Socio-ecological feedbacks in fishery systems

Check out the great video William & Mary did on my research in Uganda!  

Over 1 billion people depend on fish as a primary source of protein, and fisheries provide employment and income for hundreds of millions.  Fisheries represent complex systems of human and natural interactions: fishing effort is shaped by economic, political, and regulatory concerns, while the number of fish caught is driven by climatic, biological, and technological variables.  I seek to understand the feedbacks that shape fisheries systems, from natural variation in fish abundance to the effect of market forces on fisher behavior to the role of fisheries resources in social well-being.

Dr. Cullen Hendrix (College of William and Mary) and I are exploring the relationships between fisheries and social conflict in the Lake Victoria basin in East Africa.  In collaboration with the National Fisheries Resources Research Institute (NaFIRRI) in Uganda, we seek to answer the following questions:

1. What is the importance of mukene (also known as dagaa, Rastrineobola argentea) to local and regional food security?
2. How does variability in catch of mukene affect its price and that of substitutable commodities in surrounding villages, major fishing ports, and the captial, Kampala?
3. What is the impact of social conflict (including protests, riots, and civil war) on fishing effort, fisher migration and behavior, and food prices?
4. How does the fishery for Nile perch affect the fishery for mukene?

GIS at Lake Victoria

We are working with fisheries scientists and natural resource managers at NaFIRRI to develop a Geographic Information Systems Center in Jinja, Uganda.  This Center provides technical training to scientists and students and is an important tool in our understanding of spatial dynamics of fisheries.  Dr. Stu Hamilton at the Center for Geospatial Analysis at William & Mary is playing an important role in providing instruction and technology for this project.

Are you a University of Denver student interested in spending a month studying natural resource management, forestry and agriculture, or fisheries in Uganda?  Contact me to learn about summer 2014 opportunities!


Lake Victoria, the largest lake in Africa, is one of the most vibrant systems on Earth. In the 1950s, Nile perch and tilapia were introduced to the Lake to support a growing regional fishery. Perch and tilapia populations soon dominated the lake ecosystem, providing income for fishers and a product for an ever-growing export market driven by demand from Europe. However, Nile perch survived by decimating native cichlid fishes and catfish, driving many species to extinction. Mukene, the local name for a native minnow, was an indirect beneficiary of this change in the lake food web: as cichlids and catfish were depleted, populations of mukene increased.

Mukene are a critical link between the ecology of Lake Victoria and the human populations that depend on the Lake’s resources for food and income. The mukene fishery is the largest, by volume, in Lake Victoria. However, it is not desirable for the European export market; most sales of mukene occur locally, and the market price is far less than that of Nile perch or tilapia. The contribution of mukene to regional food security, defined as “when all people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life” (World Health Organization),  has not been quantified. One link between the mukene fishery and food security may be indirect: fish catch provides cash to fishers, and cash is used to purchase other resources such as poultry, vegetables, and grains. A direct link also exists: when more expensive food resources became unaffordable, village households increase consumption of mukene as a coping mechanism.

There is a significant need to improve understanding of the links between human and natural systems in the Lake Victoria basin. A rapidly growing human population on the lakeshore is accelerating anthropogenic impacts on the ecosystem. More than 40 million people live in the basin, and ecosystem services provided by the Lake, such as drinking water, food fishes, and irrigation for agriculture, are threatened by changing land use, deforestation, pollution from agriculture and sewage, and overfishing. Malnutrition rates, especially in women and children, are high in fishing villages. While Nile perch has provided employment and income for tens of thousands of East Africans, catch of perch has declined over the past decade, foreshadowing a classic fishery contraction resulting from unsustainable levels of fishing.  If the Nile perch fishery collapses, there could be important implications for the lake ecosystem, the mukene fishery, and local food and livelihood security.

Food security is inherently tied to civil unrest; political instability and violence have affected food and livelihood security for many communities. Conflicts in Burundi, Democratic Republic of Congo (DRC), Rwanda and Uganda have caused widespread population displacement in the Lake basin and threaten human security. To date there exist strikingly few studies of the effects of civil conflict on fisheries.  My research (Hendrix and Glaser, 2011) indicates conflict significantly suppresses fish catch which harms food security both directly, via decreased food availability, and indirectly, via loss of livelihood among fishers. Food insecurity, in turn, is an accelerant of political violence.

Conflict that takes place near fishing communities may reduce fish catch through at least four processes: redeployment of labor, population displacement, counter-insurgency strategy and tactics, and illegal encroachment into national fishing grounds. However, conflict far from fishing communities may increase demand in regional markets, leading to higher catch. Anecdotal evidence suggests a complicated regional relationship between conflict and Lake Victoria fisheries. Neighboring conflicts, particularly in the DRC, drive up demand for dried mukene.  Mukene is an ideal “fast food” source of protein – it does not spoil and is lightweight – for people who are either fleeing conflict zones or are directly involved in fighting. But the impact of higher demand in DRC on prices of mukene and hence food security in Uganda is not known.