It’s no secret to those in the business and for those who stake their livelihood on harvesting wild fish: The lunar cycle plays a role in influencing the feeding behavior, thus influencing the catch!
The lunar calendar can predict a general fishing forecast based on moon phases, sunrise, and sunset data. Some species have different feeding habits, so it’s important to understand what causes each individual species to bite and at what times!
One direct effect of changes in moon phases is the amount of lunar intensity (Light) received by the earth. Additional light creates a more conducive hunting environment. Instinctively, pelagic (Migratory) species intensify their hunt during a full moon as the prey is easier to see and engage. In turn, fishing is much more effective and efficient during a full moon, for Sword & Tuna in particular.
An indirect effect of the lunar cycle on the marine environment is tide. There are many theories about how tides affect the behavior of marine life. Proven theories include the idea that increased tidal flow simply moves the animal more increasing catch, Lobsters in particular. Exaggerated tides prove effective with shellfish harvest as beds are exposed during low tide giving increased access. During the full and new moons, tides are higher, creating stronger current which is always important in influencing the bite. Common statistics show that fish are going to be more active 4 days prior to a full moon and 4 days following a new moon.
Crabs and the Moon: The first full moon in May kicks off the start of the season's peeler run which quickly turns into the first, and typically largest, soft crab run of the year. The peeler run is simply the time that crabs awaken from their winter slumber and head to shallow waters to molt. During the first run most of the peelers are females which did not reach their molt the previous fall. Those females are also looking to mate because the only time female blue crabs can mate is while she is in a soft crab state (molt). The full moon or even new moon is used as a guideline or an indicator that soft crabs supply should become more available.