In 1926 John Alden Knight postulated some folk lore he picked up in Florida and proceeded to attempt a refinement, giving it the name Solunar (Sol for sun and Lunar for moon).
Knight compiled a list of 33 factors which influence or control day-to-day behavior of fresh and salt-water fish. Everything was taken into account that could possibly have any bearing on the matter.
One by one the factors were examined and rejected. Three of them, however, merited further examination. They were sun, moon and tides. Surely the sun could have no effect since its cycle was the same day after day, whereas the observed activity periods of fish were apt to be present at most any time of the day or night.
When the original research was being done only the approximate time of moon up - moon down were considered. Gradually, it became evident that there were also intermediate periods of activity that occurred midway between the two major periods. Thus the more evident periods were called major periods and the two intermediate periods, shorter in length, were called minor periods.
One convincing experiment was when Dr. Frank A. Brown, a biologist at Northwestern University, had some live oysters flown to his lab near Chicago. Oysters open their shells with each high tide, and Dr. Brown wanted to see if this was due to the change in ocean levels or to a force from the moon itself.
He put them in water and removed them from all sunlight. For the first week they continued to open their shells with the high tides from their ocean home. But by the second week, they had adjusted their shell-openings to when the moon was directly overhead or underfoot in Chicago.
Knight first published his tables in 1936. Then, and today, one must calculate the precise times from each table taking into account the geographic location (east or west) of a base point (Time Zone), and adjusted for Daylight Savings Time when appropriate.
To substantiate the theory, John Alden Knight acquired the complete details surrounding the capture of record catches. Both individual large fish ... and large numbers. He examined approximately 200 of these catches. Over 90 percent were made during the new moon when the effects of the solunar periods are the strongest.
During 1935 to 1939 Knight made extensive studies of game birds and animals and found they also responded to the solunar periods.
Because of the interaction between the many lunar and solar cycles, no two days, months or years are identical.
When a period falls within 30 minutes to an hour of sunrise or sunset you can anticipate great action. When you have a moonrise, moonset, moontransit, or moonminor during that period the action will be even greater. And, finally, when the above times occur during a new or full moon, you can expect the best action of the season.
If the barometer happens to be steady or rising, if the temperature is favorable (15 degrees higher than water temp) then long and active response to a period can be expected.
Research has shown that a natural day for fish and many other animal species differ from our own. Their biological clock appears to coincide with lunar time, which is the time that it takes for the moon to reappear at a given point.
THE BEST FISHING AND HUNTING TIMES
(A Message From the Author)
Its no secret that fish and game tend to feed during dawn and dusk (sunrise and sunset). What amplifies the activity
is the effect of a moonrise, moonset, moon transits, and moon minors, plus the specific monthly periods of New and Full
Moons. When the times coincide with a moon event the action can be spectacular. These periods are quite important when
calling predators since unlike Deer and Elk, they tend to rest in places not accessible by us humans.
All wildlife knows what to expect of the weather, and any bird, animal or fish can sense the approach of a storm. Cold fronts moving through drive all fish deeper and render them inactive. Adverse temperature, abnormal water conditions, all sorts of things will offset the effects of periods.
It goes without saying that if there are no fish or game present, you will not be successful. Plan your days on the water or in the field so that you are where the game is most likely to be during the periods.
For a good article on Factoring in the Weather Extreme Bass Lures has a helpful one.