Does Forage Base Matter?
Slamr
Posted 12/7/2005 4:43 PM (#167977)
Subject: Does Forage Base Matter?





Posts: 7036


Location: Northwest Chicago Burbs
Just wondering......

Seems as though lakes with large populations of fish such as Cisco, Shad, and/or Trout appear to have fat, large fish, and some waters with forage bases made up of perch, panfish, and suckers dont. Or am I over generalizing?
Guest
Posted 12/8/2005 7:13 AM (#168057 - in reply to #167977)
Subject: RE: Does Forage Base Matter?


Overgeneralizing.
Dave N
Posted 12/8/2005 10:25 AM (#168077 - in reply to #167977)
Subject: RE: Does Forage Base Matter?




Posts: 178


Slamr - 12/7/2005 4:43 PM

Just wondering......

Seems as though lakes with large populations of fish such as Cisco, Shad, and/or Trout appear to have fat, large fish, and some waters with forage bases made up of perch, panfish, and suckers dont. Or am I over generalizing?


Probably over-generalizing Slamr, but assuming you brought this up mostly to stimulate discussion, there are some interesting aspects to your question. One thing we know from direct experiments with esocids at the University of Missouri-Columbia and elsewhere is that they exhibit a strong preference for prey species with cylindrical or fusiform shape and soft fin rays. That puts suckers, ciscoes, and other esocids at the top of the musky's menu of preferred food items. It puts bluegills and crappies at the bottom. Perch are also near the top of the list because of their fusiform shape and their behavior, despite their spiny fin rays -- perhaps because they are small enough that the spines are usually a non-issue. Walleyes are fusiform, but there must be something about their behavior (low-light activity periods), average size, spiny fin rays and possibly other factors that renders them far less vulnerable than perch to capture by muskies. Yellow perch (along with suckers) are a mainstay in the diet of muskellunge in many of our lakes. We rarely see walleyes in musky guts, but we often see walleyes with scars that suggest a large esocid has tried but failed to kill and eat it. Such scarring is most prevalent in lakes known to have exceptionally high muskellunge density (1.0 per acre and greater). NOTE: You're getting the observations and speculations of an old field biologist here -- some but not LOTS of published documentation, so please take it as offered, with a grain of salt.

Wherever muskies must make a living by eating mostly bluegills or bass, they do not grow well at all, regardless of how many bluegills and bass may be in the lake. Natural mortality of muskellunge can be high in such situations; and few if any fish will ever attain trophy size. Beyond that, it is difficult to generalize about the sole effect of prey species composition on ultimate size attainment of muskellunge. Many waters without pelagic (open-water), soft-rayed prey (ciscoes, smelt, shad) -- like the Chippewa Flowage and Butternut Lake -- have produced monster muskies that grew to trophy size by eating mostly suckers, perch, bullheads, and other esocids. If those prey are available in sufficient quantity and the muskellunge are not harvested or accidentally killed by anglers or tribal spearers, then the muskies have an opportunity to attain trophy size. Moderate Growth Rate + Longevity = Trophy Fish.

It is interesting that anglers (myself included) sometimes get the impression that there are more trophy muskies in lakes that contain pelagic prey like ciscoes (north) or shad (south). The temptation then is to speculate that it's those pelagic prey species that are responsible for making muskies grow faster and get bigger in those lakes. But what if the real reason is RELATED to the type of prey, but INDIRECTLY so? WHAT IF the availability of pelagic prey simply puts muskies into open-water habitats where their vulnerability to angling is less than in waters with mostly littoral (near-shore) prey, thereby decreasing their probability of capture by anglers pounding the weedbeds, and thus increasing their longevity? Might this also be why we sometimes see huge muskies in small, little-known lakes that receive only light musky fishing pressure by anglers skilled in live release methods?

In the North, we have lakes that continue to produce some monster muskies, like Lac Courte Oreilles, where musky growth rate has been average at best, despite the availability of pelagic ciscoes as prey. But given the opportunity, LCO muskies have attained trophy size (mid 50-inch range), and they usually are in beautiful condition (very plump for their length). The Chippewa Flowage produces monster muskies that have never seen a cisco. In the South, we have lakes where muskies grow FAST (I saw some females hit 42" after only 5 years) eating mostly pelagic gizzard shad (Pomme de Terre and Hazel Creek lakes in Missouri), yet few fish there are reaching sizes of 50 inches and larger, quite possibly because Faster Growth Rate in southern waters + Shorter Natural Life Span in southern waters = Fewer 50" Fish. Applying Dr. John Casselman's philosophy, a "trophy" musky in those southern waters may well be regarded as a fish somewhere in the 45- to 50-inch range. (I know a few make it to 50" and above, so no hate mail from my homies back in Missouri, please!)

I guess this is my long-winded way of expressing my opinion that the development of a trophy muskellunge fishery is a complex interaction of many factors, including overall abundance of SOME TYPE of preferred prey. But there are various routes to getting big. WE can do it by eating french fries at fast food restaurants or ice cream at home. We can do it over 15 years or we can do it over 30. Either way, the results are the same if we don't die first! So it goes with muskies...

Dave Neuswanger
Fisheries Supervisor, Upper Chippewa Basin
Wisconsin DNR, Hayward

Edited by Dave N 12/8/2005 1:38 PM
Slamr
Posted 12/8/2005 1:52 PM (#168109 - in reply to #167977)
Subject: RE: Does Forage Base Matter?





Posts: 7036


Location: Northwest Chicago Burbs
Thanks for the response Dave!
Bytor
Posted 12/8/2005 7:53 PM (#168153 - in reply to #167977)
Subject: RE: Does Forage Base Matter?





Location: The Yahara Chain
Thanks for sharing that Dave, great info.
firstsixfeet
Posted 12/11/2005 4:30 PM (#168409 - in reply to #167977)
Subject: RE: Does Forage Base Matter?




Posts: 2361


Curious as to why the musky in the bass bluegill lakes have early mortality? Poor wintering condition? Poor prey capture conditions in the lakes that favor high populations of those two species, ie weedy?. Or choking?
Dave N
Posted 12/11/2005 5:53 PM (#168415 - in reply to #168409)
Subject: RE: Does Forage Base Matter?




Posts: 178


firstsixfeet - 12/11/2005 4:30 PM

Curious as to why the musky in the bass bluegill lakes have early mortality? Poor wintering condition? Poor prey capture conditions in the lakes that favor high populations of those two species, ie weedy?. Or choking?


FSF, I'm not sure. The actual mechanism for high mortality rate has not been determined in these situations. But if I were to guess, I'd say that muskies in these lakes have bioenergetics working against them. Procuring a meal requires too much energy when the only available prey are both physically and behaviorally sub-optimal. Your speculation about poor winter condition is not unreasonable. I doubt that weeds or choking are significant problems, but I cannot support that statement with any hard facts. Whatever the mechanism, musky populations in such lakes exhibit high natural mortality rates, and individual muskellunge rarely get big.

Dave Neuswanger
Fisheries Team Leader, Upper Chippewa Basin
Wisconsin DNR, Hayward