6th Drop: Effects of climatic changes on Ecosystem Services, Lake Tanganyika

~ HEY THERE!! Hope the past few days during reading week has been good for everyone :) As promised, here is another post for this week!

Ecosystem Services and Climatic Changes

I believe we have covered quite a fair bit on the different provision and regulating ecosystem services related to water in Africa and how they can be related to Payment-for-ecosystem services management approach. While I did not cover specifically on cultural and supporting services, I believe that they too can be approached in a similar manner to regulating services - valuing them based on their provision benefits (i.e. Happiness & Cultural learning for cultural services and nutrient levels & agricultural productivity for supporting services). Again the key issue revolves around how an accurate value can be assigned to these services and subsequently how a Payment-for-ecosystem approach can effectively take into account societal context to encourage proper resource management and ecosystem conservation.

Now beyond just anthropogenic changes that have been affecting ecosystems, a much bigger concern in this day and age would be the effect of climatic changes on our ecosystems and hence the services that we are so reliant on! This is partially because there are significant uncertainties and gaps in our understanding of future climate change, much less the extent of the impact it will have on ecosystems and their services. Which brings me to the post today which will cover a case study of how climatic changes have affected a key ecosystem service in an African lake, Lake Tanganyika.

Decrease in aquatic ecosystem productivity in Lake Tanganyika

O'Riley et al. (2003) discuss about the biotic and ecosystem-scale responses to climate change that have been exhibited in Lake Tanganyika. More specifically the authors compare Carbon isotope records from sediment cores of the lake, with changes in climatic effects such as surface-water temperature and wind velocity to suggest that climatic changes have resulted in an approximate 20% decrease in primary productivity of the lake. This translates into a 30% decrease in fish yields thus explaining the decline in pelagic fishery landings (previously attributed to unknown environmental factors).

Here are some personal reflections:

1) Complex effects of climatic changes on ecosystems and ecosystem services

• Increased surface-water temperature and decline in wind velocity - stability of water column and reduced mixing depth
• Diminish deep-water nutrient inputs to the surface waters (disruption of supporting service?)
• And hence decrease in primary productivity, affecting pelagic fishes 
• Such complex interactions are hard to predict, but more importantly mitigate 
• Global anthropogenic activities can affect specific ecosystems and their services as well
• These impacts can often be subtle, progressive and hence potentially dire

> Climate change effects are expected to be significantly impactful within the tropics, and hence the African continent. Such significant and complex effects on ecosystems and their services, combined with the heavy reliance of this densely populated region on these services should be of significant concern to leaders within the continent. And hence, proper understanding of these impacts on ecosystems and mitigation measures should be taken.

2) Potential for payment-for-ecosystem services approach to management of Lake Tanganyika?

• Possibility of valuing the supporting service of primary productivity of the lake by relating the service to fisheries productivity?
• Considering that impacts are due to global climate change, solutions may not just specifically address issue of primary productivity in Lake Tanganyika
• Carbon Credits as a possible solution? (Though might be too generic for Lake Tanganyika)

> A specific payment-for-ecosystem services approach may require a more detailed study and understanding (as highlighted in previous posts as well). More importantly if we take into consideration the impacts of global climate change on ecosystem services, more general forms of payment-for-ecosystem services approach of carbon credits might likely be more appropriate and effective.

THANKS for reading and hope this post was helpful to you! :)

~Till Next Time~

National Geographic Society Photo by Saskia Marijnissen