How could a sunfish beat a lake trout?

A fishy disaster is happening at Lake Sunapee.... again,

The one before (the famous one) were lake trout devouring, interbreeding with, and killing the sunapee trout. Now the salmon and lake trout are in trouble from the lowly rock bass.

According to this article. http://www.sunjournal.com/node/647502 some unusual event has tipped the Balance on Lake Sunapee making rock bass successful while the top salmonoids are in decline. This problem doesn't seem to occur in similar lakes.

No one seems sure what that is. What kind of disturbance could tip the balance in the sunfish's favor?

Given the history of Lake Sunapee I wonder if the solution would be another fish that outcompetes the rock bass.

I wouldn't have thought of those fish being in direct competition. Is the lake getting warmer/weedier/more eutrophic/all of the above?

I wouldn't have thought of those fish being in direct competition. Is the lake getting warmer/weedier/more eutrophic/all of the above?

Predation on fry & out competing juvenile fish. Rock bass are great fun to catch while fishing. Their aggressive feeders (atleast when you drop a dace near one).

Just thinking out loud here:

The anglers' logic "There used to be many trout here; now there are few trout and many rock bass; therefore, rock bass are causing the decline in trout" seems obvious enough, but could be totally false. A very similar logic, believed by many hunters in my area, has it that "There used to be many quail in this field; now there are few quail and many turkeys; therefore, turkeys are causing the decline in quail." This is nonsense. Quail leave a given field as it undergoes ecological succession and the plant community and physical structure of the habitat changes to something more suitable for turkeys. My intuition is that something similar is happening in this lake- an underlying ecological change that favors a fish (rock bass) which loves structure, feeds on nekton and clinging inverts, and has a higher tolerance for warmth, turbidity, nutrient loading, etc. than do trout.

I admit I don't know much about the ecology of northern lakes, but it doesn't sound likely to me that a rock bass boom would by itself have much impact on trout populations. Rock bass are structure-loving ambush predators; I think of trout as more open-water or benthic fish. Wouldn't they be using different enough resources that competition would be slight? And of course trout are at least as piscivorous as rock bass are; rock bass may eat baby trout that wander into their habitat, but trout are doubtless just as apt to eat baby rock bass.

I've had open lake trout and rainbow trouts up and their stomaches were full of baby sunfish/rock bass. However the niches of both fish do not fit each other as Newt has explained above. Lake trout are piscivorous, much more than rainbows and brookies, so they shouldn't have any problems to prey on young rock bass.

My guess is there are other factors that goes unnoticed or just don't mentioned.

I've had open lake trout and rainbow trouts up and their stomaches were full of baby sunfish/rock bass. However the niches of both fish do not fit each other as Newt has explained above. Lake trout are piscivorous, much more than rainbows and brookies, so they shouldn't have any problems to prey on young rock bass.

Is the different habitats why some studies I read showed that lake trout and landlocked salmon have very limited diets. (mostly Smelt, aquatic insects, and perch, other fish making up less than ten percent if i remember right, been years since I read them). Maybe if rockbass moved into the smelts spawning streams they could have upset the balance.

I'm not sure that rock bass can put a dent on smelt populations. Sure rock bass can eat small fishes but I don't think the small fishes, especially larger smelts are main diet for rock bass.

Honesty I think predatory fish in different lakes have different diet from similar species from another lake. Rainbow trout of Grindstone Lake, prefer YOY bluegills as a part of diet. One rainbow trout has 50 YOY bluegills in his stomache.