Why Does Everyone Hate Invasives?

Okay, here's a tough one (I think). All fish got to their natural range by being distributed by various natural means from their points of origin; they expanded their range. If a fish's natural range appears to be expanding naturally, is this natural occurrence acceptable, or are they considered to be invasive in their expanded range? On the other hand, how do you know whether the range expansion is due to natural means, or human intervention?

Questions like this make my head hurt. You realize this is going to start a big fight, don't you?

Hey - that Paris Hilton, she's really something, huh?

Okay, here's a tough one (I think). All fish got to their natural range by being distributed by various natural means from their points of origin; they expanded their range. If a fish's natural range appears to be expanding naturally, is this natural occurrence acceptable, or are they considered to be invasive in their expanded range? On the other hand, how do you know whether the range expansion is due to natural means, or human intervention?

Umm. that is not really a tough question...

If a fish can naturally (that means without Human interference in the form of stocking) move to an adjacent body of water then this is called natural distribution.. Floods cause fish to establish in different areas, Glaciers melting cause fish to establish in different areas...Fish will move into and adapt to previously unoccupied environments if pathways exist and favorable conditions make the migration to a new area possible.

Natural Range expansion is really quite obvious in most cases as it is never very far very quick...Largemouth bass in California is not Natural range expansion nor is it always invasive but it is an Exotic introduction..Orange spotted sunfish moving from Lake Erie to Lake Huron is likely natural and is neither Exotic nor invasive as the fish has no impact on the established ecosystem or biodiversity...

Just to clarify since this word invasive seems to not be well understood..
An invasive species is an organism that is so reproductively successful and aggressive that it can dominate an area, often to the point of becoming a monoculture. It interferes seriously with the natural functioning and diversity of the system where it becomes established. An understanding of this definition is needed when discussing this issue especially amongst ourselves.. This is one of a few definitions but is the best one IMHO...

The argument can (and has) been made that human-facilitated range expansion is simply a subset of "natural" range expansion, since humans are a part of nature.

Semantics aside, does it really matter in a hypothetical scenario whether nature put it there or man put it there, if the effect is the same?

The argument can (and has) been made that human-facilitated range expansion is simply a subset of "natural" range expansion, since humans are a part of nature.

I would buy that if humans acted as if they where part of nature..What I generally see is a species obsessed with removing it's self as far from nature as it can. I see a species determined to mold and adjust everything on terms other than that of 'natural'..Human influence in natural systems is generally not one of living with it but to utilize it for selfish personal gain and exploitation.

I do not buy that human culture and activity generally works with the natural world or is a part of it..

In my personal opinion we are the worst invasive animal on this planet and likely will be the total death of this whole place..I however refuse to think that the ecologically ignorant herd is all that mankind can offer this planet. We once lived within our means and within the balance of nature and we can again do so. Until then I guess it will just be a very few of us striving to keep that tiny bit of the natural world alive so that others can live to understand the past and see just where their future lies.

I do not buy that human culture and activity generally works with the natural world or is a part of it..

What he said.

I do not buy that human culture and activity generally works with the natural world or is a part of it..

What he said.

I was not trying to re-start this debate. Apologies if you thought I was. We've hashed that one out before; let's not go there again, please.

If a fish can naturally (that means without Human interference in the form of stocking) move to an adjacent body of water then this is called natural distribution.. Floods cause fish to establish in different areas, Glaciers melting cause fish to establish in different areas...Fish will move into and adapt to previously unoccupied environments if pathways exist and favorable conditions make the migration to a new area possible.

This is exactly what I was getting at. Should we consider these fish migrations acceptable, that their new ranges are natural, and that they should be considered native in their expanded ranges, possibly even conserved? Or should we be working to prevent these migrations, and eradicate them in their expanded ranges, treating them like exotics?

This is exactly what I was getting at. Should we consider these fish migrations acceptable, that their new ranges are natural, and that they should be considered native in their expanded ranges, possibly even conserved? Or should we be working to prevent these migrations, and eradicate them in their expanded ranges, treating them like exotics?

I'm really not understanding you..Why would anyone consider a natural range expansion as invasive or exotic??? Why would there need to be controls (eradication, prevention, etc..) in place for this if it is not an invasive issue.

