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  #121  
Old 12-07-2011, 02:02 PM
Dan Foss Dan Foss is offline
 
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Originally Posted by freeones View Post
I read the information. I just don't agree with you regarding how that information is interpreted.

The lack of growth is directly related to the forage base, size, and quality of the water body, I think everyone would agree on that. Put a walleye fry in your fish tank at home, and no matter what or how much you feed it, it isn't going to grow to be a 10lber. Reproduction is limited by the same factors. There won't be a big recruitment year class until there's room in the lake for them to actually compete and survive.

The fishery won't die. It won't stay the same as it is today, but it's not going to die unless it's opened up to unregulated harvest. There is natural reproduction, and the lake has proven that it is capable of sustaining a walleye population. It will find it's own equillibrium, likely one closer to what those who support monkeying around with it want anyway.

I agree it's a stunted walleye population. The difference is, I'm OK with that. If I want to catch fewer bigger fish, I go to a different lake, there's tons of options available for that. If I want to go with kids and catch 100 small ones, I go to PCR. It's a unique lake, and it has a place as is, despite those who wish to change it to meet their definition of a "good" fishery.

understandable and i agree over time it will probably equal out. But here comes the issue. How long does that take? It can take a very very long time for things to occur naturally. so lets say another 7or so years before the two big year classes start dying and then slowly you MAY start seeing greater numbers of young of the year. but for the most part they will probably be fed on by the gigantic pike. But lets say healthy numbers survive. It will take another 6 years to get the first batch of fry back to the size they are now. then it will take another generation of walleye to start evening out the equilibrium between species in the lake. So your looking at 30-40 years. And your not even sure that it will balance itself out.

I would never suggest anything be done to manage the lake without solid research to back any management strategy......


Although I know a particular lake in calgary that has a perch problem that a bucket full of walleye would love to be in.......
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  #122  
Old 12-07-2011, 02:08 PM
Ronbill Ronbill is offline
 
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Great post. What you are talking about perhaps without realizing it is "Population Ecology".

Over-population has some pretty typical outcomes.
A very interesting thread to say the least.

Many of you have touched on key issues, but nobody has hit the root cause. Against my better judgement, I will weigh in on this - I am a registered professional biologist afterall.

Yes BeeGuy it is all about population ecology and it is an over-population issue, but the top predators - the piscivorous fish - are not to blame (not initially). As alluded to earlier by pelada trochu, PCR has a very unbalanced ecosystem and dysfunctional food chain. One only needs to focus on the bottom link of the food chain to know there's a problem (or at least potential for problems). At the bottom, of course, is the phytoplankton - the algae and cyanobacteria (blue-green algae) that form the basis of the food web. I suspect (and I only say 'suspect' as I do not have any hard data - yet - to prove this) the phytoplankton community is unbalanced as it is dominated heavily by large colonial species of cyanobacteria. These are generally what turns the water green during summer and producing the unsightly blooms on many of Alberta's natural lakes and reservoirs during much of the open water season. Cyanobacteria tend to dominate eutrophic lakes - those aquatic systems with high absolute phosphorus concentrations and often low nitrogen relative to phosphorus conditions.

The problem with large colonial cyanobacteria is that very few aquatic organisms digest or even ingest them. Most cyanobacteria are poor food sources for zooplankton (the microscopic animals that graze directly on phytoplankton). Zooplankton will avoid cyanobacteria if at all possible and rather preferentially feed on smaller choice algae including green algae, chysophytes and diatoms. Hell, even larger invertebrates that either indiscriminately graze (i.e. snails) or filter-feed (i.e. mussels) don't actually digest them, but rather pass them through the gut intact (what is known as psuedo-faeces). I discovered this for myself during my Ph.D. research.

Aquatic systems dominated by large cyanobacteria do not support the populations of large-bodied cladoceran zooplankton, like Daphnia (water fleas). This is a problem as the small planktivorous fish - the forage fish - feed primarily on large-bodied zooplankton. This has implications for fisheries management as simply adding forage fish (including young perch) would be a short-lived solution. There simply is no food (zooplankton) to feed forage fish and I will also point out here the necessity for large macrophytes (weeds) to provide safe refuge for forage fish from predators. Must have both food and refugia - pretty basic idea.

Without proper algae, there is no large zooplankton. Without large zooplankton, there is no planktivorous (forage) fish. And without planktivorous fish, there are no piscivorous fish (with time).

Currently, we are left with old stunted top predators that have to feed on large invertebrates live snails, amphipods (Gammarus) and whatever else they can get a hold of. Hardly quality food for sportfish. I have experienced this dysfunction in other cyanobacteria-dominated lakes/reservoirs across the province (Driedmeat Lake near Camrose and Coal Lake near Wetaskiwin immediately come to mind) - sportfish are stunted and gut contents usually include Gammarus and snails - forage fish are rare. What I'm hearing in this thread is very similar to those systems.

