I don't think a semicolon is right here. Are you proposing this?
"He spent a sabbatical conducting field work on Trinidad and Tobago; and in Suriname."
That sounds very odd indeed — I wouldn't say the sentence with a semicolon-sized gap in it and reading it with one is jarring.
There's nothing wrong with the original sentence. When I read and say it I do so with the same cadence as "He spent a sabbatical conducting field work on Bermuda and in Suriname." The "and" in Trinidad and Tobago is just coincidence — it's not part of the sentence structure. If a reader doesn't know that Trinidad and Tobago is a place then perhaps the sentence's "in x and y and on z" would provoke them into finding this out.
> He spent a sabbatical conducting field work on {Trinidad and Tobago} and in {Suriname}
Could be clearer, although "On Trinidad and Tobago" doesn't make sense. "In Trinidad and Tobago", or "On Trinidad", or "On Tobago", sure, but Trinidad and Tobago are two islands (and many smaller)
"He spent a sabbatical conducting field work on Trinidad and Tobago; and in Suriname."
That sounds very odd indeed — I wouldn't say the sentence with a semicolon-sized gap in it and reading it with one is jarring.
There's nothing wrong with the original sentence. When I read and say it I do so with the same cadence as "He spent a sabbatical conducting field work on Bermuda and in Suriname." The "and" in Trinidad and Tobago is just coincidence — it's not part of the sentence structure. If a reader doesn't know that Trinidad and Tobago is a place then perhaps the sentence's "in x and y and on z" would provoke them into finding this out.