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Affects on Simcoe from gobys


cisco

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Looking back I do wonder whether and how the gobys have affected our fisheries since they scrounge around on bottom slowly and get easily eaten by even whitefish which have apparently started moving shallow to feed on them.  Sure they must eat tons of eggs/fry from bottom egging native fish (lakers is my biggest worry) but perch egg the weeds and so far I haven't personally noticed a drop in them.  Pike seem to be exploding so are they profiting from gobys also? Maybe whitefish spawn too deep to allow easy access by goby? Possibly whitefish have shot up since what normally eats it's eggs/fry are getting eaten by goby? 

Starting to think that deep or weed spawners are least hit by them while loving more food due to them.

Oh and of course it isn't acceptable to allow any exotic into an ecosystem so don't anyone get weird over this discussion, ok? The smelt pop'n seems almost gone (an exotic) and herring/cisco haven't taken so, why ???

It does seem the nutrients in the water column have been moved more to the bottom due to filtering by mussels and the advent of gobys and the attendant other species which focus mainly on bottom including whitefish.

As well the zebra mussels which when young are best referred to as 'popcorn shrimp' since their shell is so thin/soft that all fish have adapted to eat them everywhere including off docks and spots wherever the mussels are which is about everywhere shallow and even quite deep. So are the gobies also somewhat controlling the mussels now?

Thoughts?    

 
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As i have read in their native range gobies feed on zebra a quagga mussels, http://www.invadingspecies.com/round-goby/

" Benefit(s): The only benefit attributed to the round goby is that it is a voracious consumer of another significant Great Lakes invader, the zebra mussel (Dreissena polymorpha).  In one laboratory study (Ghedotti, et al,1995), round gobies of average (80 - 110 mm) length were able to consume zebra mussels 100 - 120mm in size and ate an average of 36 zebra mussels per day.  Gobies also seemed to show a significant preference for zebra mussels over native clams and snails when presented with varying distributions of clumped and unclumped prey over different substrates. However, because gobies do not have a swim bladder and are negatively buoyant, prey attached to an aquarium wall just 20cm off the bottom appeared safe from round gobies. "  

   http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Neogobius_melanostomus.html

Fish eat fish? I am guessing big perch, crappie, or whatever will eat smaller gobies?

http://www.biokids.umich.edu/critters/Coregonus_clupeaformis/

Evidently whitefish spawn shallow? Not real sure what would be to deep for a gobie?

I have caught carp on tubes fishing for bass, just image how many fish eggs a 20+ pound carp can suck in? but they start off small to, and may be food for other species?

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Good info.. Ya with whitefish spawning not too deep maybe the eggs get into stone/rocks where they are harder for gobys to access. I think with lakers their fry go deep asap to prevent blindness. Yet they are not reproducing from what I hear/see caught with only larger fish being caught. I have to think gobys may be involved buy again, opinions are good to learn from here.

Re carp I know they love weeds/weed roots and that's why wild rice beds have been destroyed so many places. Many places in Simcoe don't have weeds so maybe the perch are also controlled by the carp. 

Edited by cisco
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Lake trout reproduction in Simcoe is horrible.  I wouldn't be worried about the gobies, I'd be worried about the lack of prime spawning habitat for those fish.   We're already seeing a huge decline of lakers in Simcoe, if the MNR doesn't start their stocking program back up and soon, that fishery is done.  Way to much silt and stuff over the spawning beds, due to farm runoff, etc. 

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Hard to say what amount and impact of the amount of 'runoff/silt' is on lakers. As long as a fertilized egg gets oxygen should be good to go. To have all midlake spawning shoals covered by suffocating silt seems a bit far fetched. Some should still be producing lakers. Don't see that though. However a new species such as goby eating small stuff on shoals is something more feasible IMHO. That's why some have been pushing MNHR to properly investigate rather than a tagging study which does not address the spawning habitat issue whatsoever. Perhaps even Goby traps set at spawning shoals can restore spawning success to an acceptable level if this is the case.   

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The 1 thing I've noticed it's harder to find that green color clear water.

Threw the 90's and until gobies effect showed up you could fish any area and find this water.

The last 5-6 years of tournament fishing I would drive the whole lake looking for water color then start my practice.

Even my perchn I prefer greenish color water and it gets harder and harder to find. Also makes catch results variable.

Might be why people complain about know big perch.

  

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On 6/14/2020 at 7:14 PM, cisco said:

Hard to say what amount and impact of the amount of 'runoff/silt' is on lakers. As long as a fertilized egg gets oxygen should be good to go. To have all midlake spawning shoals covered by suffocating silt seems a bit far fetched. Some should still be producing lakers. Don't see that though. However a new species such as goby eating small stuff on shoals is something more feasible IMHO. That's why some have been pushing MNHR to properly investigate rather than a tagging study which does not address the spawning habitat issue whatsoever. Perhaps even Goby traps set at spawning shoals can restore spawning success to an acceptable level if this is the case.   

