (Fisheries)

7. Funding/Duration Funding Duration
Danish Foreign Ministry and DANIDA Fellowship Centre
Duration
Three (3) Years

8. Background and Introduction
The Volta Lake:
Formed in 1964 by damming of the Volta River
Surface area of the 8500 Km2
Volume at maximum level is 149 Km3
Total length of 400 Km
Located between 1° 30’W and 0° 20’E and Latitude 6° 15’N and 9° 10’N

9. Background and Introduction (Cont’d)
The Volta Lake:
Total drainage area of 394,000 km2
Source of livelihood for more than 1230 communities

10. Background and Introduction (Cont’d)
Lake Volta (Cont’d)
The Lake is the main source of freshwater fish in Ghana
Accounts for about 15 % of total annual domestic fish production
85 % of inland fish production
80 % aquaculture production in Ghana.
A source livelihood for riparian communities
Main/Other uses of the Lake are:
Hydroelectric power generation
Potable water supply
Irrigation
Transportation

11. Background and Introduction (Cont’d)
Climate change is projected to impact widely across
ecosystems,
societies and
economies, increasing pressure on all livelihoods and food supplies (IPCC 2007).
Its implications for fisheries and aquaculture, is said to be enormous (FAO 2010).

12. Background and Introduction (Cont’d)
Short term impact to freshwater fisheries is anticipated would come through:
incremental changes in water temperature,
hydrological changes in rainfall affecting nutrient mobilisation and other pollutants (FAO 2007).
lower dry season water levels (FAO 2007)
Changes in reproductive processes, larval and juvenile development and survival of fish (Pankhurst and Munday 2011).

13. Justification
Nearly all the models used by IPCC agree that the frequency of intensive precipitation will increase for the Volta Lake and Entire West Africa Region (IPCC, 2007).
Between 1°C and 1.5 °C rise in air temperatures in the Lake region are expected by middle of the 21st century (Obuobie et al., 2012, Obuobie and Sasu-Asante, 2013; Jung, 2006; Andah et al., 2004)

14. Justification (Cont’d)
The Lake’s role in supporting livelihoods and nutritional welfare is critical in a country where fish is estimated to account for up to 60% of its total animal protein requirement and contributes 6% of GDP
Ghana is listed among the countries that are most vulnerable to climate change because of the high vulnerability of the country’s fishery sector to climate change (Allison et al. 2009).
Africa’s response to climate change is believed will be dictated by how well it is understood by its people (BBC WST 2010).

15. Main Objectives
To assess the impacts of climate change on hydrology, water quality, primary production and fish production of the Lake and improve the understanding of the lake ecosystem functioning
To build and strengthen local capacity in climate change research and biophysical modelling

16. Specific Objectives
Develop future climate change scenarios for the Volta basin (400,000 km2) including Lake Volta;
Adapt biophysical and ecological models to the Volta basin and Lake Volta for understanding the Lake ecosystem functioning;
Quantify the indicative effects of climate change on water, sediment and nutrient inflow as well as primary and fish production in Lake Volta;

17. Specific Objectives (Cont’d)
Build knowledge and tools for improving the understanding of lake ecosystem functioning and fish production;
Build capacity in climate change research and biophysical/ecological modeling in Ghana;
Raise awareness and facilitate adaptation to climate change by informing local, regional and national stakeholders on prognoses for future inland fish production

18. Project Hypothesis
Climate change, particularly increased temperatures, will alter the hydrology, water quality, primary production and fish production in Lake Volta.     

19. Materials and Methods Sampling Sites Black Volta at Chilbrungo
White Volta at Nawuni
Oti River at Sabari
Volta Lake at
Yeji
Kpando Torkor
Adawso (Afram Arm)

20. Yeji
Black Volta – Bole Bamboi
Black Volta - Bui

21. Materials and Methods (Cont’d)
Data Collection
Primary and secondary data on the following:
lake inflow- and outflow-volumes,
inflow concentrations (sediments chemistry),
lake water chemical, physical and biological data (e.g. temperature and dissolved oxygen profiles, nutrients, chlorophyll a, phyto- and zooplankton biomass, fish biomass).
Sampling frequency is monthly

22. Methods and Methods (Cont’d)

23. Work Package 1 (WP 1)
Climate change scenario development and catchment modeling
Analyze climate outputs of all RCMs for the 2 (Upper and lower limits) of the 4 representative concentration pathways (RCPs) used in the CORDEX program.
The period will be taken to be the baseline, considering the existing fish catch data, while the period is considered the future.
Upgrade existing Volta Basin SWAT model (VB-SWAT) to include components on sediment and nutrients and improve soil data through sampling and analysis of essential soil parameters in major soil types

24. Work Package 1 (Cont’d)
Adapt the upgraded VB- SWAT model to simulate the inflow of sediment and nutrients into Lake Volta through the processes of calibration and validation.
Simulate and quantify the effects of changes in precipitation and temperature (climate change) on the flow of water, sediment and nutrients into Lake Volta.

25. Work Package 2 Lake ecosystem modeling
Set up of a 3D model of lake hydrodynamics and biogeochemistry based on data from WP1.
Field data collection and laboratory analysis.
Test and validate lake models on field data and remotely sensed data.
Make future projections on lake physics and primary production under different climate forcings providing input to WP 3.

26. Work Package 3 Fish Productivity
Collect historical information on fish catches and establish empirical relationships to lake water level fluctuations and water temperature
Field data collection.
Analysis of stored gut material and mapping of seasonal food habits of the most important fish species.
Establish empirical relationships between biomass and temperature, oxygen concentration and primary production. Estimate fish mortality rates.

27. Work Package 3 (Cont’d)
Set up of EcoPath, an ecosystem model for the higher trophic levels (Christensen and Pauly, 1992) to explore the dynamics and sensitivity of climatic forcing on fish productivity using data from WP 2 on future lake physics and primary production.
Make predictions of future climate change effects on the fish stocks by using established relationships between fish catches/fish productivity and environmental factors.

28. Expected Outputs
Downscaled future climate scenarios over the Volta Basin
Biophysical/ecological models (watershed, lake and fish models) adapted to the Volta basin and Lake Volta,
Indicative effects of projected climate change on water, sediment and nutrients inflows to Lake Volta and consequences for fish production;

29. Expected Outputs (Cont’d)
Ghanaian scientists trained in climate change impact research; (v)
Journal publications;
Four post graduates (2 PhDs and 2 Mphils)
Improved awareness at local and national level of climate change effects and adaptation in relation to inland fish production

30. Dissemination Nationally Internationally through policy briefs,
workshops for local and national stakeholders, and
seminars covered in print and electronic media
Internationally
Publications in peer reviewed journals,
Presentations in international and regional conferences, and
Project website

31. Challenges
Availability of reliable long term secondary data on water quality
Delays in acquisition of equipment for the project

32. Way out
Use of remote sense data – these will be calibrated with field data

33. TNAKS FOR YOUR ATTENTION