Desert Island Life from Scratch

A marine biologist drifts to a desert island due to a shipwreck. Faced with unknown biological threats and endless loneliness, how will he use limited supplies to achieve long-term survival? Ps: There will be a lot of real survival knowledge interspersed in the novel, let's experience the feeling of having too much knowledge. If there is any incorrect knowledge, please correct me and discuss. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.