SAN FRANCISCO – Researchers working around Kenya’s Lake Victoria, a fishing
community where locals battle high rates of disease and a depleted fish
stock, have found that human illness exacerbates unsustainable fishing
Before this study, published Monday in the journal Proceedings of the
National Academy of Sciences, it has been known that a toxic environment is
known to create health problems for people.
While challenging the long-held assumption in environmental research that
human disease provides a natural check to environmental exploitation and
demonstrates a new way that poor human health may harm the environment, the
study suggests that quality healthcare could have benefits beyond human
populations and help people manage their environment and the sustainability of
“Studies have suggested people will spend less time on their livelihoods
when they are sick, but we didn’t see that trend in our study. Instead, we saw a
shift toward more destructive fishing methods when people were ill,” said
Kathryn Fiorella, the lead author who was a doctoral student in the lab of
professor Justin Brashares at the University of California, Berkeley, during the
study and now a postdoctoral scholar at Cornell University.
Understanding the links between human and environmental health is critical
for the millions who cope with recurrent illness and rely directly on natural
resources for sustenance.
To study these connections, Fiorella spent three months of each year of her
graduate studies at Lake Victoria, a place where health and the environment are
intertwined in complex ways and have been for decades.
Lake Victoria transformed after British colonists introduced Nile perch, a
predatory fish, to the lake in the 1960s to support commercial fishing. Nile
perch quickly dominated the lake and caused the extinction of hundreds of native
During the 1980s and 1990s, commercial fishing grew around the lake and Nile
perch started to decline, so regulations were enacted to save the fishery.
During the same time, the HIV epidemic was spreading throughout East Africa.
As Lake Victoria’s fishing community grew sicker, the environmental exploitation
of the fishery worsened.
To explore how illness was altering fishing practices, the researchers
tracked 303 households living on Lake Victoria by interviewing them four
different times over a year. They collected data about household health and
fishing habits and looked for trends during times of sickness and good health.
Among active fishers, the study found limited evidence that illness reduced
Instead, ill fishers shifted the methods they used. When ill, fishers were
more likely to use methods that were illegal, destructive and concentrated near
the shoreline, but required less travel and energy. They were also less likely
to use legal methods that are physically demanding, require travel to deep
waters and are considered more sustainable.
“When people are chronically ill, they have different outlooks on the
future,” Brashares said. “That different outlook means that they increasingly
rely on unsustainable methods because they’ re focused on short-term gain.”
“Healthy people, it turns out, are better for the environment,” Richard
Yuretich, program officer for the US National Science Foundation’s Dynamics of
Coupled Natural and Human Systems Program, which funded the research, was quoted
as saying in a news release from UC Berkeley.
“When you feel well, you can plan the tasks you need to accomplish more
carefully. But when you’re sick, you often just want to get things done fast,
with the result that you may be more wasteful. This project illustrates the
complex relationships we have with the world around us.”