Should we consider these fish migrations acceptable, that their new ranges are natural, and that they should be considered native in their expanded ranges, possibly even conserved? Or should we be working to prevent these migrations, and eradicate them in their expanded ranges, treating them like exotics?

I don't think that this quasi-religious/philosophical approach to natural resource management is particularly useful. Does it really matter if we deem something natural or unnatural? It's all semantics anyway. I don't really care about the particulars of humanity's relationship with nature. What I do care about is if I will be able to eat the fish out of Lake Michigan without getting sick (if there happen to be any fish other than round gobies left in 10 years).

What we should be concerned with is whether or not a particular organism is interfering with the proper functioning of a given ecosystem. Common sense will tell you that moving Fish A across the Atlantic Ocean and dumping it in a river is probably going to cause more ecological problems than Fish B expanding its range 30 miles in a given direction. I think it's pretty clear in the cases where we've screwed up and introduced exotic invaders. Our time and resources are better spent mitigating the impact of our past mistakes and preventing new ones.

I know I'm going to regret getting involved in this

Orange spotted sunfish moving from Lake Erie to Lake Huron is likely natural and is neither Exotic nor invasive as the fish has no impact on the established ecosystem or biodiversity...

Bzzzzt. The range expansion of the orangespot sunfish into the Great Lakes watershed was facilitated through the connection of the Wabash and Maumee watersheds through the Erie and Wabash Canal.

As well, the genotype that's expanding is probably not the historical genotype that was present in the heavily wooded streams of the Wabash. This species infrequently occured east of Illinois until we stired up all the mud.

So perhaps you should be killing this species and gizzard shad, which were also in low abundances historically?

As for its effects on the established fauna, I agree, it's probably minimal, as with MOST exotics who kinda show up and become naturalized as another player in the game. However, they ARE eating food that pumpkinseed sunfish would have been utilizing as a food source in habitats part of the historical range now too turbid for them to be much more than a patch habitat.

I think something else you should consider are the state of the waterbodies where exotics are invasive (let's please keep in mind that they are two different things). I've yet to see any historically speciose watershed where it's perhaps, say, 50% intact with regard to historical context, have anything resembling an invasion. The places where exotics get invasive are heavily disturbed and continually disturbed with shipping and agriculture. Systems left more intact are resilient to invasions, again, leaving exotic species as just another player in the game.

This goes for asiatic cyprinids, zebra mussels, any of that. Where are all the jumping carp in the St Francis, Black and Meramec Rivers in the Missouri portion? They're in the lower reaches where it's heavily agricultural or severely ubran, but not further up?

I'm even looking into situations where more intact river SEGEMENTS are resilient against invasion with regard to zeebs. That is to say, they're invasive above and below the segment in question, but not where the system more resembles the historical morphology and ecology. They're obviously getting there... Why aren't they running that over? Zeebs always win, right?

If we really want to get serious about managing exotic invasives already present in aquatic environs, we need to start looking at removing the disturbances that facilitate the continued expansion, as it may be. Only then, will it seem the sky has stopped falling.

Now... Spring head habitats with bass and gambusia... That's an entirely different matter.

But in the fertile east... I feel strongly that this should be the first line of defense against invasions.

Todd

I would buy that if humans acted as if they where part of nature..What I generally see is a species obsessed with removing it's self as far from nature as it can. I see a species determined to mold and adjust everything on terms other than that of 'natural'..Human influence in natural systems is generally not one of living with it but to utilize it for selfish personal gain and exploitation.

I do not buy that human culture and activity generally works with the natural world or is a part of it..

In my personal opinion we are the worst invasive animal on this planet and likely will be the total death of this whole place..I however refuse to think that the ecologically ignorant herd is all that mankind can offer this planet. We once lived within our means and within the balance of nature and we can again do so. Until then I guess it will just be a very few of us striving to keep that tiny bit of the natural world alive so that others can live to understand the past and see just where their future lies.

Nothing living on this planet acts in a way that is unselfish. All organisms, if given the opportunity, have reproduce and eaten all of the available food to the point that a population crashes. One small example is; I sampled a small head water stream that had the highest abundance of larval salamanders, they have demolished the macroinvertebrate populations (hardly any identified in two seperate samplings). The larval salamanders will not survive the amount predation that they have been doing.

