It’s a Solunar New Year!

With the start of a new lunar year a few weeks ago, this is a good time to revisit the topic
of “Solunar theory.“ This theory, first formally described almost 100 years ago, suggests
that movement and feeding of fish and wildlife are affected by the position of the sun and
moon (and tides when relevant). The theory combines the impact of various solar and
lunar factors to identify peaks in fish and wildlife activity.

Imagine a graph plotting the combined solar and lunar factors against time, with waves
rising and declining with the movement of the sun and moon. Multiple peaks may occur in
a given 24 hour period, with the highest called the “major” time and the others “minor”
times. The intensity of major times varies between days, and in theory the best day of the
week to fish could be predicted.

Solunar values are highest (major times) when the moon is directly above or below a
given location, with minor peaks at moon rise and moon set. A full or new moon increases
the score, as does sunrise or sunset close to the major or minor time. The exact math is
beyond the scope of this article, but for those interested, in more technical terms, the
quantities required for computing peak solunar times are the elliptic longitudes of the Sun
and Moon, the right ascension of the moon, and the local sidereal time of the observer’s
position.

Solunar tables are available from various print and online sources, and several smart
phone apps are available for predicting solunar peaks. Since solunar values are a function
of geographic location, mobile apps for determining best hunting and fishing times for a
specific user location are especially useful.

The remaining question is whether Solunar theory is an accurate predictor of fishing or
hunting success. It is likely that for far longer than 100 years fishers and hunters have
recognized that the phase and location of the moon were important, even without a
numerical calculation. It is generally believed that the solunar charts are a relevant factor
to be considered, in combination with factors like wind, temperature, etc. Experienced
fishers and hunters often have their own opinion based on their own experience.

Other scientific research supports the impact of lunar gravitation on living things. Just like
human bodies are guided by circadian rhythms, studies have shown that the behavior of
fish in a controlled environment is influenced by the moon cycle. Although the
gravitational pull from moon has a minimal effect in comparison to the Earth’s gravitational
pull, moon gravity clearly impacts ocean tides, and even the movement of tectonic plates.
It would almost be surprising if the moon did not affect living creatures. Research has
shown that even humans can sync up to the moon cycle if they don’t get enough sunlight
– and while this may seem like a minor change, there is an observable difference between
the moon’s 12.4 hour cycle and the sun’s 12.2 hour cycle. It is not surprising that lunar
gravity impacts living things and this research beyond the fishing community further
supports solunar theory!