The most common and most likely answer to this crossword clue is the 6 plus 3 letter word BERING SEA
I've seen this crossword clue in The Guardian
B
E
R
I
N
G
S
E
A
More clues leading to the result BERING SEA
- Creatures overcoming resistance with each lot of cold water
- Swimming bears in eg water off Alaska
- Busy worker securing wheels needs a cold drink
- Water and transplant bergenias
- Direction and date announced to arrive at vast body of water
- Cold water as beer, gin rum!
- Social worker screening calls by Australian in part of the North Pacific
- Banger is falling apart traversing European body of water
- Gains beer after fermenting quantity of water
Buddy explains!

The straight part
We know that "part of the North Pacific" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of the north pacific = bering sea.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.