We are the only species that takes active roles (most of the time not enough) in restoring the damages that they have caused or even chose to make changes in the lifestyles that they live, we are the only ones given the ability to chose to change. Like most species, most people would not willfully chose to do irreversable damages to their environment. They simply have lived their lives like they have for thousands of years. Most people are just worried about keeping up with the bills and putting food on the table in the cheapest way that they can. Do I believe that we should do better, you bet. But I guess that I am just not down on the human race, I just think that an effort that is not in your face, is shown to beprofitable, with patience, and perserverance and is positive needs to be given to people. That is one turn off that some people have with relating to "environmentalists" is that they are some time made to feel that they are horrible. That is why we join organizations (like NANFA), that is why we set examples, that is why we take active roles in teaching. I know that I have learned over the years to change ways of incorrect behavior. When I was first working on cars my dad had me dump the old oil in between the cracks of the porch. We did not think anything of it. As I learned what that oil does to ground water, I changed my behavior and recycle my oil. How many in this forum did not know that you should not dump aquarium plants or animals in streams?
Sorry about drifting from the main topic.

Matthew

the proper functioning of a given ecosystem.

Who's to say what the "proper" functioning of a given ecosystem is, escepcially given the narrow temporal slice we are looking at? It makes no more sense than saying that the earth's current temperature and climate is the proper and ideal one, and that any changes plus or minus are an indication of impending catastrophe.

The one constant in nature is that things change. This particular window in time does not yield a snapshot of the "ideal" ecosystem, whatever that is. Nor did it 100 years ago, or 1000, etc.

You guys claim humans are the problem, but you define everything from a human point of view, which is itself an artificial (read "unnatural") construct.

Now, if the earth were a charred cinder, then that would be a shame.

We once lived within our means and within the balance of nature

I don't understand what "within our means" means, or what the balance of nature is that we no longer live within? What I am certain of is that at one time there was a standard of living that none here would care to immerse themselves in. I mean, c'mon, how many of you stay at a hotel when you attend NANFA conventions, as opposed to camping? I know - the bugs, the heat, the hard ground, and hey- it might rain!

Perhaps you refer to the myth of the noble savage? It really is a myth. Don't let "Dances with Wolves" fool you.

Is human population the problem? Could be... you guys who study population dynamics, does it appear that the current ecosystem has reached it's human carrying capacity, based on population curves? And does a system in which a species has reached its carrying capacity indicate a system which is somehow broken? Whether a stream is "degraded" depends on whether you're a trout or a green sunfish, doesn't it?

know that I have learned over the years to change ways of incorrect behavior. When I was first working on cars my dad had me dump the old oil in between the cracks of the porch. We did not think anything of it.

My dad had me dump it down the STORM SEWER!

And no, I'm not trying to one up Matthew

Todd

My dad had me dump it down the STORM SEWER!

And no, I'm not trying to one up Matthew

Todd

No problem. I'm sure that we all have stories, and I am sure that some are way worse than you or me.

My dad had me dump it down the STORM SEWER!

Funny, we had this same conversation at the office today at lunchtime. My dad used to dump it down the storm sewer too. Until I figured out where it went. When I told him it came out a pipe into a stream over the hill, he stopped doing it. You can't really blame him. He thought it was going to a wastewater treatment plant. He grew up in the city, where they have combined sewers (the storm sewer does go to the wastewater treatment plant). The combined sewer problem is a problem that is gradually being corrected, but it will take a long time; billions of dollars in infrastructure are involved. We don't have combined sewers in the suburbs. Really, the terminology is also confusing. "Storm sewer" makes it sound like it conveys sewage to a treatment plant. They really should be called storm inlets.

This problem is now being curbed in our area by painting warnings on the curb next to the storm inlets. The warnings are a fish and text saying something like "do not dump, drains to river".

Is human population the problem? Could be... you guys who study population dynamics, does it appear that the current ecosystem has reached it's human carrying capacity, based on population curves? And does a system in which a species has reached its carrying capacity indicate a system which is somehow broken? Whether a stream is "degraded" depends on whether you're a trout or a green sunfish, doesn't it?

