The scenario you've described involves a fishing society on coastal land that exists independently of any recognized government or larger political authority. Whether scientists or political theorists consider this society to be a "country" depends on how we define a country.
Generally, a country is recognized as a sovereign entity that possesses defined territory, a permanent population, a government, and the capacity to enter into relations with other states. By this standard, a society that does not have a formal government or recognition from larger governments may not qualify as a country in the traditional sense.
However, some might argue that the society has characteristics of a community or a collective with its own social structure and cultural identity, which could challenge conventional definitions of nationhood. In international relations and political science, there are also concepts such as "de facto states" or "autonomous regions" which recognize entities that function independently without widespread formal recognition.
In conclusion, while the society you described may not meet all the criteria to be officially classified as a country, it may still represent a form of social organization that holds significance in terms of cultural identity or community autonomy.