Suckers and Trout, an observation...

[cmkrachen]

Expanding on a reply from the fishing reports thread just to get more opinions and place the discussion in the proper place.

Disclaimer...I AM NOT SUGGESTING SUCKERS HURT TROUT POPULATIONS... However...my overall theory, less or no suckers, would equal larger trout.

This is one of my favorite subjects! I agree 100 percent with the above statements that "suckers don't hurt trout" i agree...i am not in anyway whatsoever suggesting suckers have a negative impact on trout. My logic and reasoning is simple and based in basic biology, ecosystems and food chains. Suckers eat the same exact food items that trout eat. FACT. Suckers BIO MASS is much greater than that of the trout based on numbers AND average size of suckers...and averaged size sucker is probably (based on last time i fished spring) around 17 inches. FACT trout eat SOME sucker eggs...remember, trout arent getting behind suckers spawning soley to eat eggs, they are often eating what the suckers stir up but digging redds. FACT trout to not sustain themselves for long periods of time on sucker eggs. FACT suckers also eat trout eggs. FACT trout (larger trout) will eat small suckers, which however grow at an extremely rapid rate.

To me it is quite simple, if there were NO suckers... ALL of the insect life consumed by suckers would now be consumed by trout and or other forage fish and crayfish. Trout would not suddenly starve because of a lack of sucker spawn to eat. the trout population would either increase, or the fish would gain overall larger average sizes.

I also agree that if there were a sort of slot limit on trout, IE you can take fish between 8-12 inches this may also increase size of trout, however in PA with the poor enforcement we already have on C&R streams, i dont think youd be successful implementing slot limits because too many guys would just take a limit and not care about the sizes...

Fun stuff and look forward to hearing responses...AGAIN just to be clear, before people chime in. IN NO WAY DO I THINK SUCKERS HARM THE TROUT POPULATIONS.

ALSO I REALIZE THEY HAVE LIVED TOGETHER IN STREAMS FOR YEARS. The point here is not whether suckers belong or not, merely, would we have bigger trout if they were not present.

AND IM NOT RETARDED I DO REALIZE HEALTHY POPULATIONS OF TROUT EXIST WITH SUCKERS AND SOME LARGE FISH ARE PRESENT IN STREAMS...

(im doing this just because i hate reading responses that are completely off base...i figured with caps people wouldnt miss the obvious, i realize some people read a post quickly and jump to conclusions)

 

[PennKev]

FACT. Suckers BIO MASS is much greater than that of the trout based on numbers AND average size of suckers...and averaged size sucker is probably (based on last time i fished spring) around 17 inches.

This is true but proves nothing. Different species, different habits, different requirments.

FACT suckers also eat trout eggs.

Maybe, but then again, almost every omnivorous fish will eat eggs if they are available. The real question is do suckers disturb and destroy viable eggs? A trout egg that is free from the redd is probably not viable and would not hatch anyway. On, the other hand I don't think suckers pose much threat to eggs buried in a redd. I've never seen or heard of suckers destroying the nest of any fish while feeding on the eggs. I don't believe this is typical sucker behavior.

FACT trout eat SOME sucker eggs...remember, trout arent getting behind suckers spawning soley to eat eggs, they are often eating what the suckers stir up but digging redds.

True, but this does nothing to hurt the size or number of trout.

FACT trout to not sustain themselves for long periods of time on sucker eggs.

True. The opposite is also true. Probably more so.

To me it is quite simple, if there were NO suckers... ALL of the insect life consumed by suckers would now be consumed by trout and or other forage fish and crayfish. Trout would not suddenly starve because of a lack of sucker spawn to eat. The trout population would either increase, or the fish would gain overall larger average sizes.

I think you are wrongly assuming that all or much of the forage consumed by suckers would be available to trout or even desired by trout. Trout and suckers have different feeding habits. Although some of their forage is they same, they are obtaining it differently. I don't think we'll see trout licking the slime off of a rock any time soon, nor will we see suckers rising to tricos every morning on Spring.

FACT trout (larger trout) will eat small suckers, which however grow at an extremely rapid rate.

I agree that trout eat suckers, but can you provide some data on sucker growth rates? I've never seen any. Also, are you sure that suckers don't suffer extremely high mortality as juveniles, thus we mostly see and catch fish that have outgrown predation? From my observation, they seem to really take a beating from herons.

