"Invasive" Species?

[intothedeep]

As extreme as it sounds...yes.

People often say a lake is barren and stocked splake or brook trout cause no harm.

If the lake is truly barren, how does it support these fish then? Would the fish not die of starvation?

Truth of the matter is...the lake is barren of SPORTFISH...but not other native species such as frogs, minnow species, darter species, sucker and redhorse species, sometimes even Round Whitefish. Let's not forget the invertebrates...insects, zooplankton, worms, leeches..etc. So stocking these top end predator is in fact introducing unnecessary stress to the ecosystem of the lake. It is causing harm to provide us with a place to fish.

People often don't take a holistic approach to the argument...but only view the issue from the point of view that affects them. Saying a lake is barren and it should receive planting of sportfish is simply justification to creating "sport", rather than benefiting the natural environment.

As for the other comments on keeping bass or pike where they are invasive - I'm not saying you kill them like you would to gobies and waste sportfish...because it is illegal (although...we can argue whether these invasive sportfish in their unnatural and non-historical range should still receive the same protection and status). However, I see people releasing pike in Haliburton lakes, and people applaud having Smallmouth Bass in natural Brook Trout and Lake Trout lakes. Such is my argument that people have these biased views on biodiversity and their use of "invasive" species...throwing the term when it justify their desired, but abandoning that term when it goes against their wishes.

Don't get me started on Pacific Salmon, Rainbow Trout and Brown Trout in Lake Ontario. I do understand the salmon function as a biological control toward the Alewife population...but we know now that the Alewife population is on the decrease yet there are still cries to maintain or increase stocking. Rainbow Trout and Brown Trout really should have no places in Lake Ontario in my opinion. They have a more varied diet and more likely to prey on native Lake Ontario species, not to mention compete with native Brook Trout and prey on Brook Trout fry in the headwaters.

Pacific Salmon is a double edge sword. On one hand, they do prey heavily on Alewife. Controlling Alewife population will ultimately help toward the reestablishment of deepwater cisco species. It's sad though that a few species had already extincted or extirpated in the Great Lakes. However, Pacific Salmon, particular those in Lake Superior, had also been found to prey on cisco (not necessarily deepwater cisco as those species are usually too deep). So careful management is needed. At the end, the ministry must weight the pros and cons of Pacific Salmon in the lake and act in the best interested of the Great Lakes...not necessarily tailoring the decision to satisfy Ontario anglers.

Do I enjoy catching salmon, Rainbow Trout and Brown Trout, yes...certainly. I can't deny it. But at the same time, it doesn't mean it is the right thing to keep them around now that our understanding of native biodiversity and interactions between non-native predators and native prey occurs.

Some good points, but to play devils advocate... If an ecosystem has been altered to the point it longer holds the original natives. Some Southern ON tribs can no longer hold specs or Atlantics, but bows, Pacifics and browns do well. Then is it not better to bring in outsiders to fill the gap? Also at what point do outsiders become native? Browns have been here 100 years and fill a great role and are self sustaining, as far as I'm concerned they are now native!

Also to your spec example... If humans emptied the lake and made it barren, what's the harm in re-stocking?

Also in nature speacies do travel by birds or currents, etc. So invasives happen naturally, but we've sped it up indeed. Wild life management is no easy feat... Just stuff to think about.

[MuskieBait]

Some good points, but to play devils advocate... If an ecosystem has been altered to the point it longer holds the original natives. Some Southern ON tribs can no longer hold specs or Atlantics, but bows, Pacifics and browns do well. Then is it not better to bring in outsiders to fill the gap? Also at what point do outsiders become native? Browns have been here 100 years and fill a great role and are self sustaining, as far as I'm concerned they are now native!

Also to your spec example... If humans emptied the lake and made it barren, what's the harm in re-stocking?

Also in nature speacies do travel by birds or currents, etc. So invasives happen naturally, but we've sped it up indeed. Wild life management is no easy feat... Just stuff to think about.

All valid points and I agree with all of them actually. I like devil's advocates.

