With a focus on Kenya, researchers from the University of Toronto are exploring how child development - including muscle movement, language skills, emotional responses and social interactions - is improved by fish consumption and, indirectly, by fisheries-generated income.
The study, published recently in the journal World Development, looked at communities on Kenya's Mfangano Island on Lake Victoria, which is home to some 30,000 residents.
They found that the consumption of a native, sardine-like species called omena (Rastrineobola argentea) - a historically underexploited species - leads to better child development outcomes than consumption of Nile perch, an invasive species introduced to the lake in the 1960s. That's likely because omena contain higher levels of micronutrients such as omega-3 fatty acids, iron, zinc and calcium.
"Understanding the different pathways linking fishery access and early childhood development is key to designing a more comprehensive approach to tackling the effects of changes in fishery access on human well-being," says Ranaivo Rasolofoson , an assistant professor of planetary health in the Faculty of Arts & Science's School of the Environment and lead author of the paper.
While Nile perch are popular commercially because they are large, fleshy and have fewer bones, the researchers found no significant benefits for child development outcomes. Nile perch are also an invasive predator that has had a significant impact on the lake's ecosystem and, since they are higher up the food chain, Nile perch typically contain more environmental contaminants.
The researchers also show that past studies into the benefits of fisheries on the lake did not adequately take into account the positive indirect impact of fisheries on child development. They show that fisheries income - either through the sale of caught fish or working at processing plants - also improves child development outcomes by improving families' overall diets.
While the authors did not fully investigate the pathways between income and benefits to children, they point out that fishing income can affect early childhood development in many ways, including by enhancing parents' mental health and parenting behavior, and by making school-related expenses and enrichment items like books and toys more affordable. It may also help by reducing parental stress and ameliorating harsh, authoritative and unresponsive parenting brought on by economic hardship.
"There's a lot of research that shows fish consumption is good for child development," says Rasolofoson. "To my knowledge, our study is the first to quantify the contribution of fishing income alongside that of fish consumption on child development."
Rasolofoson, who began the study as a postdoctoral researcher at Cornell University, co-authored the paper with researchers from the United States Agency for International Development, the Ekialo Kiona Center in Kenya, the Kenya Marine and Fisheries Research Institute, and the University of California, Berkeley.
The study included 210 children aged two and under from 206 households that both consumed fish and gained income from fisheries. Subjects were surveyed nine times over two years.
Rasolofoson is hopeful the findings will help guide public policy. As the authors point out, disentangling the pathways between fish consumption, fisheries-related income and health is critical in developing effective programs and policies for improving nutrition, early childhood development and nature conservation.
"My hope is that decision-makers will see the research and realize that locally available, non-invasive, environmentally friendly species like omena can be very nutritious," he says. "That could lead to, for example, sustainable management of these species and their promotion as part of a healthy diet."
As a professor of planetary health, this study is just one facet of Rasolofoson's overall research.
"Planetary health is about the impact that environmental or natural system degradation has on human health," he says. "In other words, what is the impact of climate change, heat waves, more intense and frequent storms or deforestation?
"This research looks at the connection between aquatic systems and human health. It's a small piece of the big picture but we think it's an important contribution."
