Certainly there are places around the world where
swordfish are caught without lightsticks but they are exceptions, not the
rule. The standard for swordfishing is fish the period of the full moon,
using a big squid (about a half pound or bigger - 175 to 200 grams), and a
lightstick of choice. But "there’s the rub" because there is no set
agreement on either size or colour. Green lights, four inches long,
however, are the most popular. More on this later.
During the mid-70’s off the coast of Miami, Florida,
Cuban longliners were using floating, amber burning kerosene smudge pots,
primarily to keep track of the drift of their relatively short long lines.
They quickly noticed that more swordfish were being caught directly
beneath the lighted pots. Shortly thereafter other fishermen started using
small battery powered Japanese lights and at the same time the somewhat
new Chemical lightsticks that had been developed by the American Cyanamid
Company, Swordfishing in the Straits of Florida became a Gold Rush.
Chemical lightsticks were actually developed by
American Cyanamid with the help of the United States government in order
to have a low heat, non flammable light which could be used in areas where
the possibility of fire was highly likely. Coincidentally, the design of
these lights also allowed them to be easily used under water. The light in
lightsticks is created by the interaction of an oxalate ester and an
activator. One of the chemicals was contained in a glass ampoule inside of
a plastic tube. When the plastic tube is bent or squeezed, the glass
ampoule breaks, allowing the chemicals to interact and create energy which
is emitted as a light source; green, yellow, blue, pink, white, or violet,
to name the most common. When exposed to light and, or moisture these
early lights lost their ability to activate and produce any light, and as
a result needed special packaging. These lights were individually wrapped
in tin foil, or in metal buckets containing three hundred or more lights
in a dark plastic bag. These storage requirements and the monopoly
guaranteed by the Cyanamid patents made these original lights very
expensive, costing a US dollar or more. None-the-less fisherman used
millions of these lightsticks in a variety of ways which increased
swordfish catches way beyond what many fisherman expected.
Sometimes they would be placed inside the bait and at
other times they would be placed at various lengths above the bait,
anywhere from a meter to several fathoms. Captain Jim Hardee, one of South
Florida’s top swordfisherman insists that about one fathom above a 200 to
300 gram squid is perfect. On a two week trip with him not too long ago, I
witnessed swordfish after swordfish come aboard, many with lightsticks in
their mouths. Knowing when and where to fish are also important. Currents,
counter currents, temperature breaks, and water colour changes all effect
fishing success. Finesse is probably the proper word for describing a
successful swordfisherman. Use fewer baits, but make sure each and every
one is perfect. Jim doesn’t seem to have a favorite colour but as with
most places around the world he uses green most of the time and from time
to time pink and blue. Colour preference sometimes is based on fisherman
preference as much as it is based on fish preference.
Arguments seem to centre around light intensity first
and colour second. After the basic patents held by American Cyanamid
expired, several companies entered the market. Omniglow, World Plastics,
and Lindgren-Pitman, Inc., the newest entry, all have added improvements
over the original lights. Because of this competition, both light and
colour performance continue to improve. Lindgren-Pitman, by using two
glass ampoules instead of one inside the plastic tube, has created a
lightstick with considerable more shelf life than was previously possible,
perhaps as much as 5 years. Furthermore, Lindgren-Pitman’s clear plastic
provides for as mush as a 30% increase in light output and its new
patented attachment which eliminated the need of using rubber bands for
attaching the lightsticks to the line have made this light one of the best
available. All of these innovations have led to more competitive pricing
which is less than half of what it was several years ago. This saving has
allowed fisherman to use more lights and experiment in newer ways in order
to find the perfect combination.
All of these changes and the existence of competing
products has fostered fisherman generated demand for higher quality and
more diversified lightsticks. Varying the types and quantities of the
chemicals can create lights which give off different intensities of light
for varying period of time. For example, some lights initially burn very
brightly but fade rapidly. Others seem to last longer. The goal is perhaps
to have a light which burns with a steady intensity over a six to eight
hour period, the normal period during which a long line is soaking.
Another simpler way to vary light intensity has been to simply change the
size of the lightstick of the amount of chemical in the tube.