The reports I've read from the MNR about prime spawning water on that lake aren't good.   Look at the lakers caught through the ice this year, mostly all big fish, low numbers, not many fish in the 3-6lb range.   That lake cannot sustain a natural population of lakers in it's current state with the amount of fishing pressure it gets.   MNR better get their act together.  

Edited by BillM
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Invasive species like the Round Goby are like a double edge sword. On a positive side, their abundance obviously provides what seems like an endless food source for bass, pike, perch whitefish etc. But their predation on the eggs and nests of these same species is a negative but I think it will be years before we understand the true impact that an invasive species like the Round Goby will have on a body water like Lake Simcoe. In the meantime it does appear that the Smallies are getting fatter & heavier...

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7 hours ago, BillM said:

The reports I've read from the MNR about prime spawning water on that lake aren't good.   Look at the lakers caught through the ice this year, mostly all big fish, low numbers, not many fish in the 3-6lb range.   That lake cannot sustain a natural population of lakers in it's current state with the amount of fishing pressure it gets.   MNR better get their act together.  

I agree with you Bill BUT what I am suggesting is that the dramatic end of seeing small lakers may be directly related to the onset of ,say, gobies. We would be catching at least a few small lakers if it was a spawning bed issue since IMO there is no possible way that 'suddenly' all laker spawning habitat got covered in silt to the point of zero natural reproduction. Some small vestiges of adequate spawning habitat has to be in the lake somewhere to produce some small lakers. But none are caught from what I have heard, read or seen. As for over fishing being the issue that cannot be logically asserted since there are lakers there of spawning age so again, we should still be seeing some small lakers from them. The tap got turned off and better research is needed to develop and to then explore  hypotheses. Tagging studies are not right for this application to determine what is preventing any natural reproduction. IMHO time to use underwater cameras to watch what happens after lakers spawn on the very best spot to see if fry emerge and if so what may be there eating eggs or fry. Cordon off the area with buoys and markers off limits to angling and watch the bed closely.  Cormorants? Gobies? Catfish? Perch? siltation? Whitefish? ????? Constant running cameras with researchers watching from the FMU office/lab. We need to know not just make speculative defeatist conclusions like that siltation is the problem and over fishing. No small lakers caught suddenly points to something else in my view any ways. Or a combo of things very drastic rather than gradual hit the laker pop'n. 

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I agree some small lakers should be caught same as small walleyes both Rice and Balsam I've caught some 12 inch walleye.

The clear water makes all specie sight feeding but also makes them every transit  so variable results.

With the size of Simcoe you start driving to find better conditions you can easily just go the wrong way.   

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On 6/14/2020 at 7:14 PM, cisco said:

Hard to say what amount and impact of the amount of 'runoff/silt' is on lakers. As long as a fertilized egg gets oxygen should be good to go. To have all midlake spawning shoals covered by suffocating silt seems a bit far fetched. Some should still be producing lakers. Don't see that though. However a new species such as goby eating small stuff on shoals is something more feasible IMHO. That's why some have been pushing MNHR to properly investigate rather than a tagging study which does not address the spawning habitat issue whatsoever. Perhaps even Goby traps set at spawning shoals can restore spawning success to an acceptable level if this is the case.   

Just my thinking that goby traps will catch a lot more than gobies? It may give them a way to compare the number of small fish species though?

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Other fish can be released and goby killed and stomach contents examined. If goby is why no laker eggs/fry then develop a trapping program. Matter of fact a good idea right now or post spawn to catch goby there and see what they're eating. ZERO excuse not too. Tagging was done but no shoal traps? What ever happened to developing new research for a new problem? 

Is MNR incapable of that? Maybe some university student could think through it and lead the way. (sarcasm intended).

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5 hours ago, cisco said:

Other fish can be released and goby killed and stomach contents examined. If goby is why no laker eggs/fry then develop a trapping program. Matter of fact a good idea right now or post spawn to catch goby there and see what they're eating. ZERO excuse not too. Tagging was done but no shoal traps? What ever happened to developing new research for a new problem? 

Is MNR incapable of that? Maybe some university student could think through it and lead the way. (sarcasm intended).

Get the kids from Fleming down, they'll do anything lol

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Fleming students are technicians who work carrying out the research projects designed and overseen by University grads like with PHDs. Problem with them PHDs is some of them think they know everything but in reality the PHD just means they have a greater understanding how to find/figure stuff out. Not many credible PHDs at MNR these days if tagging studies is the best they got. Only goal of this is to try and determine if a reduced season or slot or harvest or equip restriction or ? should be considered. LOL! We here who fish Simcoe and see/hear what is caught already see the writing on the wall. Maybe MNR can't see it cuz their doctoral diplomas are all on the wall obscuring the OBVIOUS. LOL!!!

