As long as your's experitise is within 3 lvls of pumping and reeling you are ok. Also, at high lvls of those skills you may want a better fishing rod to help with damage, since higher level fishes got more hp, and also seem to change their behavier more often. When I had expertis of like 17-18 (the red and purple fishes) I was still fine with C grade fishing pole using shots, well, A grade rod would of helped more, orcource.
If your question is "Can i have lvl 5 expertise/pumping/reeling at 75 and still get fish?" Then yes you can.
Your expertise/pumping/reeling can only be leveled as high as 1/3 your current level. So, for example, a level 54 character can't go any higher than 18.