I know that a semicolon should be used before a transitional phrase and a comma after, but what about in a sentence like this:

"This study has; however, demonstrated comparable rate, further supporting the use of traps"

or

"Abundance was; however, higher in the BGS trap"

Is this incorrect? If so, would it be correct to remove the semicolon and comma completely?

Connective adjuncts like "however" when used in the middle of a sentence are set apart by commas (called 'delimiting' commas), not by a semicolon. A semicolon is used to mark the boundary between independent clauses within the same sentence:

(1) "Ed was, however, not good at English grammar".
(2) "Kim was good at history; however, she was not good geography".
(3) "Kim however was not good at mathematics".

In (1) a semicolon would be wrong; all that is required to mark the left and right boundaries of the connective "however" is a pair of commas. In (2) the semicolon is required to mark the boundary between two independent clauses within the same sentence, and a comma is then used after "however" to complete the punctuation. In texts with 'light' punctuation, the commas can be omitted altogether, as in (3).

So in your examples:

(4) "This study has, however, demonstrated comparable rate, further supporting the use of traps".
(5) "Abundance was, however, higher in the BGS trap".

In (4) and (5) there is only a single clause, so a semicolon would be wrong. Just as in (1), all that is required is a pair of commas to mark the boundaries of the connectives.


PaulM

That makes sense, thank you!