1. Climate clarification
Albedo
Definition: the extent to which an object reflects light from the sun
Range of values: 0 to 1
Impact: high albedo, high reflectance
less solar energy absorbed by object

2. Typical albedo Snow 0.8-0.9 Tundra shrubs 0.2 summer 0.6 snow covered
Amazon forest
Amazon ranchland 0.18
Boreal forest
Boreal grass

3. Feedback loops
Warming will melt sea ice and promote growth of shrubs in the arctic
Puddles and shrubs have lower albedo (reflectance) than ice and tundra
Puddles and shrubs will warm up rather than reflect solar energy
Warm puddles and shrubs will increase ice melt and promote further shrubification

4. Feedback effects on climate
Impact of Deforestation
Ranchland has higher albedo
0.18 vs 0.13
Surface absorbs less energy
Cooling effect
Ranchland has much less evaporation
Warming effect
Net effect
WARMING
+- indicates effect of forest
on temperature

5. Feedback effects on climate
Impact of Deforestation
Grassland has higher albedo
0.20 vs 0.08
Surface absorbs less energy
Cooling effect
Grassland has slightly less evaporation
Warming effect
Net effect
?????
+- indicates effect of forest
on temperature

6. Humans, fisheries and tough conservation decisions
A Case study:
Lake Victoria’s Nile perch fishery and cichlid biodiversity

7. Lake Victoria
Largest lake in Africa (68,800 km2), seventh in the world by volume.
Tanzania, Uganda and Kenya all share the lake and its resources, but regulations governing resources are different in each country.
Annual catch: ,000 tons bringing in US$250, ,000.
2 million people depend directly or indirectly on fishing activities.

8. European History
1858 “discovered” by John Speke
- sparsely populated region
- subsistence fishery (small native species)
1902 – colonial government links lake to Mombasa
1930 – Europeans had deforested watershed
- planted tea coffee sugar tobacco cotton
- population had exploded
- urban centres provided market for fish
1950 – native tilapia commercially extinct
English introduce non-native tilapia
1955 – English introduce Nile Perch

10. Fishing history – the early days
Ngege
Catfish
Haplochromines

11. Impacts of Nile perch
1955 – introduced to Lake Victoria
Haplochromines 83% biomass
Nile perch %
1980’s Nile Perch 80% biomass
Haplochromines <1%
Massive loss diversity
400+  200 species

12. Fishing history
– the next 30 years
Decline has continued

13. Lake Victoria – summary so far
The local multi-species fishery is now dominated by 3 species and supplies an international market
200 endemic Cichlid species were driven to extinction in 30 years
Overfishing, industrial and agricultural pollution, an increasing human population and noxious water weeds, all threaten the sustainability of Lake Victoria.
The Nile Perch is being overfished.

14. What happened next?
Intensive fishing led to a resurgence of native species
Haplochromine cichlids, particularly pelagic species recovered
Three areas acted as refugia
- Wetlands and rocky habitats
- Hypoxic areas
- Satellite lakes

15. The future? But current environment is very different
New fauna will differ in richness,
composition and ecosystem function

16. The sociopolitical context
Award winning documentary by
Hubert Sauper is a tale about
Lake Victoria, humans in the north and south, globalization,
corporate corruptness, and fish.
The following are excerpts
from the film.

17. If goal is to conserve the remaining cichlid diversity what should conservation biologists do?
Options?

18. ‘The Roundtable’
The Lake Victoria Fisheries Research project has organised fisheries managers to work on quantifying the fisheries stocks of Lake Victoria and has also managed to bring together scientists from the 3 countries to exchange views and identify gaps in research and recommend how to deal with those gaps.
Planning for the lake’s future (economically and biologically) may proceed with a two-pronged approach:
Managing the fisheries to maintain the greatly increased yields and;
“The fisheries managers”
Conservation of the remaining indigenous species.
“The conservation biologists”

19. Lake Victoria Fisheries Organization (LVFO) comprises stakeholders whose objective is to “protect and restore the lake”. Where is the political power? Whose interests are being protected? Given the population pressure and the industry/political pressure what would YOUR conservation strategy be?
*Are all stakeholders interests being represented equally? The answer to this is clearly, “NO”.

20. Possible avenues for biodiversity conservation
Conservation of habitat and biodiversity will only succeed if water quality is improved –
nutrient levels and toxic contamination should be controlled
Stock management strategies linked to rational regulation of fishing effort are needed
Representative habitats in the lake should be conserved with focus on high diversity areas, refugia, satellite lakes and shoreline wetlands
Development of an integrated basin wide plan
- international cooperation is necessary to regulate nutrient influx and fishing pressure