A recent scientific investigation has uncovered the intricate link between climate change effects and how coastal fishers in southern Japan are adjusting to them.
A fresh study, released on Wednesday in the journal People and Nature, highlights the intricate dynamics of climate change impacts and the adaptive strategies of coastal fishers in one of the most affected places: the southern coasts of Japan. Rising water temperatures and strong northward ocean currents are rapidly altering the macroalgal habitats in these waters, as coral reefs, subtropical herbivorous fish, and other warm-water species extend their range north. This global trend, known as tropicalization, poses a threat to temperate ecosystems worldwide, impacting everything from macroalgal beds in Japan and Australia to seagrass meadows in the Gulf of Mexico and the Mediterranean, and changing the types of species present and the functions these ecosystems perform. Despite recognizing these shifts, there is limited information on how fishing communities are being impacted and adjusting, complicating effective management. This study aims to bridge that knowledge gap in sciences and policies.
The research was part of an international PhD project led by Dr. Xochitl Édua ElÃas Ilosvay at the Future Oceans Lab at CIM-University of Vigo, Spain. This study was supervised by researchers Elena Ojea and Jorge GarcÃa Molinos, with contributions from Naoki H. Kumagai of Japan’s National Institute for Environmental Studies and assistance from local community members, Kameyuki Seike and Kazuki Seike, during field research.
Interviews with over a hundred fishers from Shikoku
To gather insights, the research team conducted face-to-face interviews with more than a hundred fishers from 25 different fishing communities along Shikoku, Japan’s fourth-largest island. These communities were located in three regions with varying levels of exposure to tropicalization—from areas dominated by tropical corals in the south to mixed ecosystems in the center and the last remaining temperate macroalgal habitats in the north. “These fishing communities served as a natural laboratory to assess how well adaptation strategies reflect the varying degrees of ecological change,” Xochitl E. ElÃas stated. The aim was to determine if the fishers’ adaptive strategies were more shaped by the severity of ecological change (known as the “adaptation continuum”) or their socio-economic environment.
The findings indicated that fishers in the central region, which experienced more dynamic tropicalization, largely adopted adaptive measures (like cutting fishing costs or exploring new species), while in the other regions, many chose not to act at all. The absence of proactive measures among southern fishers, where tropical changes have been established for a longer time, contradicts the adaptation continuum theory, which posits that as impacts increase, fishers naturally shift from adaptive measures to more significant changes when those measures fall short.
The researchers believe that the earlier transformative changes in the south, such as quitting fishing, have resulted in a decline in the fishing population, as they only interviewed active fishers. Yet, the degree of exposure did not significantly impact the fishers’ readiness to embrace transformative change—this willingness seemed more dependent on their social and economic conditions. Households reliant on fishing for income and sustenance were generally more inclined to adapt, but less likely to make radical changes. On the other hand, those involved in coastal aquaculture showed greater enthusiasm for substantial changes compared to their counterparts in extractive fishing. This reinforces the necessity of addressing both climate change mitigation and social adaptation together.
Need for anticipating and applying adaptive strategies
As coastal fishing and aquaculture account for nearly half of Japan’s total fishing output and provide considerable employment in the sector, these findings emphasize the critical need for policies that incorporate environmental, socio-economic, and cultural factors, aiming to safeguard fishers’ livelihoods amid environmental changes. The study also accentuates the importance of conducting research in climate change hotspots to generate insights that could inform the preemptive and transformative strategies necessary for other parts of the world expected to encounter climate change impacts in the future.
