The great Hendrickson mystery
Here we are, after a long winter of tying flies, checking equipment, talking about it with friends, and generally chaffing at the bit. It is finally Hendrickson time in the Catskill’s. At least according to the calendar, hatching charts and previous years notes, it is.
This hatch is eagerly awaited by all who ply Catskill Rivers with a fly rod. It’s the third week of April; fly boxes are full, rods and waders are packed, and we’re off to find Hendrickson. At least we’re supposed to be. A check of flows in most Catskill rivers on April 21 shows that the Beaverkill, West Branch and the East Branch below Pepacton are too high and cold to fish. The local websites confirm that. But the East Branch above the reservoir has come down and is fishable—so there is hope after all.
We arrive at about 1:30 p.m., park by the reach between Margaretville and the reservoir, and make our way to the river. It has finally warmed up, and I have a good feeling there will be flies today, as I tell my friend Rod. Hendricksons (females) and red quills (males) generally hatch about 2 p.m. and continue until 5 p.m. or so. On the bank, we join rods and thread line through the guides, always with one eye on the river, ever vigilant for the first duns. Rod goes up river; I go down, to a run that opens to a nice quiet pool. I’m thinking that since the water is cold, if the flies show, the fish will move into the slower areas to feed, rather than fight the current. And I watch.
About 2:30, I see a little gray sailboat on the water, and it lifts off, beginning its flight to the safety of the bank vegetation. Hendrickson 2017 has begun! I’m eager now, my anticipation is high. The rod hasn’t bent with the throb of a good trout since October. Now I watch, and wait. By 3, that hatch has intensified, with a good number of duns, some blue quills and a lot of little caddis flitting about over the river. No rises, yet though. Should I be concerned?
Then it is 3:30; one rise across the river. Then another, in the same spot. Hope! Now it’s 3:45; I hear a splash up river in the heavy water, but there is no lasting ring of that rise. Now it’s 4, and the flies continue, but are beginning to slow. Rod has moved down and is across from me. I yell: “They’re not going to rise today!”
So it’s back to the car and the long ride home to ponder and discuss the day. At least there were flies—a good sign that the season has begun. When a hatch lasts several hours and there is no surface feeding activity, particularly early in the season, anglers become perplexed and discouraged. After all, there were plenty of flies, and the flow was OK. So anglers become confused, have no answers and leave the river, mumbling and shaking their heads. Tonight there will be phone calls to fellow anglers, telling of a large hatch with no rising trout. Discussions will ensue about why it was the way it was. There might even be a few expletives.
The question is: why are large hatches of mayflies, in this case, Hendricksons, ignored by trout?
All salmonid fishes are cold blooded creatures. Research has documented that brown trout, our most abundant species, feed most actively when water temperatures are between 55 and 60°F. Hendricksons begin to hatch when water temps approach 50°F. See the problem here? I’ve observed the lack of surface-feeding activity so often during the Hendrickson hatch that I would call it common in spring. Couple high flow with cold water temperatures, and conditions are perfect for the lack of rises. The difference between 50 and 55° is huge when it comes to trout feeding. And all anglers can do is wait until water temperatures rise, with hope that the Hendrickson hatch is not over.