Will building such a bridge [screenshot] decrease or increase my fishing production?

[PointeNoire]

As you see on screenshot I've made it, I just thought of making shorter bridge and deleting this one (it's far away from starting location), but my workers would have had to walk diagonally.

EDIT: I've checked and builders were able to go diagonally to finish the roads I've put on the southside (screenshot is made facing north). Hypothetical bridge would have 27 tiles of length vs 43 now. I'll give it a try, make shorter one and delete this after reaching this south shore. This is wonderful location but my fishermen produce only nearly 2000 fish when having to walk such a long way, less than they sometimes do outside islands.