As a government employee I guess I should offer some suggestions as to how we can fix this dysfunctional system. The solution is easy - change the phytoplankton community to a more balanced system, that is less cyanobacteria and more edible choice algae. With time the zooplankton community with change to support large-bodied cladocerans that forage fish need and they will flourish too. Then the sportfish will have proper food to support faster growth rates. See simple.

In practice this is not so easy.
The geology of much of Alberta is nutrient (read phosphrous)-rich, thus our lakes tend to naturally support cyanobacteria-dominated systems (no Dorothy, this is not B.C.). On top of that, intense agriculture AND development through much of the settled portion of the province exacerbates the problem (we've all heard the old saying: kill a cow, save a stream ). Changing eutrophic aquatic systems to lower nutrient environments is not easy especially for naturally derived nutrients, but proper manure management - ooops sorry I don't work for the Dept of Agriculture. Besides lunch is over and I'm union so back to work.

Last edited by Ronbill; 12-07-2011 at 02:18 PM.
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  #123  
Old 12-07-2011, 02:20 PM
jrs
 
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Sounds good on paper Ronbill, but this lake is nothing like the ones you mention. THose lakes are shallow weed muddy wetland like lakes, PCR is fairly deep, and fed by foothill/ mountain runoff, very low nutrient (phosphorus included). Not even close to eutrophic, mesotrophic at most. If it wouldn't have been for an expected sucker epidemic like experienced upstream in chain lakes, and cost, im betting trout would have been chosen for stocking instead (on a put and take basis).
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  #124  
Old 12-07-2011, 02:29 PM
Dan Foss Dan Foss is offline
 
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Originally Posted by Ronbill View Post


A very interesting thread to say the least.

Many of you have touched on key issues, but nobody has hit the root cause. Against my better judgement, I will weigh in on this - I am a registered professional biologist afterall.

Yes BeeGuy it is all about population ecology and it is an over-population issue, but the top predators - the piscivorous fish - are not to blame (not initially). As alluded to earlier by pelada trochu, PCR has a very unbalanced ecosystem and dysfunctional food chain. One only needs to focus on the bottom link of the food chain to know there's a problem (or at least potential for problems). At the bottom, of course, is the phytoplankton - the algae and cyanobacteria (blue-green algae) that form the basis of the food web. I suspect (and I only say 'suspect' as I do not have any hard data - yet - to prove this) the phytoplankton community is unbalanced as it is dominated heavily by large colonial species of cyanobacteria. These are generally what turns the water green during summer and producing the unsightly blooms on many of Alberta's natural lakes and reservoirs during much of the open water season. Cyanobacteria tend to dominate eutrophic lakes - those aquatic systems with high absolute phosphorus concentrations and often low nitrogen relative to phosphorus conditions.

The problem with large colonial cyanobacteria is that very few aquatic organisms digest or even ingest them. Most cyanobacteria are poor food sources for zooplankton (the microscopic animals that graze directly on phytoplankton). Zooplankton will avoid cyanobacteria if at all possible and rather preferentially feed on smaller choice algae including green algae, chysophytes and diatoms. Hell, even larger invertebrates that either indiscriminately graze (i.e. snails) or filter-feed (i.e. mussels) don't actually digest them, but rather pass them through the gut intact (what is known as psuedo-faeces). I discovered this for myself during my Ph.D. research.

Aquatic systems dominated by large cyanobacteria do not support the populations of large-bodied cladoceran zooplankton, like Daphnia (water fleas). This is a problem as the small planktivorous fish - the forage fish - feed primarily on large-bodied zooplankton. This has implications for fisheries management as simply adding forage fish (including young perch) would be a short-lived solution. There simply is no food (zooplankton) to feed forage fish and I will also point out here the necessity for large macrophytes (weeds) to provide safe refuge for forage fish from predators. Must have both food and refugia - pretty basic idea.

Without proper algae, there is no large zooplankton. Without large zooplankton, there is no planktivorous (forage) fish. And without planktivorous fish, there are no piscivorous fish (with time).

Currently, we are left with old stunted top predators that have to feed on large invertebrates live snails, amphipods (Gammarus) and whatever else they can get a hold of. Hardly quality food for sportfish. I have experienced this dysfunction in other cyanobacteria-dominated lakes/reservoirs across the province (Driedmeat Lake near Camrose and Coal Lake near Wetaskiwin immediately come to mind) - sportfish are stunted and gut contents usually include Gammarus and snails - forage fish are rare. What I'm hearing in this thread is very similar to those systems.

As a government employee I guess I should offer some suggestions as to how we can fix this dysfunctional system. The solution is easy - change the phytoplankton community to a more balanced system, that is less cyanobacteria and more edible choice algae. With time the zooplankton community with change to support large-bodied cladocerans that forage fish need and they will flourish too. Then the sportfish will have proper food to support faster growth rates. See simple.

