Seneca Lake this past summer has had an eerie quiet to it. The fishermen aren't around. I know - because over the past 12 years of professional guiding, Seneca Lake was one of my main haunts. And it's weird being on the lake and not seeing more than one or two boats out fishing. Fishing for lake trout - Seneca's bread and butter fish, has been brutal. The slowdown started during 2015 (if not earlier) with complaints via regulars about tough fishing from Watkins Glen up to Long Point. I didn't think much of it - we were still doing well up north out of Geneva. The past two derbies have featured some pretty darn tough fishing. Going three days at six hours a day for a total of two or three fish is brutal. Ten years ago it was a no-brainer catching lake trout out of Geneva or Sampson State Park. The lake seems to be getting tougher by the week. I would attribute the bad fishing to a perfect storm.
Here's what I think is going on over there. I chalk the tough fishing up to 3 main factors:
Number #1: Lampreys. Lamprey control is vital to having a cold water fishery in Seneca Lake (as well as Cayuga Lake and the Great Lakes.) If you have too many lampreys, you don't have trout. Due to some heavy rain, the lake's tributaries were not able to be treated as scheduled during June of 2014. I believe that treatment was done in the fall.
Don't forget the heavy rains we had last June that flooded Watkins Glen! That could have also impacted the lamprey abundance. The eel-like creatures now spawn in the deltas of the lake, not just the tribs.
Number #2: Lake Trout abundance or lack thereof. DEC Region 8 has cut back stocking on lake trout in Seneca Lake twice over the past 15 years if my memory is correct. This has been to compensate for larger numbers of wild fish being spawned out in the lake and less harvest by anglers. It was hoped that cutting back laker abundance would help young rainbows, browns and salmon to survive to adulthood, rather than get preyed upon by hungry lakers.
Netting Surveys in 2005 and 2008 showed 65% and 60% wild fish respectively. Stocking was reduced for a second time in the last 15 years in 2012 by 33%. (That to me was a mistake.) A 2013 netting assessment showed wild fish numbers had declined to 45%. So do the math - less wild fish plus a 33% stocking cut means a lot less fish!
Lake trout provide a very important buffer that actually helps the younger fish. Dan Bishop's theory (Master's theory I believe) was that in a lamprey infested lake, having 60% lake trout in the salmonid creels was the optimal percentage. Over 60% and the lakers start eating too many young salmonids. Less than 60% and lampreys take care of the young salmonids. As an aside, that's one reason why it's foolhardy for the Lake Ontario Stakeholders to want to cut back laker stocking much.
However the Diary Results are not neccessarily the best way to calculate lake trout abundance. As a diary keeper I am mainly targeting lakers during the late spring and summer. Our methods are usually very effective so our catches (and other jiggers) can skew the numbers - since we are not generally catching non-lakers. On top of that, you have newer issues like the widespread weedmats and waterfleas that keep trollers off the lake (or at least render them much more inefficient) during the summer. These trollers are the ones that would be catching the non-lakers. So even if the fishery were in balance, the numbers in the diaries would not indicate this to be the case.
Number #3: Algae Blooms. Seneca Lake has had some algae issues that have made for very poor visibility in the depths. That can make for very slow fishing.
Of course there are other concerns: I worry about excessive nutrient loading and salinity. But these water quality issues are generally monitored by Hobart. You'd think that decaying milfoil might use up oxygen in the depths. However, if these were issues, the whole lake would not be affected.
When lamprey numbers are high, non-lakers are low in population and then add in low laker numbers and you wind up with very high numbers of baitfish. That what happened to some extent around 1980. We had good rainbow numbers, but laker numbers were very low, so smelt numbers went way up. I realize that one some days anglers don't mark a lot of bait on Seneca Lake. But I had one day in particular this past summer when I saw more bait that I'd ever seen just about anywhere! Nearly anywhere I went - top to bottom. And that was from Lodi to Geneva. And on another day I saw the same thing from Watkins Glen north.
There's no need to panic on Seneca Lake. Region 8 Fisheries will be gillnetting the lake in 2017. They bumped up the assessment that was originally scheduled to take place in 2018. If laker numbers are very low (and I'm sure they will be) I would expect stocking increases to take place. Once that happens and lampreys are brought back under control, Seneca Lake will return to the powerhouse fishery that we all know it is. Until then, there's Cayuga Lake amongst others to fish (and learn if you haven't fished them before.)
Any errors above regarding stocking/lampreys et. al. are strictly my fault!