Concerning this about three different sizes exist -
three inch lights, four inch lights, and six inch lights. The four inch
lights are by the most popular, however, in warmer more tropical climates
the six inch lights prevail. Gill net fisherman, particularly those
fishing in Chilean waters seem to favor the larger lights which are
attached directly to the nets at various locations. In contrast, the four
inch lights are much more popular in colder water regions, where the
lights are sometimes use a second night after being kept in ice or the
freezer between used. There four inch lights are also used for Big Eye
Tuna in several locations, most noteworthy are Venezuela and Uruguay.
Smaller three inch lights may allow for newer
breakthroughs. Because of the physical properties of light and the way it
dissipates in water, making lights larger to create more light doesn’t
offer very much promise. However, by using two or more smaller lights, the
effective lighted area can be increase much more than by using a bigger
light. For anyone interested in pursuing this in more depth;, they should
refer to FISHING WITH LIGHT by Ben Yami, available from Fishing News
Books, Ltd. Although this book contains absolutely nothing about fishing
for swordfish, it discuss the historical use of lights from the beginning
of time for about just about every species that most of us might be able
to name.
Ben Yami explains it as follows:
Evidently the extinction of light in water is many
times stronger than in air and a fishing lamp which can be seen from miles
away will be undetectable underwater at a distance, at most, of a few tens
of meters. This is due to the higher attenuation in water. Attenuation
consists of absorption, scattering and reflection. Absorption is the
conversion of light into another form of energy, e.g. heat. It occurs in
the water itself and in particular at the particles suspended in it.
Scattering and reflection are due to the same particles which also
determine the transparency of water. Scattering occurs even at the
molecules of the water itself.
The different wavelength of colour may help explain why
using different colored lightsticks may affect fishing success. Infrared
(a long wavelength) is absorbed and converted to heat very efficiently and
therefore travels only a very short distance in water. Red (a slightly
shorter wavelength) travels only a little farther. Therefore longer
wavelengths (red and infrared) will have only a small sphere of visible
light from an underwater source. The colours in the middle of the light
spectrum, green, yellow, and blue travel the best in water. At the other
end of the spectrum, ultraviolet (a short wavelength) is largely reflected
at a surface and is reflected, scattered and absorbed when introduced from
a source below the waters surface. Violet light (a slightly longer
wavelength than ultraviolet) also will not have a large sphere of visible
light under water although it will be better that red light. So what does
all of this mean? At least theoretically, and if a large sphere of visible
light is important, the following colors should work in descending order
(most light to least light) green, yellow, blue, orange, pink, and red.
This in part is born out by current usage. Through out the world, green
lightsticks are used twice as often as the next most popular colours, blue
and pink which are used almost equally. However many fisherman will attest
to the fact that under certain conditions, some of the other coloured
lights will out perform all of the others. Experimentation is constantly
needed in order to optimize fishing success.
Can swordfish actually see is another question which is
still debated from time to time. They have the rods and cones in their
eyes which indicate they should be able to see colors. One thing is
certain, they have great big eyes, big mouths, and big appetites.
In concluding it is worth mentioning that, success with
lightsticks is also correlated with moon phases. Fishing success seems to
pick up at an increasing rate as the moon rises, with the fish feeding
deeper and deeper. Upon the arrival of the full moon, fishing drops off
dramatically. As the moon begins to wane, fishing picks up again, with the
best fishing closer to the new moon and the fish being caught with shorter
leaders.
Water temperatures and thermoclines have not been
discussed although they are as important as any other factor in
swordfishing. Moreover the age of question of why do lightsticks work
still hasn’t been answered. More to the point. Do lightsticks attract
swordfish directly or do they attract baitfish, which in turn attract the
swordfish. Probably both, but don’t forget that if you happen to catch a
few swordfish from time to time and you are fishing during the daylight
hours, try fishing at night with lightsticks and you may just discover a
new fishery resource just like the ones discovered in Hawaii, Uruguay,
Reunion Island, and the Seychelles.
Reprinted from
World Fishing August 1996