In practice this is not so easy.
The geology of much of Alberta is nutrient (read phosphrous)-rich, thus our lakes tend to naturally support cyanobacteria-dominated systems (no Dorothy, this is not B.C.). On top of that, intense agriculture AND development through much of the settled portion of the province exacerbates the problem (we've all heard the old saying: kill a cow, save a stream ). Changing eutrophic aquatic systems to lower nutrient environments is not easy especially for naturally derived nutrients, but proper manure management - ooops sorry I don't work for the Dept of Agriculture. Besides lunch is over and I'm union so back to work.
Very very very cool read. I am still trying to process it.... lol nice work. good to see another bio on board.
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  #125  
Old 12-07-2011, 02:36 PM
Ronbill Ronbill is offline
 
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Sounds good on paper Ronbill, but this lake is nothing like the ones you mention. THose lakes are shallow weed muddy wetland like lakes, PCR is fairly deep, and fed by foothill/ mountain runoff, very low nutrient (phosphorus included). Not even close to eutrophic, mesotrophic at most. If it wouldn't have been for an expected sucker epidemic like experienced upstream in chain lakes, and cost, im betting trout would have been chosen for stocking instead (on a put and take basis).
Actually, both Driedmeat and Coal Lakes were formed in a similar manner (ok they are online reservoirs as opposed to offline) as PCR. They are all reservoirs with flow control structures. The big diff is that PCR is relatively young compared to the other two.

I checked the recent nutrient data and one basin of PCR is mesotrophic and the other is classified as eutrophic. More recently we (Alberta Environemnt) have began monitoring lakes and reservoirs including PCR for the microcystin toxin - a liver toxin produced by some species of large colonial cyanobacteria. It does show up in PCR (and Chain lakes res too), which leads me to conclude the dominance of cyanobacteria in PCR at least from July through September. For us to obtain microcystin levels in excess of 1 ug/L of lake water, high biomass of toxin-producing cyanobacteria is required.
I should also take this oportunity to dispell any other myths around toxic cyanos, namely: cyanobacteria exist in all aquatic ecosystems naturally and not all species grow exclusively in nutrient rich, shallow waters. There are some species that prefer mesotrophic (lower nutrient) systems and produce several types of toxin. Fortunately these species do not form blooms at the surface but rather congregate at deeper depths where light intensity is much reduced. These species grow and photosynthesize optimally in low light. Coincidentally, these species are also responsible for turning some lakes/reservoirs red immediately following ice during spring. Don't drink that water.

Last edited by Ronbill; 12-07-2011 at 02:42 PM.
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  #126  
Old 12-07-2011, 02:44 PM
Dan Foss Dan Foss is offline
 
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Originally Posted by Ronbill View Post
I checked the recent nutrient data and one basin of PCR is mesotrophic and the other is classified as eutrophic. More recently we (Alberta Environemnt) have began monitoring lakes and reservoirs including PCR for the microcystin toxin - a liver toxin produced by some species of large colonial cyanobacteria. It does show up in PCR (and Chain lakes res too), which leads me to conclude the dominance of cyanobacteria in PCR at least from July through September. For us to obtain microcystin levels in excess of 1 ug/L of lake water, high biomass of toxin-producing cyanobacteria is required.
I should also take this oportunity to dispell any other myths around toxic cyanos, namely: cyanobacteria exist in all aquatic ecosystems naturally and not all species grow exclusively in nutrient rich, shallow waters. There are some species that prefer mesotrophic (lower nutrient) systems and produce several types of toxin. Fortunately these species to not form bloms at the surface but rather congregate at deeper depths where light intensity is much reduced. These species grow and photosynthesize optimally in low light. Coincidentally, these species are also responsible for turning some lakes/reservoirs red immediately following ice during spring. Don't drink that water.

It does make sense. PCR is one of the greenest lakes that I have ever seen in mid summer. It gets so green that visibility is often only approximately 3-4 feet. Not kidding. my buddy had dropped a brand new rod I bought for him in the lake and we made him attempt to dive for it (approx 24 feet deep. We knew there was no way he would get it but we wanted to laugh at him while he tried.)when he was hanging onto the boat, the water was so discoloured that you could only see the top of his legs; couldnt see his knees or feet. I made note of that as I would never want to dive into that water myself.
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  #127  
Old 12-07-2011, 02:52 PM
Ronbill Ronbill is offline
 
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It does make sense. PCR is one of the greenest lakes that I have ever seen in mid summer. It gets so green that visibility is often only approximately 3-4 feet. Not kidding. my buddy had dropped a brand new rod I bought for him in the lake and we made him attempt to dive for it (approx 24 feet deep. We knew there was no way he would get it but we wanted to laugh at him while he tried.)when he was hanging onto the boat, the water was so discoloured that you could only see the top of his legs; couldnt see his knees or feet. I made note of that as I would never want to dive into that water myself.
I thought so. I talked to my field staff in the Calgary office (as I unfortunately never made it out to PCR to see for myself) and they also said it can get quite green.
I'll say this, bloom-forming cyanobacteria does discriminate based on water depth. What is critical is that PCR is a relatively stagnant (read: low flow) system and with enough nutrient to satisfy growth and dominance by bloom-forming cyanos. If PCR was an online system recceiving very low nutrient water from the Bow River for instance, then the situation would be different - cyanobacteria would likely not dominate.
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  #128  
Old 12-07-2011, 03:01 PM
Dan Foss Dan Foss is offline
 