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https://realfishing.com/all-about-lake-trout/

" Lake trout spawn in the autumn, between September and December, in water between 48ºF and 57ºF. They prefer to spawn over large areas of lakes with boulder or rubble bottoms but they are also known to occasionally spawn in rivers. The eggs fall into cracks and crevices where they will remain for between four and five-months before hatching in March or April. "

Not something I was aware of, 4 = 5 months for their eggs to hatch? Makes those eggs more of a target if dropped where gobies thrive?

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Anyone actually see any pics from MNR of laker 'spawning shoals' on Simcoe? Any kinda before and after pics as well? As OF reads it does seem they prefer large areas of boulders/rubble. But in Simcoe are they settling for less? Also I have fished many times where light taps and the occasional goby resulted in areas I was after perch. These things eat small stuff like eggs. It's what they do. After opener I have also noticed just after whities have left the shoals and go deep the shoals I fish seem thick with small perch. 

We also need keep in mind that herring didn't take. What happened to them? Could the same 'culprits' be at work? I felt that cormorants were their nightmare since the herring school up often closer to the surface which is perfect for the cormorants to find and destroy, but I think lakers do not generally school up as tight and are in deeper water so..... 

Oh BTW I have noticed far less cormorants than before. Nature doing its thing re cyclic population control perhaps? Or maybe their food source has depleted so they left or starved to the point of lowered reproduction. 

What is REALLY REALLY needed is a properly researched report on what other jurisdictions have been finding out about laker and herring population declines with specific research done on such things as stomach content analysis of possible predators. Getting tired of expert assertions with no field study backing. I mean come on is it that hard to catch and open up stomachs of goby/cormorant/perch? Can't DNA of contents find whether goo in there is really laker egg matter? What do we pay MNR for if not to do such obvious research? 

What mitigation efforts have been tried elsewhere and with what success? To say it's our fault due to siltation/fishing is just fine but is made from behind a desk by someone with a 'defeatist excuse' perspective who wants to keep a big salary without doing anything new/innovative to justify it. 

Honestly, the MNR folks reading this, and they are, should be ashamed if they are not addressing the above. No funding? Then if useless quit if you can't do your job or successfully argue the need too.    

Over the years I have heard many excuses such as "Well it is basically a private lake so....." or, "Well native harvest is bad so....." or "Well development is causing siltation so...."  And have even heard ludicrous claims like "Cormorants have no impact of (insert name of any fish) populations so......" or " Zeba mussels are in there so...."  or "There is no evidence (insert name of any fish) are declining so..." 

Getting to be a joke. Years ago the MNR District Manager gave out press statements on any issue. 'Experts' at MNR would give interviews. Not now. CSB (Communications Services Branch) has taken the place over,  while political party in charge has placed a kindly older lady type at the helm and in nothing gets out without CSB amateur scrutiny and approval for political gain/damage control.

Statements come out from there not at the local level where DMs and RMs make same high salary but have zero accountability to the public. Tail is wagging the dog kinda thing. Politics is behind access road closures/transfers to money/control grubbing municipalities and even worse things are going on to reduce public enjoyment of the outdoors.  

Fun to rant feel a tad better now. Hope it helps readers understand the kind of things going on. Losing ground even though licence fees and lottery money was supposed to assist. Was but once entrenched became another government revenue stream to be pissed away.

Edited by cisco
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1 hour ago, cisco said:

We also need keep in mind that herring didn't take. What happened to them?

I guess it depends in the area you are fishing . I can tell you truthly,KBAY is loaded with them. Any where from 12" down to 6".  I and a few buds can tell you this as we have seen clouds of them under the ice. Also out from BBP this year during the midge hatch,they were jumping all over the place. Seen them come right out of the water right in front of me . Yes,I have not caught any in that 1-2 lb range in probly 4-5 years . One morning Terry and I hit a pod that was in this class range. We were probly 50 ft from each other . That s how many there were .

 

As for the lakers . I have seen them cruise the Barrie marina in the late fall  chasing the shiners, and also around the fountain spit here .  I have heard so good catch days this year,but they have been in different areas then previous . Still though, nothing has been in the 4-6 lb range. All big .

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OK herring in K bay. Good to hear but hardly anyone mentions them caught ice fishing. They were supposed to be a benefit to lakers but have laker stomach contents been asked about to see if so? I haven't caught a herring yet south end but hey, maybe they don't live around 30' and hit small minnow imitations? Are the herring eating shiners or ? Maybe laker fry.....?

Would be nice to see research to see whether the benefit as food source is outweighed by them being a laker fry predator? We used to drop a short line with a trebled pearl below whitie spoons and quickly haul up off bottom to the level the herring school was marked at and get them regular. haven't bothered as herring seem bony and don't appeal taste wise compared to 'yum' whitefish.

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Lakers are eating perch from what I have seen and heard . I have a buddy that down rigs with a large perch body bait. Yup,he gets them. ALL released for your info .

 

As for herring reports,many do not like them,BUT,I do. :good:

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