...however in PA with the poor enforcement we already have on C&R streams,

We might have inadequate enforcement, but is poaching the exception or the rule? It's easy to blame harvest for the woes of our wild trout fisheries, but is it really the problem or just a convenient scapegoat?


Kev

 

[cmkrachen]

- "I've never seen or heard of suckers destroying the nest of any fish while feeding on the eggs. I don't believe this is typical sucker behavior."

Not saying they do.

- "True, but this does nothing to hurt the size or number of trout."

Read the post I repeatedly said suckers do NOT hurt size or number. Simply questioning if there were less suckers would the trout be bigger as a result.

- "True. The opposite is also true. Probably more so."

Did not anywhere suggest that suckers did sustain themselves on trout eggs (if that is what you were alluding to, this was unclear to me).

"I think you are wrongly assuming that all or much of the forage consumed by suckers would be available to trout or even desired by trout. Trout and suckers have different feeding habits. Although some of their forage is they same, they are obtaining it differently. I don't think we'll see trout licking the slime off of a rock any time soon, nor will we see suckers rising to tricos every morning on Spring"

This info PER PA's website on fish... "The adults eat aquatic invertebrates, insects and mollusks. They also consume some aquatic plant material." PENNKEV that says "some" aquatic (slime) suckers are not vegetarians, they stir up the bottom rooting out nymphs crayfish etc...brown trout do the same thing, i have seen this behavior personally, browns in spring creek especially often root around in water cress and elodea patches in order to consume cressbugs and other invertebrates.

THEY DONT SUCK SLIME OF OF ROCKS...so again, your perception that they eat different food is incorrect.



- "We might have inadequate enforcement, but is poaching the exception or the rule? It's easy to blame harvest for the woes of our wild trout fisheries, but is it really the problem or just a convenient scapegoat"

Harvest and poaching are two different animals, but both remove larger specimens from the stream. The guy catching a 20 inch trophy for his wall creates the same result as the guy poaching a 20 inch fish in a CR water. I am not suggesting whether either is the exception of the rule, merely stating that harvest enforcement on CR streams and trophy regs streams IS HIGHLY LACKING. Understandibly so, the state in the eyes of many has more important issues such as economy etc, that preclude large amounts of resources going to funding field officers for fish and game departments. Not to mention the vast mileage of PA waters.

Points well taken, but unfortunately you assume trout and suckers eat different things, they dont. trout may not feed on top, but they eat vast quantities of nymphs, as demonstrated by the large size of the average fish. Those fish dont gain caloric intake sucking slime, they get it by eating the same exact foods trout eat. If those pounds of calories were not in the bodies of the suckers, they would be in the stream and avaliable for the trout.

 

[cmkrachen]

Further - for those who love the sucker spawn argument as a major portion of trout feed, "The fish spawn from early May to early June" - PA bio website http://www.fish.state.pa.us/pafish/fishhtms/chap12.htm That quote is in reference to the white sucker. Redhorse suckers, another very common if not more common sucker, reach sizes of 25-30 inches. they tend to spawn in May and early June which many of you would label as prime time Dry fly water...admittedly suckers will begin spawning earlier, however they dont spawn December through February giving fish a winter boost...most of the literature i've reg suggests stream temps need to bump up, and most spawning occurs spring through early summer...water temps from the high 50s to low 70 are required for most redhorse spawning activity.

 

[salvelinusfontinalis]

I disagree.

Streams have a carrying capacity. I think if the suckers in a stream like spring creek were gone, it would just mean more trout but nothing of any greater size. Fish require more protein after about 14 inches to grow any bigger than they are. Bugs and nymphs just cant provide enough.

The suckers being gone would lead to more trout since they would be eating what the suckers "steal" from them. However, the trout would be eating themselves to get bigger rather than eating the suckers and themselves. Its a wash.
I think if anything. It would just lead to a few more trout.

Spring is a bad example given the massive amount of fish it already holds. More over, who is to say it is at its carrying capacity. We have no idea. Also given severe events, ie: floods, drought, heat, pollution or anything the population will fluctuate. I think spring as roughly 2000 trout per square mile (i might be wrong on this as it changes constantly), but who is going to notice 2200 trout per square mile as opposed to the latter? Now on infertile streams with brook trout, it might make a difference. Spring is just to fertile to use as an example.\

As far as the sucker spawn argument you pointed out.

