The moon’s influence on trout fishing often gets brought up in conversations between fishermen. Trout fishermen are no exception, although they are less concerned about it than sea fishermen. When I head out the door to go fishing, I never take the phase of the moon into consideration. If I have the time available, and if the weather is nice, I fish.
It is well documented that some species of fish are more likely to feed during the full moon. Visual hunters like trout can see their prey easier so they can continue to hunt throughout the night. Small baitfish can better see plankton, and approaching danger so they too are more active. During the brightest nights, all fish are simply more active.
If the fish have been up all night feeding. It can be speculated that they less need to feed during the hours of daylight. Spending the energy to grab a mayfly or darting in-line spinner is unnecessary when the trout already ate their fill the night before. So the day after a full moon, the trout can be harder to catch simply because they have been feeding all night.
Night fishing under the full moon
Nighttime trout fishing when the moon is full can be the most productive. It offers several advantages over fishing on darker nights. The biggest advantage is the full moon simply makes everything easier to see. Less likely to trip over the boulders walking to the fishing spot. While fishing it is easier to see the fish, most accurately the ripples and swirls created by trout as they are hunting. Casting is also easier. Once your eyes have adjusted, it should be possible to see your line and lure, allowing for more accurate casts and presentations.
I know of one elderly fly fisherman who only goes night fishing over the full moon.
Even when night fishing, it is still important to match the hatch. Try and figure out what the fish are feeding upon. Trout often surface feed on nocturnal insect hatches. Typically on moonlit nights, Caddis imitation flies work well. I like something big and obvious, with a white indicator hairs of the back. Simply because it is easier for both myself and the trout to see. For the spin fishermen, a fly and float could be worth a try.
When night fishing, most fishermen use big and dark lures. I agree with that assessment. I like to use floating lures or unweighted streamers. My thinking goes that lures on the surface are easier to see, they contrast against the night sky. When fly-fishing my favorite streamers to use are Wooly Buggers and Rabbit flies.
When spin fishing, I usually start with a floating Rapala, and work is slowly. Sometimes I use a black vivid to make the jerkbait even darker. I rarely start with it, but if the fishing has been slow, I like to try a small popper or flatfish lure. They dance across the surface with plenty of action. Hopefully, enough to attract the attention of a hungry trout.
Do not be afraid to experiment. Painting an in-line spinner black has worked for me before. Despite it running sub-surface. There are tales of fishermen catching large lurkers fishing mouse or frog imitations under the cover of darkness. I like to cast them across deep pools, or along the edge of lakes. A slow steady retrieve seems to work well.
Tidal impact on trout
The moon creates tides, and the full moon creates the largest tides. Less well known is that tides affect all bodies of water. From the largest Oceans to the smallest ponds there will be a tidal influence. While in the sea the tidal range can be large, in ponds it is impossible to notice with the naked eye.
Unless you are fishing in the lower tidal zones of the river, the tide is not really relevant for trout fishing. Even the Great Lakes have a maximum of two inches of tidal range. The influence from Air Pressure and wind has a much greater influence on lake levels.
When fishing in the tidal zones. It is worth knowing that some species of baitfish run during the full moon (or during the highest tide). Trout like all predators follow the food. So when the baitfish are running, the fish hunting trout will lie in wait hoping for an easy meal.