So if that is the case, if we altered an environment badly enough (Great Lakes with Zebra Mussel infestation), and now a biological control is available (Round Goby), with an additional bonus that this biological control also add to the food chain (predator being smallmouth bass, walleye, freshwater drum, and lake whitefish), then should be kill Round Goby indiscriminantly in lakes and rivers where they are already well established? (Because, anglers like to kid themselves and think that the dozen they kill actually has an impact on the millions that are already breeding in the Great Lakes)

If a stormwater pond, those that are now very commonly established in residential complexes are eutrophic and polluted with residential waste (car washing soap, road salt, antifreeze, fertilizers, pesticides), and common carp and goldfish happened to be in these ponds when nothing else can really survive, should anglers be indiscriminantly killing these "invasive" species? Should anglers push for removal of these "pest" and stocking of "sportfish" when sportfish cannot survive such harsh conditions?

When common carp has been established in the Great Lakes for so long, and they are reproducing successfully while providing great sport, then at which point do we consider them as "native" and no longer "invasive"? I'm mirroring your point regarding Brown Trout, Rainbow Trout and Pacific Salmon. Why do I focus on Common Carp? Once upon a time, Lake Ontario was a great producer of Lake Sturgeon, a fish that was extremely great in number until overfishing wiped them out. They are bottom feeders just like Common Carp. Now that Lake Sturgeon are gone, Common Carp can be seen as replacing this void of bottom feeders. So if you argue that Brown Trout fulfill a niche that Atlantic Salmon can no longer satisfy, then I argue that Common Carp fulfill a niche that Lake Sturgeon no longer satisfy. So can we stop considering Common Carp as an "invasive" and start calling them native?

* Yes, I do realize that Common Carp not only feed on the bottom, but the main concern with them includes uprooting aquatic habitat, which is the real detrimental effect they have on the ecosystem. But, for argument sake, they do fulfill similar role as Lake Sturgeon.

If human made a lake barren and restock a species that our actions had wiped out, then it is a reestablishment effort (Atlantic Salmon is a prime example of such effort...but we won't argue whether this effort is worthwhile or not). It is very different from introducing a species to a "barren" lake that formerly does not have such species. The MNR has, in the past and still to some degree currently, sought to create "new and additional fishing opportunities" by stocking sportfish in new locations where they do not occur historically.

If species spread naturally, as in your example that birds or current carry them around, then how is it different that an ocean crossing tanker, carrying basalt water from the Black Sea with some Zebra Mussel embryo is more detrimental than a piece of driftwood that has Zebra Mussel attached, surviving the long and miraculous journey across the Atlantic and eventually drifted into the St. Lawrence River, where the mussels can then be established and eventually spread into the Great Lakes? (I know the difference...it is a time and probability question...but for argument sake, in a philosophical way and not necessarily a practical way...let's think about it a little). Yes, the establishment of a new species in a location separated at such great distance is very remote, but there are real examples of amphibians, reptiles, fish and even mammals that have crossed oceans, adapted and eventually evolved into new species on islands separated by great bodies of water.

I don't expect answers...but just points I like to propose for people to think about.

Yes, wildlife and resource management is not an easy thing.

[Habs]

Carp turn a shallow super fertile estuary to a giant sterile mud flat. The negative effect they have (primarily due to spawning habits) on local species has been clear and documented. They are indeed an invasive species totally unlike the lake sturgeon, totally different habitat and preferrred food/water temps/etc. I think that is a strange comparison. Having said that, I sure wouldn't club one and toss it back in the water
They also provide a recreational fishery totally overlooked and ignored by most anglers here in ON, not that an animals "worthiness" is relative to human entertainment, if more people fished for carp (and I know, it's happening), perhaps it may lighten the pressure on other species.

[MuskieBait]

Carp turn a shallow super fertile estuary to a giant sterile mud flat. The negative effect they have (primarily due to spawning habits) on local species has been clear and documented. They are indeed an invasive species totally unlike the lake sturgeon, totally different habitat and preferrred food/water temps/etc. I think that is a strange comparison. Having said that, I sure wouldn't club one and toss it back in the water
They also provide a recreational fishery totally overlooked and ignored by most anglers here in ON, not that an animals "worthiness" is relative to human entertainment, if more people fished for carp (and I know, it's happening), perhaps it may lighten the pressure on other species.