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I thought so. I talked to my field staff in the Calgary office (as I unfortunately never made it out to PCR to see for myself) and they also said it can get quite green.
I'll say this, bloom-forming cyanobacteria does discriminate based on water depth. What is critical is that PCR is a relatively stagnant (read: low flow) system and with enough nutrient to satisfy growth and dominance by bloom-forming cyanos. If PCR was an online system recceiving very low nutrient water from the Bow River for instance, then the situation would be different - cyanobacteria would likely not dominate.
Very interesting. so what exactly can be done to control cyanobacteria? is it strictly because it is a low flow res. with minimal neutrients? is it even something that can even be managed? Are there and plants or other organisms that can keep cyanobacteria at low levels?
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  #129  
Old 12-07-2011, 03:01 PM
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understandable and i agree over time it will probably equal out. But here comes the issue. How long does that take? It can take a very very long time for things to occur naturally. so lets say another 7or so years before the two big year classes start dying and then slowly you MAY start seeing greater numbers of young of the year. but for the most part they will probably be fed on by the gigantic pike. But lets say healthy numbers survive. It will take another 6 years to get the first batch of fry back to the size they are now. then it will take another generation of walleye to start evening out the equilibrium between species in the lake. So your looking at 30-40 years. And your not even sure that it will balance itself out.

I would never suggest anything be done to manage the lake without solid research to back any management strategy......

Although I know a particular lake in calgary that has a perch problem that a bucket full of walleye would love to be in.......
I see good news in your post, not doom. You're suggesting that things will remain pretty much as they are for the next 7 or more years, and that without the fishery collapsing, it will correct itself over time with no need for outside interference.

It's been shown that PCR can support young of the year and fingerlings to maturity in the past, that tells me it can do it again if the biomass base is available for their growth. Yes there are lots of predators, but EVERY lake has lots of predators.

Opening up PCR to harvest will simply speed up the process of removing the two main year classes, drastically if it isn't strictly controlled. It won't fundamentally change the rate at which the walleye population replenishes itself, it's still going to take the same amont of time. All that's been accomplished is to decrease the walleye population artificially and move the timetable for change ahead by a few years. I don't see the point in that.

I don't see adding a bunch of forage fish as an option either, Ronbill makes a good argument for that being a failure, and again, there's limited biological carrying capacity.

So what are the remaining options? Stocking again? At this stage, I think it would be pointless, it's already at max capacity. It might be a very viable option in the future to help supplement the walleye's natural recruitment rate if the quality of the fishery really suffers.

The only other option is exactly what Ronbill suggests, and that's trying to improve the quality of the water and boost the bottom links of the food chain. I don't know how you do that, but that's something that I could support.

It's all well and good to want to do something, but doing something just for the sake of doing it is not sound reasoning, nor is a personal preference for the type of fishing that exists in a certain lake.
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  #130  
Old 12-07-2011, 03:08 PM
Dan Foss Dan Foss is offline
 
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I see good news in your post, not doom. You're suggesting that things will remain pretty much as they are for the next 7 or more years, and that without the fishery collapsing, it will correct itself over time with no need for outside interference.

It's been shown that PCR can support young of the year and fingerlings to maturity in the past, that tells me it can do it again if the biomass base is available for their growth. Yes there are lots of predators, but EVERY lake has lots of predators.

Opening up PCR to harvest will simply speed up the process of removing the two main year classes, drastically if it isn't strictly controlled. It won't fundamentally change the rate at which the walleye population replenishes itself, it's still going to take the same amont of time. All that's been accomplished is to decrease the walleye population artificially and move the timetable for change ahead by a few years. I don't see the point in that.

I don't see adding a bunch of forage fish as an option either, Ronbill makes a good argument for that being a failure, and again, there's limited biological carrying capacity.

So what are the remaining options? Stocking again? At this stage, I think it would be pointless, it's already at max capacity. It might be a very viable option in the future to help supplement the walleye's natural recruitment rate if the quality of the fishery really suffers.

The only other option is exactly what Ronbill suggests, and that's trying to improve the quality of the water and boost the bottom links of the food chain. I don't know how you do that, but that's something that I could support.

It's all well and good to want to do something, but doing something just for the sake of doing it is not sound reasoning, nor is a personal preference for the type of fishing that exists in a certain lake.
LOL. I never states as a fact that things wont change, I was just following by the logic of the people who have been saying do nothing and that the fishery is fine as is. I cannot tell you if it will be fine for future years or not. I also agree that RonBill has provided a great deal of insight that completely changes positions and stance on the lake. and that should be the starting point
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  #131  
Old 12-07-2011, 03:23 PM
Ronbill Ronbill is offline
 
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I see good news in your post, not doom. You're suggesting that things will remain pretty much as they are for the next 7 or more years, and that without the fishery collapsing, it will correct itself over time with no need for outside interference.