As you know, human population is currently growing in an exponential fashion, meaning that the line of population vs. time continues to go up at a steep rate with no indication of leveling off. So we haven't reach a carrying capacity, and anyway who knows what that capacity is? I would say that it's about 500 million , but that's pure opinion.

And I know that you know that a species at carrying capacity doesn't mean the system is broken so we can drop that charade. "Degraded" is a community concept, and usually implies human agency in the change. If you and several thousand of your pals poop in the stream I think neither trout nor green sunfish are favorably impressed.

Bzzzzt. The range expansion of the orangespot sunfish into the Great Lakes watershed was facilitated through the connection of the Wabash and Maumee watersheds through the Erie and Wabash Canal.

I'm actually aware of this and understand it is a bad example and should have used a different one. I likely would have if this thread was about specific scientific details regarding such matters.. If you read the post though you would also know that OSS are not found in Lake Huron which is a bit bigger mistake in wording should one care to know it....I just pulled an example to use as a hypothetical example... did not have a reference behind it nor did it need one. I agree wording should have explained this further.

I don't understand what "within our means" means, or what the balance of nature is that we no longer live within? What I am certain of is that at one time there was a standard of living that none here would care to immerse themselves in. I mean, c'mon, how many of you stay at a hotel when you attend NANFA conventions, as opposed to camping? I know - the bugs, the heat, the hard ground, and hey- it might rain!

Perhaps you refer to the myth of the noble savage? It really is a myth. Don't let "Dances with Wolves" fool you.

Don't start me down that road..... really....You want to know My idea of camping ask Uland. Yeah I have a cell phone a computer and a Kalashnikov but I actively will flintknap a deer point for a dart, start a fire with a hand drill and collect various seeds, plants and food items myself also. In fact about 40% of my diet is naturally occuring goods harvested responsibly from nature...This has nothing to do with whatever this 'noble savage' myth is.Or some pie in the sky protein deficient ideas of 'loving mother earth'..I do think that humans can exploit yet preserve what we find in nature. This is not the current model of human thinking. The current model is consume and lay waste to everything....This is not balance with what we know are ecologic principles that apply to all other species or to ecosystem models. We stand far outside of the general laws of ecology that apply to all other species..

Under the definition of invasive, Humans are by far the worst invasive species of all..They have layed waste to everything before them to create a perfect monoculture of just themselves and those things useful to them. The natural world and it's processes in modern times are things to be conquered and overcome...To in essence be domesticated.

While some may disagree I find this Unnatural and not healthy.. I'm not some greenie, twig eating, fuzzy lover...
I get climate change, I get ecologic principals, I get that humans are part of nature...What I do not get and will not accept is that Humans are so very ecologically ignorant that all they seem to do is continue a trend of devaluation when it comes to biodiversity and balanced ecologic principles.

On another note: Forums or e-mail lists generally suck for these types of discussions... A better alternative that conveys ones true feelings and ideas is better accomplished over a nice good campfire or a chat at a bar..Face to face where space is not a limit and interpretation of language is not left to ones imagination but expressed openly and in real time....

I likely would have if this thread was about specific scientific details regarding such matters..

As opposed to using what? Opinions? <evil grin>

Todd

As opposed to using what? Opinions? <evil grin>

Todd

What do you see this thread as being??? a dissertation on Exotic and invasive species???
that was a lost cause awhile back...Whats the point at this time to use anything but opinions...

It would be cool to have a more specific discussion about the noticed observations that us in the field have seen regarding Invasive species (anecdotally and researched) Thats not this thread though...Care to start up something new Todd feel free....Or I will later... which ever .....

On another note: Forums or e-mail lists generally suck for these types of discussions... A better alternative that conveys ones true feelings and ideas is better accomplished over a nice good campfire or a chat at a bar..Face to face where space is not a limit and interpretation of language is not left to ones imagination but expressed openly and in real time....

100% agreement on that one! Whatever happened to your Detroit River research project? I was planning on setting aside at least a weekend of my summer (if not more) on that. A perfect opportunity for a friendly debate. Is the project still in the works?