There is a long debate on whether the Moon Phase (or some call it Moon Cycle) affects fishing catch. While there are different theories surrounding this topic, one notable factor seems to the effects of tides.
Stronger currents around big tides turn on the feeding switch for most game fishes. And the biggest (spring) tides occur around full and new moons. Whether the light of the moon is a factor or not, tide most likely is in various fisheries. And tidal flow is influenced by moon phase. Taken in that context, most professional fishermen agree that moon phase becomes critical.