Yes...I have already stated that.

"* Yes, I do realize that Common Carp not only feed on the bottom, but the main concern with them includes uprooting aquatic habitat, which is the real detrimental effect they have on the ecosystem. But, for argument sake, they do fulfill similar role as Lake Sturgeon."

As for carp using different habitat, preferred food, water temps...etc...it depend on which area you are fishing for carp. On the St. Lawrence, it is not uncommon to be fishing for carp and catch a Lake Sturgeon incidentally. On the flip side, it is also very common to be fishing for Lake Sturgeon and catch Common Carp. So depending on the water system, they do use the same habitat, and consume similar food items.

How do I know this? A good friend of mine fish for Common Carp in Kingston a lot. It is not a surprise to him when he catches Lake Sturgeon while carp fishing, especially if he fish during the spring or fall, or overnight in the summer. You can find Sturgeon on muddy flats where Carp prefers, and you can also find Carp on gravel/cobbly/rocky deep holes where Sturgeon prefers.

I don't make statement without something to justify the statement.

[Habs]

Yes...I have already stated that.

"* Yes, I do realize that Common Carp not only feed on the bottom, but the main concern with them includes uprooting aquatic habitat, which is the real detrimental effect they have on the ecosystem. But, for argument sake, they do fulfill similar role as Lake Sturgeon."

As for carp using different habitat, preferred food, water temps...etc...it depend on which area you are fishing for carp. On the St. Lawrence, it is not uncommon to be fishing for carp and catch a Lake Sturgeon incidentally. On the flip side, it is also very common to be fishing for Lake Sturgeon and catch Common Carp. So depending on the water system, they do use the same habitat, and consume similar food items.

How do I know this? A good friend of mine fish for Common Carp in Kingston a lot. It is not a surprise to him when he catches Lake Sturgeon while carp fishing, especially if he fish during the spring or fall, or overnight in the summer. You can find Sturgeon on muddy flats where Carp prefers, and you can also find Carp on gravel/cobbly/rocky deep holes where Sturgeon prefers.

I don't make statement without something to justify the statement.

Then please explain how you believe that an omnivorous invasive species, that can tolerate (and even prefer) VERY warm water, that can reproduce 2 or 3 times annually, reach sexual maturity in a few years, consumes as much as one third it's body weight DAILY and renders it's environment almost inhabitable to other fishes "fulfill similar role" (please add the required "a" in that statement) as the sturgeon.
The lake sturgeon prefers and requires cooler more oxygenated water, are almost completely carnivorous, reach sexual maturity in 2 or 3 decades and might spawn every 4 years or so. They have survived in their native ecosystems for tens of millions of years until we decided to value their eggs, quickly making some sturgeon pound for pound the most valuable species fished for commercially. Not surprisingly, most species are now critically endangered.

It is against the law in some parts of the world to release even a common carp back alive. The threat these species pose on native ecosystems cannot be understated. Comparing them in any way to the sturgeon is a mistake.
Your friend catches sturgeon incidentally while fishing carp? Not a huge surprise there, but I'm not sure how that means they "fulfill similar role". Have you caught a smallmouth walleye fishing? A drum trout fishing? A walleye muskie fishing? These fish may occasionally share similar habitats but they play very different roles in the ecosystem.
The barriers that failed in the Chicago Ship and Sanitary Canal will result in even more invasive carp species into the Great Lakes. Please research the impact carp has had on our ecosystems, and what will likely happen when these new threats establish themselves here in North American waters.
Enjoy the carp fishing adventures with your buddy. And let us know when we remove native sturgeon species from the endangered list.

[intothedeep]

All valid points and I agree with all of them actually. I like devil's advocates.