It's been shown that PCR can support young of the year and fingerlings to maturity in the past, that tells me it can do it again if the biomass base is available for their growth. Yes there are lots of predators, but EVERY lake has lots of predators.

Opening up PCR to harvest will simply speed up the process of removing the two main year classes, drastically if it isn't strictly controlled. It won't fundamentally change the rate at which the walleye population replenishes itself, it's still going to take the same amont of time. All that's been accomplished is to decrease the walleye population artificially and move the timetable for change ahead by a few years. I don't see the point in that.

I don't see adding a bunch of forage fish as an option either, Ronbill makes a good argument for that being a failure, and again, there's limited biological carrying capacity.

So what are the remaining options? Stocking again? At this stage, I think it would be pointless, it's already at max capacity. It might be a very viable option in the future to help supplement the walleye's natural recruitment rate if the quality of the fishery really suffers.

The only other option is exactly what Ronbill suggests, and that's trying to improve the quality of the water and boost the bottom links of the food chain. I don't know how you do that, but that's something that I could support.

It's all well and good to want to do something, but doing something just for the sake of doing it is not sound reasoning, nor is a personal preference for the type of fishing that exists in a certain lake.
Dan, as humans we tend to always look from the top down (i.e. focussing on the sportfish). However, getting to the root of the problem (i.e. cyanobacteria dominace) means bottom-up in this case and is the only sustainable way of changing the fishery over the long-term.

It would be pointless to continue stocking sportfish in PCR and I suspect some limited harvest of fish could help - just don't tell my counterparts in SRD I said that
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  #132  
Old 12-07-2011, 03:34 PM
Dan Foss Dan Foss is offline
 
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Dan, as humans we tend to always look from the top down (i.e. focussing on the sportfish). However, getting to the root of the problem (i.e. cyanobacteria dominace) means bottom-up in this case and is the only sustainable way of changing the fishery over the long-term.

It would be pointless to continue stocking sportfish in PCR and I suspect some limited harvest of fish could help - just don't tell my counterparts in SRD I said that
I think you mean Freeones, not dan. I am against stocking. stocking if for put and take trout lakes IMO
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  #133  
Old 12-07-2011, 03:52 PM
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Thank you, very much, for your sound contributions to this thread, Ronbill. It is refreshing to hear from someone with knowledge about the specific situation that PCR is facing.
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  #134  
Old 12-07-2011, 04:35 PM
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Thanks for weighing in Ronbill. Appreciate the information!
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  #135  
Old 12-07-2011, 04:48 PM
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glad there is someone out there who REALLY understands this process.
Very much applaude the buttom up approach to establishing a fishery. Takes longer and most of us are used to getting our Big Mac now.

I dont know how you adjust the bottom but one thing apparent from the above read was that the fry cant survive because there is no food for them. That kills just about every idea until you have a food source for the beginning segment of the fish chain.

establish that food source for the fry, habitat for them to hide and the problem is solved as everything will grow from there. The current year class will die out but begin to be replaced.

just because you see crows feeding in a mall parking lot doesnt mean its a good place to raise birds.
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  #136  
Old 12-07-2011, 07:24 PM
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I think you mean Freeones, not dan. I am against stocking. stocking if for put and take trout lakes IMO
Right you are Dan, the stocking reference was not directed at you.

I'm very happy you and others recognize nothing will change (likely get worse) unless we manage things carefully.
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Old 12-07-2011, 08:48 PM
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you question is a good one, I guess that's why we take the older grandson and his Dad to Crawling. Generally a very different expearence, but bigger walleye, I seem to be stuck at 67 cm. However Crawling is a full day and the little guys are just a little young, sometimes it take awhile to figure out what they want etc. When i think about it thats the value I see at Pine Coulee, take a newby, my older girls, the Grandkids, new Canadians, it just doen't matter they catch fish. i have yet to have them ask for bigger fish, Pine Coulee sparks their interest in the sport of fishing like nothing else i know.

here a big guess, the mortality from catch n release is a factor and eventually all things will even out.

To me i would hate to see additional harvest on any of the Southern Reservoirs. Basically some people are piggy, again a guess but a zero limit is way easier to enforce with the very limited SRD budgets.
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  #138  
Old 12-07-2011, 09:08 PM
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Basically some people are piggy, again a guess but a zero limit is way easier to enforce with the very limited SRD budgets.
not sure I understand the reasoning behind that statement, if the officer is checking for fish possession, how long does it take to hold a measuring device beside the fish , hes already invested the time to stop the person and search his boat/vehicle. takes a couple seconds to measure each one. if there is a zero limit he still has to do the same search and ask the same questions. so 4 extra seconds only takes what, 4 seconds?
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  #139  
Old 12-07-2011, 09:56 PM
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I see good news in your post, not doom. You're suggesting that things will remain pretty much as they are for the next 7 or more years, and that without the fishery collapsing, it will correct itself over time with no need for outside interference.

It's been shown that PCR can support young of the year and fingerlings to maturity in the past, that tells me it can do it again if the biomass base is available for their growth. Yes there are lots of predators, but EVERY lake has lots of predators.

