This is most evidently a metaphor. The thing to keep in mind when analyzing literature/poetry is that if you see figurative language making comparisons/drawing parallels between two differing things--instances where the meaning is not literal such as how injustice is not really a fire and has no flames--it's a safe bet you'll have on your hands a metaphor.
Answer:
They try their best to patch it up and begin to fight off the sharks with an oar.
Answer:
The central idea of the book is, aspects of good citizens
