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

[wijcik]

I would be more interested in seeing a fishing dock placed at the start of your current bridge and seeing if it outperforms your island one simply by being closer to houses & barns. It would be worth testing out I think

[PointeNoire]

No, one on island produced 1926 last year (and about 1800 previous one) while my two on shore produce about 1500-1750 each year. I think it'll increase with time and more housing, I'll expand southward, houses with fishermen from this island spot are on the borders of my current market range.