So if that is the case, if we altered an environment badly enough (Great Lakes with Zebra Mussel infestation), and now a biological control is available (Round Goby), with an additional bonus that this biological control also add to the food chain (predator being smallmouth bass, walleye, freshwater drum, and lake whitefish), then should be kill Round Goby indiscriminantly in lakes and rivers where they are already well established? (Because, anglers like to kid themselves and think that the dozen they kill actually has an impact on the millions that are already breeding in the Great Lakes)

If a stormwater pond, those that are now very commonly established in residential complexes are eutrophic and polluted with residential waste (car washing soap, road salt, antifreeze, fertilizers, pesticides), and common carp and goldfish happened to be in these ponds when nothing else can really survive, should anglers be indiscriminantly killing these "invasive" species? Should anglers push for removal of these "pest" and stocking of "sportfish" when sportfish cannot survive such harsh conditions?

When common carp has been established in the Great Lakes for so long, and they are reproducing successfully while providing great sport, then at which point do we consider them as "native" and no longer "invasive"? I'm mirroring your point regarding Brown Trout, Rainbow Trout and Pacific Salmon. Why do I focus on Common Carp? Once upon a time, Lake Ontario was a great producer of Lake Sturgeon, a fish that was extremely great in number until overfishing wiped them out. They are bottom feeders just like Common Carp. Now that Lake Sturgeon are gone, Common Carp can be seen as replacing this void of bottom feeders. So if you argue that Brown Trout fulfill a niche that Atlantic Salmon can no longer satisfy, then I argue that Common Carp fulfill a niche that Lake Sturgeon no longer satisfy. So can we stop considering Common Carp as an "invasive" and start calling them native?

* Yes, I do realize that Common Carp not only feed on the bottom, but the main concern with them includes uprooting aquatic habitat, which is the real detrimental effect they have on the ecosystem. But, for argument sake, they do fulfill similar role as Lake Sturgeon.

If human made a lake barren and restock a species that our actions had wiped out, then it is a reestablishment effort (Atlantic Salmon is a prime example of such effort...but we won't argue whether this effort is worthwhile or not). It is very different from introducing a species to a "barren" lake that formerly does not have such species. The MNR has, in the past and still to some degree currently, sought to create "new and additional fishing opportunities" by stocking sportfish in new locations where they do not occur historically.

If species spread naturally, as in your example that birds or current carry them around, then how is it different that an ocean crossing tanker, carrying basalt water from the Black Sea with some Zebra Mussel embryo is more detrimental than a piece of driftwood that has Zebra Mussel attached, surviving the long and miraculous journey across the Atlantic and eventually drifted into the St. Lawrence River, where the mussels can then be established and eventually spread into the Great Lakes? (I know the difference...it is a time and probability question...but for argument sake, in a philosophical way and not necessarily a practical way...let's think about it a little). Yes, the establishment of a new species in a location separated at such great distance is very remote, but there are real examples of amphibians, reptiles, fish and even mammals that have crossed oceans, adapted and eventually evolved into new species on islands separated by great bodies of water.

I don't expect answers...but just points I like to propose for people to think about.

Yes, wildlife and resource management is not an easy thing.

Yeah lots to think about... Lol

I agree with you on the killing of invasives, it's pointless and useless, unless you get the only one in the lake, which has happened. I believe a pike was caught in rice lake some decades ago and there aren't any to this day... At least I hope not!

I used to kill some fish beyond what I harvested to eat, crappie on Scugog for example to help the eyes, but it's pointless IMO in a big lake...

Gobies too, I heard the MNR killed a section of Perferlaw River to try and control them and coulndt. Gobies are here to stay, and might even be a positive. Carp too, I consider them native, just hope people don't dump them in northern lakes or we get those other types from the USA.

[Habs]

I agree with you on the killing of invasives, it's pointless and useless, unless you get the only one in the lake, which has happened.

LOL. Please provide an example of this.

[tweedwolfscream]

LOL. Please provide an example of this.

Huh? He provided an example in the very next sentence...

I agree with you on the killing of invasives, it's pointless and useless, unless you get the only one in the lake, which has happened. I believe a pike was caught in rice lake some decades ago and there aren't any to this day... At least I hope not!

[Habs]

He's probably right. The Trent-Severn fish stop right at Hastings.