With focus on the case of Naejeo Village of Ongam-ri, Daedeok-eup, Jangheung-gun, which is renowned for the production of “silk maesengi (seaweed fulvescens)” or “chal(sticky)-maesengi,” this paper seeks to discuss the value of sustainable fisheries by reviewing the introduction and settlement processes of maesengi aquaculture in the community and patterns of adaption to the changing situations by local fishermen. This research introduces not only the backgrounds for the introduction of maesengi aquaculture to the community but also the efforts of local fishermen to adapt themselves to a new type of fishing industry from various perspectives. In the past, the villagers allowed the degradation of their sea in return for bigger financial gains. In contrast, maesengi aquaculture required clean seawater for higher productivity. The community streamlined its traditional communal labor system to resolve the generational conflict on how to use the limited offshore space most effectively. It also rediscovered the value of the ancestors’ fishing practices that treasured harmony between nature and mankind as well as the value of the ancestors’ experiential knowledge of the industry. The community rituals of local fishermen have changed according to the changes in their livelihood, which can be referred to as a good example of local fishermen’s cultural adaptability. The local fishing community has changed its staple aquaculture products to maximize financial gains as in many other modern communities. Note, however, that the community’s current maesengi aquaculture can be regarded as the community’s ultimate effort to realize harmony between nature and mankind in the sense that the aquaculture requires a high level of natural integrity. The environment-friendliness of maesengi aquaculture shows how we can solve many problems facing the country’s various types of aquaculture and achieve sustainability throughout every corner of our society. The value of sustainable fisheries is not just an economic gain. Rather, the value is universal in terms of the preservation and inheritance of our fishing villages’ unique ways of life and intangible cultural heritage. The maesengi aquaculture does not give rise to problems that are quite common in other types of aquaculture including aquaculture of other kinds of seaweed. The community’s maesengi aquaculture is completely based on community consensus when it comes to resources management and utilization. Local residents as a whole now have a different perspective of the local fishing industry. Therefore, they maintain the community’s traditional fishing rituals with some necessary changes. All these facts prove that a community’s livelihood is closely related to the spiritual and cultural force that keeps a community united and up-to-date instead of being mere means of securing economic survival. Going forward, research will have to be conducted in various areas with keen attention paid to the cultural value of maesengi aquaculture and its contributions to the coexistence and mutual benefit between oceans and people.