Trout can survive in water between 33 - 75 degrees (depending on species and the high temp is debatable), but
grow most rapidly in water that is 50 to 65 degrees F and are less susceptible to parasites and diseases at these temperatures. These temps are right during the sucker spawn. Enough suckers and the more eggs the faster the trout will grow. Just a thought.

Just my take.

Which redhorse sucker? Some redhorse suckers are now candidates for threatened or endangered species status.

 

[PennKev]

Points well taken, but unfortunately you assume trout and suckers eat different things, they dont

No I didn't I used the example of slime on rocks vs. surface feeding to point out that the fish behave differently and take advantage of different feeding opportunities. Suckers and trout have very different body structures and habits for feeding. Just because both will eat mayfly nymphs does not mean they are in direct competition since they are feeding in a completely different manner. AGAIN, the bugs that a sucker eats may not be available to a trout and vice versa since either fish has different habits. You are asuming that forage, specifically insects, that a sucker eats would be caught and eaten by a trout if not for the sucker. I firmly believe this is falacy.
As for trout foraging through weeds, this is not the same behavior as suckers grazing on whatever happens to be laying on the bottom (including insects). However, I've never seen a trout feeding off the mixture of detritus and algae growing on the bottom surfaces of a stream in the same manner as a sucker. This material is super abundant in most streams and offers a potentially huge source of food for suckers that trout may not be able to take advantage of at all. Suckers are built to consume this material and capture anything that might be living in it. Trout are not.

We are not comparing two species such as browns and brookies which we know are in direct competition with each other. Those are fish with similiar physical rquirements, similiar body structure, and similiar habits.

To summarize my stance: Suckers and trout fill different niches and the fact that one species grows larger and is more numerous is not evidence that they are directly supressing the other.

Also, I think you are talking out of both sides of your mouth. You list so called "FACTS" that certainly imply negative ffects of a sucker population then you keep saying that you don't think suckers hurt trout populations. Guess what? Supressing biomass either by a lower number of trout or lower average size is a negative effect!!!! If you believe that suckers do either of those things, then you cannot say that you don't think and abundance of suckers hurt the trout populations!

Your words from the other thread:

i used to routenly bank suckers...they eat the same fish as trout and the bio mass of them is enormous. if there were no suckers at all, there would be much larger trout...the food the suckers eat would in turn be eaten by the trout...i'd bet 2 million on that...

This is deplorable activity as far as I am concerned since there is no sound evidence that you are helping another species. The only thing that would seem certain is that you are reducing the competition between suckers!
If suckers don't hurt trout poplations, as you say, why bother killing them?

It seems you are trying to play both sides of the fence so that when the discussion is done you can still claim you were right all along.


Kev

 

[troutbert]

cmkrachen wrote:

Disclaimer...I AM NOT SUGGESTING SUCKERS HURT TROUT POPULATIONS... However...my overall theory, less or no suckers, would equal larger trout.

To me it is quite simple, if there were NO suckers... ALL of the insect life consumed by suckers would now be consumed by trout and or other forage fish and crayfish. Trout would not suddenly starve because of a lack of sucker spawn to eat. the trout population would either increase, or the fish would gain overall larger average sizes.

To say that the trout population would increase or that the fish would gain overall larger sizes if there were no suckers means that you are saying the suckers hurt trout populations. There's no way around that.

There's no reason to hedge. Just give your opinion and reasons why and other people will give theirs. You believe that suckers hurt the trout population. There's no reason to be ashamed of that. You may actually be correct.

I don't know if they do or not. It seems logical to me that since suckers do eat many of the same foods, and are often found in the same pools, that they are competing with trout for space and food, and that eliminating them would boost the trout population. But I don't know if that's really true or not.

What I'd like to know is what factors cause high or low populations of suckers in streams. Some streams have lots of them, other streams have few to none.

 

[salvelinusfontinalis]

Kev,

Suckers and trout have very different body structures and habits for feeding. Just because both will eat mayfly nymphs does not mean they are in direct competition since they are feeding in a completely different manner.

I think you make a very good point here.

You are asuming that forage, specifically insects, that a sucker eats would be caught and eaten by a trout if not for the sucker.

You also make a good point here.

I might have to re-think what I wrote and side with you on this.

