10th Drop: Human and Natural system dynamics of fisheries in Lake Victoria

~ HI THERE!! Hope everyone is doing well and here is another interesting article I found :)

Ecosystem services and Social system dynamics?

I ended off last week's post with a point on how there is a need for greater understanding of the interactions between the physical aspect of ecosystem services and the human aspect of ecosystem services exploitation/ degradation. But indeed such an understanding is definitely easier said than done. Today I will cover an article, similarly on Lake Victoria, which attempts to understand the complexity of such interactions between humans and the lake ecosystem with reference to the provisioning ecosystem service of fisheries. Hopefully this article will reinforce the complexities, but also highlight the potential in understanding coupled ecosystem and social system dynamics.

Coupled Human and Natural system dynamics, Lake Victoria

The importance of the provisioning ecosystem service of fisheries within Lake Victoria for the millions of people on the lake have been emphasized time and time again. While there are plenty of research on the different aspects of Lake Victoria's fisheries system (eg. stock dynamics, lake biodiversity, eutrophication, fishing communities and market systems) these research have largely been separate and narrowly focused. Downing et al. (2014) thus seeks a more multi-disciplinary approach to understanding the fisheries system dynamic as a whole so as to capture the system-wide chain reactions/ effects that result from disturbances in a particular aspect.

This is done through developing a qualitative model of the lake's social-ecological system of the fisheries, using expert knowledge from different fields and from respective social and ecological subsystem stakeholders. The model is then investigated through a qualitative loop analysis where feedback loops - pathway of interactions that go from a component and back to itself, through other components defined in the system - in the system were identified. These feedback loops were assigned +ve or -ve signs depending on whether it "reinforces" process or "self-regulates" process respectively. Feedback loops identified were then classified into nutrient 'enrichment' loops, eutrophication loops and exploitation loops to investigate how disturbances through such forms might have system wide chain reactions. Detailed findings about the different feedback loops are explained in the article itself.

Here are some thoughts that I had from the article:

1) Complexity of coupled ecosystem and social system dynamics/ interactions

• authors emphasized the interconnection diagram between ecosystem and social systems
• highlighted that there are multiple pathways to a single phenomenon
• complexity of the entire system: changes can initiate and drive different dynamic regimes
• eg. high connectivity of fisheries between owners and markets, adaptability of fishers and access to both international and domestic markets...allow for changes in stocks
• possible +ve impact on social-economic system where fishers are more robust to the loss of the international market
• but also -ve impact on ecosystem where more stocks are vulnerable to exploitation, dampening the self-regulating exploitation feedback loop 
• despite such complexities, high connectivity and multiple pathways of interactions...it also represents multiple tools to management

> The article has clearly articulated the complexity and interconnections surrounding ecosystem service of fisheries in Lake Victoria. It is definitely beyond just ecological understanding of the ecosystem itself but also involves interactions with social-economic system of markets and livelihoods. The importance of understanding such interactions could not be further emphasized by how even slight disturbances can result in unpredictable changes that cascade throughout the entire system via feedback loops. Such understanding is even more important, and hopeful, for management of ecosystem services as it highlights the presence of multiple tools to a problem. For example the article highlights the need to go beyond just fisheries stock management and for more explicit eutrophication and biodiversity management to address concerns relating to the ecosystem service of fisheries production.

2) System Heterogeneity and Adaptive Management

• authors also emphasize that dominant processes shaping lake dynamics are heterogeneous in both space and time
• temporal changes to ecosystem service of fisheries production in Lake Victoria is not foreign: sudden collapse of native Tilapia species and dominance of introduced Nile Perch
• spatial heterogeneity in terms of eutrophication effects across the lake: inshore-offshore gradients
• heterogeneity + complexity of the system highlighted above + unpredictable seasonal and interannual variations in weather due to climate change => significant management challenges
• authors highlight the need to first understand the different spatio-temporal scales at which different processes dominate first
• such understanding should go hand-in-hand with understanding the interactions between ecosystem and social system dynamics
• need for adaptive management approach that recognises and embrace such heterogeneity
• adaptive management (Ostrom 2009) requiring stakeholders to work together and develop a common understanding and knowledge of their system
• making of management choices as key part of the learning process
• knowledge constantly developed from changes resulting from different choices made
• hence constantly adapting management/ policies

> Such system heterogeneity, connectedness and complexity is not unique to just Lake Victoria but definitely prevalent throughout other ecosystems (wetlands, forest and even agricultural areas) in Africa. Hence there are significant challenges and complexities surrounding these ecosystems and the management of ecosystem services. A clear understanding of the processes at work - in terms of scales at which they dominate and the possible cascading effects as a result of interconnections - will thus go a long way in helping to formulate appropriate management plans. The suggestion of adaptive management is definitely a valid one but not without its own challenges. The first big question would be the involvement of multiple stakeholders and ensuring equity in representation. Secondly significant will and commitment will need to be invested by all stakeholders in the development of a comprehensive understanding and management plan of the lake's coupled ecosystem and social system. 

THANKS for reading this fairly wordy post :P Hope that this article has been as interesting for you as it has been for me! :)

~Till Next Time~

Photo of Lake Victoria in 1985 by Vintage National Geographic