Gary Engberg Outdoors

gengberg January 18th, 2012

Lunar Position Affects on Bass Fishing
Ralph Mann - fisheries biologist and In-Fishermen Contributor
Duffy KopfAfter reading Ralph’s article, I couldn’t help thinking that many anglers wouldn’t actually read the article as it is based on scientific research. Unless you have been involved in scientific research, how could you know about some of the concepts laid out in the article. I will make every attempt to simplify so that all can truly understand the effects of moon position on fish. I did leave some things out for simplicity’s sake.

In 1992 Ralph Mann wrote an article regarding how lunar position affects bass fishing. The catches he and his buddies made tended to follow the prediction of solunar theory. His results scientifically did not meet the research criteria.

Ralph thought that his catches where better during a major or minor period when everything else was equal.
*Major period is when the moon is directly overhead or directly below a given
longitude.
*Minor period is then the moon is at a 90 degree angle from a latitude.

He shows some positive relationships between good catches and the solunar periods, but these were just not strong enough to hold up. He just hadn’t collected enough data. Now Ralph has a much larger sample and the conclusions he makes are backed by statistically sound research. Now he can say with confidence that his research demonstrates a strong link between moon phases and bass catch rates.

Ralph’s new data (1992-2010) includes
*2500 outings
*10,466 hours of fishing
*8900 bass of 12″ or more caught
*Used info from US Naval Observatory to get precise majors and minors
*Bass 5 lbs. and up were analyzed separately (some think that solunar periods
have more of an effect on larger bass.
*Caught 40 bass from 8 to 10.8 lbs.
*He also noted water temperature, wind direction/speed, and sky conditions

Abundance, position and vulnerability of prey will determine a bass’ eargerness to attack. Adult bass feed only when the conditions are favorable and will become inactive when opportunities to feed are poor (allowing them to conserve energy).

It is interesting to note that Ralph found that ½ of bass have an empty stomach even when food is abundant in the summer. Other facts are interesting:
*Bass tend to feed in low light conditions (this condition will overrule lunar
effect).
*Fish Mate App for iPhone is a good source of determining majors and minors.
*If you have pinpointed a group of fish, fish them during a major if possible.
*Many anglers concentrate on weather, shade and barometric pressure.
*Fishing trips were on ponds, impoundments, reservoirs mostly in Texas with
some in Louisiana and New Mexico.

When do bass bite best? It would be nice to have a simple answer to this. Mann concludes that the best times are as follows: 1. major+1 (hour following the midpoint of a major), major+2, minor and minor+1. His highest catch rate was: minor and minor+1 and he thinks that minors may have a bigger effect on catch rates.

The lowest catch rate is the hour before a major or a minor. It looks obvious that the bass’ activity levels peak somewhere between a major and a minor. The implications for the angler is to start fishing shortly after a major and go hard until two hours after the minor.

Fish size and water type information also yielded some interesting tidbits:
*Ponds (small water) produce best and have the smallest fish.
*Second place on the production scale are power plant lakes. It is interesting that
there is no relation to moon phases in these lakes.
*Large reservoirs have even a lower catch rate, but contain larger fish.

Ralph Mann thinks (not scientifically) that invertebrate (animals without a backbone)
movement is affected by the lunar phases.
*Increased invertebrate activity levels will lead to higher activity levels in other
species such as a bluegill and the other fish that feed on the bluegill.

Ralph also addressed the different seasons and how the effect from the moon affects bass. He fished about the same number of hours from March - November. He also concludes that during winter and spring, there is little lunar influence. In May - November his hourly catch rates were linked to the lunar periods. He concludes that this also shows the lunar effect on invertebrates.
*Spawning show no lunar effect
*Catch rate peaked in April (remember, he is in southern states) around the spawn
and then stabilized through summer and early fall with small bass increasing
slightly because they are now larger.
*Large fish catch rates in winter are low, but stable.

Best times to fish in May are: major+1 and minor. June: major+1 and major+2 and following hours. Summer peaks where in the hours around the major and minor. Catch rates declined in November with peaks at minor+1 and minor. December indicates that you need to fish before and after minors.

Ralph and his friends had 702 night trips and averaged .52 fish/hour as opposed to a catch rated of .87 during the day. Night fishing peaks occurred around the majors with the lowest catch rate around the minor, but this was not very significant.
*Fish are affected at night by brightness (moonlight) and they feed better with
more of the ambient light.
*If a full moon corresponds with a major period - get your butt on the
water!

Do you like to get up early to fish because you think it is the best time? Maybe you need to think again. Ralph defined Dawn as 30 min. before sunrise and an hour after. Dusk was defined as 1 hour before sunset to 30 min. after. Fishing at dusk was better than fishing at dawn.

How about the weather? This changed my thinking a little.
*Catch rates lower with clear sky.
*Partly cloudy is best
*Overcast - average
*Fastest bite is in the rain
*Wind direction - not much effect
#S, SE, N, and NE winds slightly better
*Wind speed more important - the catch rate goes up the windier it gets.
*Very windy conditions have a high catch rate.
*Cold water (49-58 degrees) has slowest bite rate, 59-68 = better, 69-78 =best,
79-88 = decrease, but the bite got better at even high temperatures.

Other observations made as a result of the research:
*The longer in a day you fish, the better the catch rate (you figure things out).
*A strong bite, no matter what triggers it will be followed by a period of slow
fishing that may last up to 12 hours. A large portion of the bass population is
inactive to allow themselves to digest the food eaten during the hot bite.
*Lunar influence is more potent in waters where the food web is based on
invertebrates and sunfish rather than shad. Plankton and invertebrates are most
influenced by lunar forces that causes panfish and bass to be more active.
*Other forces (such as light and weather) can overwhelm lunar effects.
*Go fishing in the evening around a major or minor. As fish become more active,
use faster, more aggressive presentations.
*Use of this information for tournament anglers or for planning a fishing trip.

*Keep in mind that the difference between the slowest hours and peak times
amount to about two bass in a ten hour day. Even on good water, ½ of the hours
are fishless. Catching two bass per hour is rare.

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