Posted on July 31 2023
It's Sunday afternoon and I'm home waiting for cocktail hour with my wife. There was a dearth of questions this week so the page will be spent discussing the long term effects of the FFMP.
The FFMP (Flexible Flow Management Plan) is the best flow program I've seen during my 35 years fishing the Delaware River System. The increased flows have resulted in a major increase in both the fish carrying capacity of the WB and the BR and the number of drift boats floating them. Keeping the water temp below 75 at Lordville provides a large thermal refuge for the down river fish which in turn increases the number of fish all the way down to Callicoon during the "big bug hatches". Elimination of the dewatering of large portions of the stream bed in the upper WB caused by the former low flows has resulted in a major increase in caddis hatches in the "Sulfur Zone". These are the basic plusses that I have observed.
As with most everything in life - if there are plusses there are also minuses. I've given some thought to things I've observed over the past few years that I believe can be considered negatives when talking about the FFMP releases. (Here's where he goes on a rant about the number of drift boats). No, drift boat fishing has evolved with an acceptable pattern of behavior for both the drifters and waders that most abide by and can live with.
The negative I am talking about is the impact the additional releases have had on the insect life in the upper WB and the fish that reside therein. I have no formal education in entomology or marine biology and would welcome one educated in either field to set me straight, but here are my thoughts and observations.
1 - Tailwaters are known for prolific hatches of a limited number of different bugs (think olives and sulfurs on the Delaware).
2- When I started fishing the Delaware and for many years thereafter there was a full compliment of may fly hatches at least up to Oquaga with many hatching up to Cold Springs Brook.
3- As flows have increased (each lowering the water temperature a further distance down river) the upriver hatches of the "non- tailwater bugs" have decreased and in some cases virtually disappeared.
4- The hatching of Tricos, Green Drakes, and Ephorons (all warm water loving flies) have always been limited to the lower reaches of both the UEB and the WB and the BR. With the increased flow of cold release water, other species have also disappeared from the colder water in the upper WB. I use to see good hatches of Gray Foxes, March Browns and Isos well above Deposit. The Hendricksons which are both hardy and prolific have continued to hatch up river but the hatch starts later and runs later in Deposit than it use to (cold water slows the maturation of the nymphs?). Which brings me to my comment about Green Drakes hatching at the Red Barn (aka pasture pool), Every summer fishermen see a few green drakes on the water there. Their maturation is a good two months behind their freestone river friends and I think they are going to find slim pickings when looking for a mate.
So, assuming that my observations are accurate and meaningful what does this mean for the river system?
1 - It has been my observation that fish are growing slower in the upper WB of the Delaware in recent years. Is this because the cold water slows their metabolism or because, with the absence of the aforementioned bugs, there's just not enough food for them to grow as fast, or perhaps a combination of both?
2 - There is now, a seemingly ever increasing gap in the fly hatching activity in the upper WB fishery after the Hendricksons and caddis and before the summer sulfurs (Dortheas). The Invaria (spring sulfurs), long a gap filler, seem to be less and less numerous up river every year, quite likely they are not a true tail water sulfur and are also negatively affected by the lower water temps.
It's not my intention here to champion either bigger or smaller releases. I just want to show that there are consequences to whatever action is taken (some of which evolve over a period of time. come as a surprise and are unintended). Would welcome observations from other fishermen as well as input of a scientific nature from either entomologists or marine biologists.