Opening up PCR to harvest will simply speed up the process of removing the two main year classes, drastically if it isn't strictly controlled. It won't fundamentally change the rate at which the walleye population replenishes itself, it's still going to take the same amont of time. All that's been accomplished is to decrease the walleye population artificially and move the timetable for change ahead by a few years. I don't see the point in that.

I don't see adding a bunch of forage fish as an option either, Ronbill makes a good argument for that being a failure, and again, there's limited biological carrying capacity.

So what are the remaining options? Stocking again? At this stage, I think it would be pointless, it's already at max capacity. It might be a very viable option in the future to help supplement the walleye's natural recruitment rate if the quality of the fishery really suffers.

The only other option is exactly what Ronbill suggests, and that's trying to improve the quality of the water and boost the bottom links of the food chain. I don't know how you do that, but that's something that I could support.

It's all well and good to want to do something, but doing something just for the sake of doing it is not sound reasoning, nor is a personal preference for the type of fishing that exists in a certain lake.


Can you show where you got this information from.
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  #140  
Old 12-08-2011, 08:10 AM
freeones freeones is offline
 
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Can you show where you got this information from.
I find it odd that out of that whole post, that's the part you chose to single out, but just in case you're actually serious and you really don't understand, I'll explain it for you -

The walleye population in PCR is not native, it was introduced through the stocking of walleye. Walleye stocking is generally done using fingerlings, approximately 1-4cm in size. Those fingerlings thrived in PCR and represent the vast majority of the walleye population present in the lake today. Anecdotal and SRD data also shows that there is recruitment in PCR, however, it's limited by available forage and competition for that forage.

Based on that data, there's no reason to believe that PCR is not capable of supporting the young of the year and/or fingerlings to maturity in the future. No magic here, just the info readily available in this thread combined with some common sense.

Last edited by freeones; 12-08-2011 at 08:23 AM.
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  #141  
Old 12-08-2011, 08:14 AM
freeones freeones is offline
 
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I think you mean Freeones, not dan. I am against stocking. stocking if for put and take trout lakes IMO
Actually, I thought I made my thoughts on stocking pretty clear -

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Originally Posted by freeones
So what are the remaining options? Stocking again? at this stage, I think it would be pointless it's already at max capacity. It might be a very viable option in the future to help supplement the walleye's natural recruitment rate if the quality of the fishery really suffers.
ie, if the current year classes are lost, the population drops off dramatically, and the evidence suggests that natural recruitment can't fill the gap, at that point, I think further stocking would be an option.
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  #142  
Old 12-08-2011, 08:21 AM
freeones freeones is offline
 
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double post
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  #143  
Old 12-08-2011, 09:02 AM
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When the old walleye start dying off you'll see new ones move in or another species take their place. If there's an open niche, it will be filled. The original walleyes used for stocking looked like hairs when they were released, they grew up. More recent seining shows successful recruitment. Remember, seining isn't meant to be used quantitatively, it's to demonstrate spawning success in this case. It's a big lake, walleyes fry will be found in many many places not sampled or even suitable for seining.
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  #144  
Old 12-08-2011, 11:52 AM
horsetrader horsetrader is offline
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From SRD
2.3 million Walleye fry were stocked in Pine Coulee Reservoir in the spring of 2000, with another 1.8 million stocked in the spring of 2002. Stocking of cyprinids and suckers collected from Willow Creek was also done in 2000 to try to establish a forage base for Walleye. Since then we have sampled the reservoir to monitor the Walleye population as it develops. In 2003, 2004, 2007, and 2009 gill netting was conducted to sample for larger Walleye in open, deeper areas of the reservoir. In 2005 and 2006 test angling was conducted to further sample larger Walleye for mercury analysis. In 2003, 2004, 2007, 2008, and 2009 beach seine netting in shallow areas of the reservoir was conducted to sample for juvenile Walleye (young of the year).



Gill net results

In 2003 over 60 Walleye were caught with an average fork length of about 10-11 inches. These were from the 2000 stocking event.

In 2004 close to 100 Walleye were caught with an average fork length of about 11-12 inches.

In 2007 about 50 Walleye were caught with an average fork length of about 13 inches.


In 2009 almost 130 Walleye were caught with an average fork length just over 13 inches. Stomach contents were analysed and ages determined. Only a single Walleye was less than 12 inches fork length. Its fork length was about 9.5 inches and it was aged 2 years old. This fish is believed to have resulted from natural spawning (not a stocked fish). All the other Walleye were between 12 and 15 inches long and either age 6 or age 9. They came from either the 2000 or 2003 stocking events. Stomach content analysis showed that of all the Walleye caught in 2009, only one contained partially digested fish, while all others either had empty stomachs or only invertebrates in their stomachs, mostly amphipods (Gammarus).



Test angling results

In 2005 35 Walleye caught in the spring had an average fork length of 12 inches.

In 2006 31 Walleye caught in the spring had an average fork length of 13 inches.



