When we say that cause and effect relationships can be developed in a chain, it means that a succession of effects from a cause can cause new effects.
In other words, a chain reaction of cause and effect relationships means that cause 1 will generate effect 1, effect 1 will cause effect 2, which means that effect 1 has become cause 2 and has generated effect 2. Successively, effect 2 will generate effect 3 which in turn will generate effect 4 and so on.
It’s saying the sea “licked greedy lips” the Sea doesn’t have lips so it’s a type of personification because it’s giving a non living thing humanistic characters.