Conditions have to be perfect for a full-blown hatch, thus they have a reputation as elusive because the variables often don’t line up. “Worm hatches are a local phenomenon and quite variable,” says Alan Caolo, author of Sight-Fishing for Striped Bass. “Which explains why so many hypotheses are correct and at the same time contradictory.”
Still, there are some constants that, combined with local knowledge, enable predicting the hatch in particular areas.
There’s evidence that cinder-worm hatches are brought on by moon phase. “The occurrence of swarming is dependent more on lunar cycle than any other factor,” notes Lillie. “Each run begins near the time of the full moon, increases to a maximum during successive nights, sinks to a low point about the time of the third quarter, and then again rises and falls to extinction shortly after the new moon.”
Caolo argues that hatches are determined by temperature in the sediment and the water column. New and full moons increase tidal highs and lows. Cinder-worm emergence might be stimulated by the sun warming bottom sediments during lower-than-average tides. Yet it still takes a certain temperature in the water column as well for the spawn to go off. “If you have a day with high sun and low water because of the full-moon phase, [the hatch] may go two days strong, then if it gets cold and gray, it will turn off right away,” says Caolo. “Just about everything that is cold-blooded is really a function of temperature.”
Two studies in the journal Marine Biology confirm Caolo’s theory. In 1988, O.F. Müller exposed Nereis worms to different temperatures and found spawning was induced by raising the temperature. In 1987, Heinrich Frey and Rudolf Leuckart conducted a similar experiment. Spawning was induced by raising temperatures around the time of the new moon. Lunar periodicity was illustrated under natural temperature programs, but it also demonstrated that an abrupt increase in temperature caused swarming to occur at different times of the lunar cycle.
You probably won’t find a hatch under windy conditions. “When a female appears, she’s soon surrounded by several males, which swim rapidly in narrow circles around her on the surface,” notes Lillie. Worms indeed might emerge from the mud during windy conditions, but they likely can’t perform such mating behavior if there are waves tossing them.
Fishing a hatch is difficult without moving water. You might see stripers slurping worms all over the place, yet because the amount of bait is extraordinary, getting your offering noticed isn’t easy. In such situations, fish will cruise to the worms. This means you have to anticipate their movement.
It gets easier with current. “Worms are fairly immobile in the face of even moderate flow,” notes Martha’s Vineyard guide Tom Rapone. “Stripers line up at feeding stations to take advantage of the easy meal sweeping by. Stripers holding in a current seem more likely to single out individual targets.”
Match the Hatch
“Fishing the hatch on the days leading up to the peak or in the days where it begins to wane can be better, as there are fewer real worms,” notes Dixon. On such nonpeak days, matching the hatch is a good bet. When the hatch is in full swing and there are thousands of worms in a small area, a different approach is required. “There’s often so much bait in the water, just throwing something bigger will induce strikes,” says Blinken. Caolo likes soft plastics: “Four-inch pink Slug-Gos are about as deadly as you can get.”
Caolo likes a floating fly line and a 7- or 8-weight fly rod. He recommends keeping the fly near the surface, making small erratic strips and then allowing it to drop for a few seconds. Dixon recommends dead-drifting the fly with a floating line while mending it, keeping just enough tension to feel the strike. With spin gear, slow it down. Fish do not put out more energy than they need to in acquiring prey.