Conclusions:
I. Some Mermaids are not Sharks.
II. Every Sharks can be Dolphins. Statements:

From Statement I. Only a few Sharks are Dolphins (I) + Some Dolphins are Mermaids (I) → No conclusion. Hence conclusion I does not follow. Only a few Sharks are Dolphins → Some Sharks are Dolphins (I). Hence conclusion II does not follow.   From Statement II. All Mermaids are Dolphins (A) + Only a few Dolphins are Ships (I) → No conclusion. Hence conclusion I does not follow. Only a few Dolphins are Ships (I) + Some Ships are Sharks (I) → Probable conclusion → All Sharks can be Dolphins (I). Hence conclusion II follows.   From Statement III. No Shark is a Ship (E) + Few Ships are Mermaids (I) → Some Mermaids are not Sharks (O*). Hence conclusion I follows. Only a few Dolphins are Sharks → All Sharks can be Dolphins (I). Hence conclusion II follows. From Statement IV. All Mermaids are Sharks (A) → I.I. → Some Mermaids are Sharks (I). Hence conclusion I does not follow. No Dolphin is a Mermaid (E) + All Mermaids are Sharks (A) → Some Sharks are not Dolphins (O*) + All Dolphins are Ships (A) → Probable conclusion → All Sharks can be Dolphins (I). Hence conclusion II follows.