Beach seining results

In 2003 no young of the year Walleye were captured.

In 2004 no young of the year Walleye were captured.

In 2007 5 young of the year Walleye were captured at a single site.

Walleye spawning was also confirmed in 2007 though the use of egg traps set over spawning habitat, mid-April though mid-May.

In 2008 5 young of the year Walleye were captured at two sites.

In 2009 7 young of the year Walleye were captured at four sites.

All young of the year Walleye were around 1.5 inches long.



Ten years after completion of the Pine Coulee Project, the overall conclusion from these results is that a dense population of Walleye from the 2000 and 2003 stocking events has developed, but the growth rate of these fish has gradually decreased to the point that they have almost stopped growing now. Although spawning is occurring, there appears to be very limited survival of naturally spawned young (only one fish caught in gill nets in 2009 was a two year old). Stomach content analyses demonstrate Walleye are not feeding on fish, but primarily on amphipods (invertebrates). This is likely limiting their growth. All fish but the one age 2 fish sampled in 2009 did appear to have mature gonads, suggesting they could spawn, but the limited prey base may mean not all Walleye have sufficient energy to actually spawn. Another possibility is that despite successful spawning, very few young of the year survive the first summer due to poor conditions for survival (cold weather, wind and wave action, poor rearing habitat) or larval predation by other forage species present in the reservoir. Beach seine netting in shallow areas of the reservoir has shown White Suckers and Longnose Suckers are abundant, but the Walleye are not feeding on them. Other species of forage fish such as Lake Chub, Spottail Shiners, Emerald Shiners, and Fathead Minnow are also present, but in lower numbers.



Walleye fisheries across Alberta are classified into one of four management categories. In southern Alberta, all waterbodies were classified into one of two categories: newly stocked or vulnerable. Reservoirs and lakes in the first category have a zero catch limit (catch and release) while those in the vulnerable category allow for limited harvest. According to Alberta's Walleye Management and Recovery Plan, changes to the management status category (e.g., from newly stocked to vulnerable) are based on five biological characteristics: age-class distribution, age-class stability, growth, age-at-maturity, and catch rate. Although catch rate meets the criteria for changing the status category of Pine Coulee Reservoir,growth rate, age-at-maturity, age-class distribution, and age-class stability do not. Walleye in Pine Coulee Reservoir have reached maturity rapidly, the age-class distribution is extremely narrow (essentially only fish from the 2000 and 2003 stocking events are represented), and age-class stability is very low (if these two age classes were lost to overharvest there would be no younger age classes to fill their place). In order to change Pine Coulee Reservoir from the newly stocked to vulnerable category we need to have biological evidence that juvenile Walleye are surviving, reaching sexual maturity, and spawning successfully.



We will continue to monitor the reservoir and evaluate the feasibility of various options for establishing a sustainable fishery. A risk assessment considering the impacts to the reservoir itself, as well as to Willow Creek, would be required before considering introducing another prey species for Walleye. In terms of allowing limited harvest, a decision will have to be reach on whether a self sustaining Walleye fish can be established before this is considered. One factor to note is that a consumption advisory is in place for Walleye from this reservoir. Although concentrations of total mercury in analysed walley from Pine Coulee Reservoir (0.52 to 0.79 micrograms/gram) were within reported ranges for Walleye from rivers and lakes elsewhere in Canada and the United States, they were also above the threshold (0.5 micrograms/gram) where Health Canada recommends limits for consumption for different consumer groups (women, children, adults).



If you have any further questions about fisheries management on Pine Coulee Reservoir, please feel free to contact me again.
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Originally Posted by freeones View Post
I find it odd that out of that whole post, that's the part you chose to single out, but just in case you're actually serious and you really don't understand, I'll explain it for you -

The walleye population in PCR is not native, it was introduced through the stocking of walleye. Walleye stocking is generally done using fingerlings, approximately 1-4cm in size. Those fingerlings thrived in PCR and represent the vast majority of the walleye population present in the lake today. Anecdotal and SRD data also shows that there is recruitment in PCR, however, it's limited by available forage and competition for that forage.

Based on that data, there's no reason to believe that PCR is not capable of supporting the young of the year and/or fingerlings to maturity in the future. No magic here, just the info readily available in this thread combined with some common sense.

Oh yes I'm serious. The data show there is natural spawning but it is so minor that there is no way the fishery can sustain itself. The growth of the walleye has virtually stop and spawn in is almost non existent. That is the data and combine that with common sense and you have a fishery in trouble.
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  #145  
Old 12-08-2011, 01:28 PM
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yes. thank-you Ronbill for your insightful and informative posts.

your statement “Without proper algae, there is no large zooplankton. Without large zooplankton, there is no planktivorous (forage) fish. And without planktivorous fish, there are no piscivorous fish (with time),” to me does sum up the current status of the ecology in question and makes sense. that combined with the determined current poor habitat (both walleye spawning/rearing and baitfish) noted by the SRD, brings me back to my questions posed back in post #100.


