Understand how moonlight and moon phases affect sword fishing
To better understand why swordfish concentrate their feeding habits at certain depths on a given night or why biting is better during different times of the month, it is necessary to better understand how the effects of moonlight influence the fish. sword.
Before you can understand how swordfish are affected by moonlight, you need to understand the moon and its phases. The moon revolves around the earth in 27 days. The first phase of the moon at the beginning of its new revolution is what we call the “New Moon”. The new moon is when the face of the moon is in the shadow of the earth, which causes the moon to not reflect light and appear dark to us. One week after “new moon,” the moon will be at its first quarter, which means that a quarter of the moon’s total surface area is reflecting light back toward Earth. Since we only see 50% of the moon’s surface, when the moon is in its first quarter, many of us call it a half moon, since half of the moon’s face reflects light. One week after the first quarter the moon will be full, and the entire face of the moon that is visible to us will be reflecting light. One week after the Full Moon and again the moon will appear as a half moon as it will be in its last quarter. One week after the last quarter, the moon will have completed its lunar cycle and will be a “New Moon” again.
Now, if we look back at our previous swordfish trips and our catch statistics, we would see patterns for some nights where all bites were at depths greater than 200′. And we would also see a pattern for a couple of nights when all the bites were at depths less than 100′. These changes are a direct effect of the amounts of moonlight that was present during these patterns. We know that swordfish is a predatory species that feeds on concentrations of squid and mackerel, which are diurnal species, meaning that during the bright hours of the day they stay in the deepest, darkest depths of the ocean and as it recedes daylight and night falls, they ascend to the shallowest depths. Now, moonlight plays a role in where concentrations of the bait will congregate. For example, during a full moon, since much of the moonlight shines through the surface of the oceans, bright moonlight will cause the bait to stay deeper in the water column. Conversely, during a new moon with virtually no moonlight breaking the surface of the oceans, the bait will congregate in shallower depths closer to the surface.
Of course, we should always have a bait in both the deepest and shallowest part of the water column no matter what phase of the moon we are in, just in case there is a swordfish wandering around. Although, the brightness of the moon is a very good indicator of how deep most swordfish bites will be found. During nights when the moon is full and bright, most baits must be fished deeper in the water column.