Incorporating Biodiversity into Food Systems Modeling: Fisheries-Nutrition Linkages in Ghana

Abstract

Food systems in low- and middle-income countries are rapidly transforming due to population growth, urbanization, rising consumer incomes, and changes to built and natural environments. These trends are associated with a triple burden of malnutrition, that is, concurrent undernourishment, micronutrient deficiencies, and overnutrition. Previous research has established the critical role of fish and seafood in healthy diets by contributing animal protein, omega-3 polyunsaturated fatty acids, and micronutrients, including vitamin A, calcium, iron, zinc, and iodine. In Ghana, the country focus of this dissertation, fish and seafood represents nearly 70% of all protein-rich food expenditures. However, fish and seafood consumption and its nutrient composition can vary based on biodiversity factors, such as species/genera (e.g., mackerel versus tilapia or crab) or production sources (e.g., marine or freshwater; wild capture or farmed). These variations are relatively underexplored as nutrition research often ignores biodiversity by combining species/genera and production sources into a single fish and seafood group. This dissertation research uses primary qualitative data and secondary data collected in 2016-17 as part of the seventh round of the Ghana Living Standards Survey (GLSS 7) to improve our understanding of fish and seafood biodiversity in the food system and its influence on consumer behaviors.

Aim 1 is a qualitative study that characterizes the fish and seafood consumption behaviors of women living in Accra, Ghana and assesses how biodiversity in the food system impacts them. Using thematic analysis, we interpolated four interrelated themes that link their consumption behaviors to the greater food system ('tastes and preferences', 'health and nutrition', 'social, cultural, and religious factors', and 'cost and convenience'). The sample reported consuming 22 fish and seafood species/genera in traditional soups and stews, which were generally perceived as beneficial to health and nutrition and worth the premium over other protein-rich foods. However, there were widespread concerns about marine and freshwater sources related to climate change, imports, and illegal fishing practices.

Aim 2 assesses the contribution of fish and seafood species/genera to dominant patterns of food purchasing behaviors in Ghana. We generated these patterns by applying principal component analysis to nationally representative household food expenditure data from the GLSS 7. Then, we used multivariable regression analysis to assess the cross-sectional associations between those patterns and socioeconomic status. We found that freshwater fish species/genera were correlated with starchy staples, fruits, and vegetables in the ‘traditional’ pattern, which was associated with lower socioeconomic status. Marine fish species were correlated with refined cereal and grain products, dairy, and packaged beverages in the ‘modern’ food pattern, which was associated with higher socioeconomic status.

Aim 3 assesses consumer demand for fish and seafood species/genera by estimating household responses to income and food price changes. We used household expenditure data from the GLSS 7 to specify a censored Quadratic Almost Ideal Demand System (QUAIDS) model. Then, we used the model outputs to derive the income and own- and cross-price elasticities of demand for each fish and seafood species/genera. Our findings confirm that fish and seafood is inelastic to income and price changes, but we observed heterogeneity in consumer responses by species/genera.