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Originally Posted by Daceminnow View Post
i wonder if there's any plans to improve the habitat. i know stream improvements in the province have been done to improve spawning and rearing grounds. is it possible for these same types of habitat improvements to be made in lakes and reservoirs as well? or is it just that PCR is a relatively new reservoir and it will take some time to develop new and better habitat for the young to utilize and survive? we stay out of it, and let the ecosystem look after itself and our fish.

if yourself as well as some of the other government connected members could comment on my questions, i’d like to hear any thoughts and suggestions concerning habitat improvements. one way or another.

thanks,

Dace
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  #146  
Old 12-08-2011, 01:46 PM
freeones freeones is offline
 
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Originally Posted by horsetrader View Post
Oh yes I'm serious. The data show there is natural spawning but it is so minor that there is no way the fishery can sustain itself. The growth of the walleye has virtually stop and spawn in is almost non existent. That is the data and combine that with common sense and you have a fishery in trouble.
I really don't know what else I can say, I think you missed my point entirely.

The fact is, the stocking of PCR was incredibly successful. The survival rate amongst the stocked walleye was obviously very high. The lake has since reached it's current max. carrying capacity, so survival of young of the year or additional stocked walleye would be expected to be very low. Others have commented on the recruitment success, reasons for it, and the validity of the seine results, I don't think I need to rehash it. The point is a simple one, the initial success and the current population bodes well for the lake's ability to replenish itself in the future.

I don't perceive the slowing of growth of the population as a problem, it's a natural reaction to the conditions in the lake. Again, not every fishery needs to be managed as a trophy fishery.

You've commented a lot about the perceived problems at PCR, but I'd love to know what specifically you would do solve those "problems".
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  #147  
Old 12-08-2011, 06:53 PM
huntsfurfish huntsfurfish is offline
 
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Originally Posted by horsetrader View Post
Oh yes I'm serious. The data show there is natural spawning but it is so minor that there is no way the fishery can sustain itself. The growth of the walleye has virtually stop and spawn in is almost non existent. That is the data and combine that with common sense and you have a fishery in trouble.
Where did it say that? Actually, what was posted may indicate just the opposite.
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  #148  
Old 12-09-2011, 11:26 AM
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Where did it say that? Actually, what was posted may indicate just the opposite.
I think one's perception of the data is affected by whether or not someone is a "glass half full" or "glass half empty" type of person.

I personally found the data that was posted to be incredibly encouraging. There is proof of successful spawning (limited or not), and I have heard it said several times that the "walleye don't spawn in PCR." Apparently they do.

This is a young and man-made fishery: a scientific experiment of sorts. There is a lot of encouraging news in what was posted (if one cares to recognize it).

And honestly, when it comes to PCR, I can not for the life of me figure out what the fuss is all about. Are people being alarmists strictly to stir the pot? I can think of bigger things to get worked up about. Rome wasn't built in a day.

I'm also wondering how many of the alarmists have actually fished this lake.
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  #149  
Old 12-09-2011, 01:05 PM
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Habitat improvement potential, as mentioned above, is possible in reservoirs. It is however expensive, and carries no guarantee of success. If you research it (i remember looking into this several years ago in college) there is a few success stories, and id say even more failures. Personally, i think Pine Coulee needs time for substrates to become more organic meaning more weeds and food production. There's other things that could be tried, realistically however, way too expensive considering the limited benefits you'd likely realize.
It was designed for walleye, the multi million dollar inlet canal and screens were intended to prevent other fish from getting in for as long as possible. Failed the first year as burbot fry fit right through (i walked along the canal at that point, you could see hundreds of burbot fry which came from willow creek).
They incorporated a lot of walleye spawning habitat, and as such it was kind of destined to become what it currently is. How many people realize the number of walleye stocked was actually considered low considering survival rates of fish that size? Initially, plans included more walleye over more years. Apparently, survival of the initial stockings was more succesful than anticipated. Fun to discuss what could be done, but i'm secretly hoping they just leave it alone.
Ive done seining on some irrigation canals that flow out of a popular walleye lake down here annually since i was very young as part of the salvage fishery (family has done this for 25years), over all the years, we've caught less than 10 juvenile walleye, compare that to litterally thousands upon thousands of whitefish, hundreds of pike, and dozens of mature walleye (3-10 lbs). the average pull would also have around 500-1000 forage fish (shiners, sculpins, fathead minnows, etc). No walleye have been stocked in the upstream lake recently, its still a great fishery, you don't need thousands of fry to show up in sampling to have a good walleye fishery, you just end up with bigger fish.
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  #150  
Old 12-09-2011, 05:31 PM
horsetrader horsetrader is offline
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Originally Posted by huntsfurfish View Post
Where did it say that? Actually, what was posted may indicate just the opposite.
You are possibly right I should not have worded it that way but rather Although spawning is occurring, there appears to be very limited survival of naturally spawned young (only one fish caught in gill nets in 2009 was a two year old) Now could it be that what spawning there is the fry are being eaten as there is a low numbers of bait fish in the res.
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