Answer:
A semicolons NEVER should be used to try to create a "pause" longer than that achieved by a comma. If you can use a period correctly, then you can use a semicolon correctly. A semicolon is used just like a period, but it is used to separate two complete sentences when the sentences are closely related in meaning
Explanation:
Animals being in captivity is bad for their instincts. In captivity, animals lose their more wild side that's in touch with their original and natural environment. Unless an animal (specifically whales in this case) is injured and cannot be in the wild, they should not be kept in captivity.
I think the last revision is the answer, as both are independent of each other and tell us two separate clauses in the same sentence