Using fieldwork, this study investigated the endogenous issues of fishermen's livelihood vulnerability on Naozhou Island, Guangdong. Existing literature shows that current studies focus on external factors such as the resource reduction, climate impact, policy changes, and fishermen's mode of operation to explore the vulnerability of fishermen's livelihoods to reveal the resource-based impacts of fishermen's livelihood difficulties and to explain the impacts of exogenous factors on fishermen's livelihoods. However, to some extent, these studies have neglected fishermen's internal problems and failed to understand fishermen's perspective on whether the improvement of capital can offset fishermen's production inputs and improve their production relations. The study on Naozhou island found that the existing studies have ignored the endogenous problems of the fishermen's livelihood vulnerability; in the era of collective economy, each fisherman's family had a small boat, but the fishermen joined together to work for the "state" on a big boat. Currently, the market economy has ordered this type of cooperative relationship to disappear. Owing to the characteristics of marine fishing operations, everyone must help each other in cases of difficulties when going to sea. In the same boat, the crew members may be immediate or distant family members to avoid malicious harm. However, if production tools require high investment and fishery resources are scarce, cooperation is no longer important. Whoever has more money to purchase large ships has a greater opportunity to control the scarce fishery resources, which is essentially the change in production tools that led to a breakdown in production relations. Although fishermen still talk about traditional relatives' contact, the situation of "As soon as the ship arrives, there is nothing left" has made fishermen realize that competition is the essence of relationships in their fishing villages. Fishermen's mobility, combined with the outflows and reflows created by various realities at the time of the survey, further demonstrates that fishermen, as the labor force, are not able to participate in the market competition of labor factors, nor are they able to get rid of the fishing skills inherited from their parents. They want to leave behind their status as fishermen but have to rely on the status of fishermen for basic labor security. All of these aggregate into endogenous forces, ranging from the inputs of fishermen's production tools and their own skills to the ambiguity of their age and identity. This constitutes an endogenous mechanism for the vulnerability of fishermen's livelihoods, which offers a disincentive effect of institutional arrangements on fishermen's withdrawal from marine production and exacerbates the predatory exploitation of marine resources fueled by modern consumer markets. Consequently, it is difficult to determine the effectiveness of marine ecological protection policies. Research has shown that, based on Marx's theory of Productivity and Relations of Production, the vulnerability of fishermen's livelihoods is inherent in their own insurmountable rapid increase in productivity and their failure to establish relations of production that are adapted to the needs of productivity, which creates tensions in human–sea relations. Therefore, to solve the vulnerability of fishermen's livelihoods, it is necessary to start from the cultural specificities of fishermen, reform their relations of production from the inside out, update their skills, establish effective organizations, and gradually alleviate the tensions in human–sea relations to construct a community with a shared future for mankind and the ocean.

1 最新统计数据显示，2021年全国水产品捕捞产量为1 295.89万t，同比下降2.18%；2021年年末全国渔船总数为52.08万艘，比上年减少4.2417万艘，同比下降8.14%；2021年渔业人口为1 634.24万人，同比下降5.03%，其中传统渔民比上年减少38.28万，同比下降6.89%。这些下降趋势在未来还将继续（农业农村部渔业渔政管理局 等，2022）。