 

[Chaz]

FACT, there is no stream that I have fished that has both suckers and trout that most of the invertebrate life isn't thriving. FACT, trout eat a lot of suckers, sucker eggs and thing stirred up by suckers. FACT, where they exist in streams together, you always have the most diverse populations of aquatic life and usually very high populations of trout. FACT, Brown trout kill more native fishes and insects because there is nothing to keep brown trout in check, they are the apex predator in our streams. Since they are invasive species we should remove all the brown trout from our streams and let suckers rule, they are native to our streams.
The last statement is made to make a point and should not be construed to be a call for removal of brown trout from our streams.

 

[troutslammer]

they may compete for the same food but who wins 90% of the time , if there is a hungry trout in a pool then normally 9-10 times they will get the meal before the sucker so suckers don't hurt the trout diet at all

 

[rrt]

Not really sure of all the biological facts regarding suckers and trout, but I know that some of the very largest trout I've ever seen and caught have been living in the midst of schools of suckers. I don't know if that means anything, just an observation.

 

[Acristickid]

FACT: Work is for Suckers

 

[salmonoid]

rrt wrote:
Not really sure of all the biological facts regarding suckers and trout, but I know that some of the very largest trout I've ever seen and caught have been living in the midst of schools of suckers. I don't know if that means anything, just an observation.

I'm loathe to draw any sort of conclusions from sample sizes of one, but I have similar observations. The largest wild brown trout I've ever taken on a fly rod shares a beautiful pool with about two dozen suckers. What I cannot say or prove is that if the sucker population in that pool were zero, that there were be two large brown trout living there... Nor can I tell you how many small brown trout or small suckers the large brown trout ate to get as big as he did. I do know he did not grow to that size by eating insects for the last few years...

 

[cmkrachen]

Interesting points, like i said it was a food for thought. And i hedge myself because i dont KNOW, although i have an idea/theory, noone really knows. Fact I dont find it "deplorable" at all to feed a raccoon or eagle or pack of ravenous crayfish once in awhile...

Also, I've been fortunate enough to fish ALOT of water outside of the state where there is not a stocking truck to be found, or a pod of suckers...and there the fishing is quite nice and its hard to catch small fish, just an observation...

 

[pcray1231]

To me it is quite simple, if there were NO suckers... ALL of the insect life consumed by suckers would now be consumed by trout and or other forage fish and crayfish.

Here is the failure of your analysis. ALL insect life is not consumed by fish in general, not even close. If it were, aquatic insects would go extinct in short order. I certainly have no factual data, but I would venture to guess that the total % of aquatic insects that are consumed by trout and suckers combined is in the neighborhood of 5%.

So if that were true, then without suckers, it might drop to 2%. Does that greatly effect the number of insects available to trout? I doubt it.

The real question is holding water. Trout compete for holding water/feeding lies, and the biggest trout get the best feeding lies; the areas where more food flows by in a given time frame. I don't think that the # of suckers in the stream greatly effect how much food flows by those good feeding lies. The question is whether they compete for the same feeding lies.

If yes, then the larger more agressive fish win, and the two populations do indeed effect one another. Since suckers are larger, it is likely trout are the losing end of that more often than not. Yes, suckers would hold the average size of trout down some.

If no, then the two populations don't effect each other greatly.

My gut feeling says mostly no, though there are probably situations where there's an effect.

 

[cmkrachen]

PCRAY i realize that not all insects are consumed by anything, I assumed that people would be intelligent to figure that out. I erred in assuming that obvious things were well obvious... im not sure if that is a failure in my analysis or a failure of you inferring that im not a 4 year old and understand that insects would go extinct if something ate ALL of them...c'mon man really?

 

[cmkrachen]

additionally, pennkev i like you're avatar, what the photo is likely showin is the sucker moving rocks....they often turn and roll rocks with their inferior mouths in order to find insects...they dont suck slime like the algae eaters in your aquarium...sorry man...nice try though i hope you didnt spend 2 much time looking for that picture

 

[salvelinusfontinalis]

Young suckers eat zooplankton and algae. They are important forage fish for larger game fishes. The adults eat aquatic invertebrates, insects and mollusks. They also consume some aquatic plant material.

Your both right 🙂

 

[troutbert]

Does "Here is the failure of your analysis" mean the same thing as "In my humble opinion?"

Just asking. 🙂

 

[gulfgreyhound]

The niche is the key to the question.imo GG