China's gray zone actions in the East China Sea, Taiwan Strait, and South China Sea: A comparative study and impact on fisheries

China's use of the "gray zone" strategy in the East Asia region, employing coast guard, naval forces, and maritime militia, has drawn attention for its non-military tactics that escalate conflict without crossing into open warfare. This study examines China's gray zone actions in the East China Sea, Taiwan Strait, and South China Sea, focusing on their impact on fisheries in Japan, Taiwan, and the Philippines. This study reveals that China's gray zone actions significantly affect fisheries in the East Asia region, leading to reduced fishing space and declining catch volumes. Furthermore, China adapts its strategies across maritime regions based on regional capabilities to effectively allocate maritime power to different areas. This adaptive approach allows China to tailor its actions to specific contexts within the region. •China employs various gray zone actions in disputed waters to establish a new status quo.•The intensity and methods of China's gray zone actions vary by region.•It can be observed that China's gray zone actions adjust according to the perceived strength of its opponents in different maritime area.•China's gray zone actions might impact the fishing operations in the East China Sea, Taiwan Strait, and South China Sea.