A new study led by Cornell University examines how temperature affects fishing behavior and catches among fishing households in Cambodia’s interior, with important implications for understanding climate change.
The research, which used household surveys, temperature data and statistical models, found that when temperatures rise, people fish less often. At the same time, the study authors indirectly found that stocks of fish and other aquatic foods also increase with temperatures, resulting in slightly larger catches each time populations fish. Without careful analysis, it would appear that overall fish catches appear to be unchanged every year, when in fact a more nuanced dynamic is at play.
The study highlights why it is necessary, when studying changing environmental conditions, to include human behavior as well as ecosystem responses; both are key variables when considering how climate change affects rural livelihoods, food production and access to food.
The article, “Fishermen’s Response to Temperature Change Reveals Importance of Integrating Human Behavior in Climate Change Analysis,” published April 30 in the journal Scientific progress.
“This study highlights the importance of integrating human behavior into climate change modeling,” said Kathryn Fiorella, assistant professor in the Department of Population Medicine and Diagnostic Sciences and Master of Public Health Program at the College of Veterinary Medicine. “To accurately predict the impacts of climate change, we need to know the effects on ecological systems, as well as the effects on the people who use them.”
In the study, Fiorella and colleagues used data provided by partner organization WorldFish, which collected survey data every two months over three years for households in Cambodia, which has the highest per capita consumption. of continental fish to the world. WorldFish collected information on how often people fished, how much time they spent fishing, and what method they used.
The researchers used remotely sensed temperature data over the same three-year period, which revealed a range of 24 to 31 degrees Celsius (75 to 88 degrees Fahrenheit). Researchers also monitored rainfall and flooding.
“Temperatures in the study range compare to regional climate projections in the region, which suggest between 1.5 and 2.5 degrees Celsius [2.7 to 4.5 F] temperature rise above the average of 28 degrees Celsius [82.4 F]”Said Fiorella.” What we have observed is in the range of what we might expect under climate change scenarios. “
The researchers found that the time spent fishing per trip and gear choices were not affected by temperature, but fewer people were fishing as temperatures rose.
They also analyzed the fish catches. It turns out that, with constant effort, the fish catch per trip increased as temperatures rose, which meant the ecosystem became a bit more productive when it got warmer. The same pattern was true for other aquatic animals, such as frogs or snakes, and aquatic plants. However, without taking into account the effects of temperature on human behavior, it might have seemed that temperature had no effect.
Researchers suspect that the frequency of fishing decreased as temperatures rose due to competing interests. “These households have a range of different activities that they are engaged in at the same time,” Fiorella said, noting that many of them are rice farmers or run small businesses. At the same time, heat can also be a factor, she added.
Fiorella added that large swathes of the population are migrating to cities or neighboring countries for work, and that this dynamic could keep them away from fishing.
“Ultimately,” she said, “understanding both ecosystem responses and people’s responses to temperature will be fundamental to understanding how climate change affects people who depend directly on natural resources for their lives. food and their income. “
The study was funded by the Cornell Atkinson Center for Sustainability and the WorldFish Paddy Fisheries Improvement Project, which is supported by the US Agency for International Development.
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Material provided by Cornell University. Original written by Krishna Ramanujan. Note: Content can be changed for style and length.