I'm pretty sure it refers to fisherman, which, of course (in our current politically corrupted language), is sexist and "fisherperson" is pretty awkward, hence the truncation. I haven't seen many female deckhands on Deadliest Catch.
In my world, women goin’ fishing pretty much would ruin the whole point of the activity.
That reminds me of my favorite PC word, “Sewer,” as in person who sews. The language is truly going down the drain.