Invasive Species
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21-04-2013, 06:28 AM
Invasive Species
In a few minutes I'm off to scout some new reefs for an upcoming Lionfish Derby.

For those who aren't aware, Lionfish Pterois volitans and Pterois miles are an Indo-Pacific species that turned up in the Western Atlantic in the early 1990's. Since then they have dispersed throughout the Caribbean and Atlantic seaboard.

[attachment=1333]

http://fl.biology.usgs.gov/lionfish_prog...ssion.html

They are voracious, omnivorous, covered in venemous spines and have no known predators here. They release masses of eggs, 30,000 strong, every 4-6 days and these egg rafts are encapsulated by a foul tasting gelatenous mass that float to the surface and are dispersed by the currents.

In the Keys we hold several derbies a year and I always go into the water with a pole spear in case I see one. So far I've removed/culled/killed nearly 500 in the last three years since they showed up here.

Because they were introduced by humans, (we think that the aquarium trade is responsible for bringing them to Miami and then someone released them into the ocean after the bastards ate the rest of the fish in their aquarium), we tend to think of invasive species as, well, invasive and exotic.

I have argued that we, humans, are not outside the natural world, therefore when we introduce species to new environments it is simply nature finding a way. Why we feel the need to preserve the status quo is misdirected.

What do you all think?

http://www.reef.org/exotics

"Ocean: A body of water occupying about two-thirds of a world made for man - who has no gills.” ~ Ambrose Bierce
“I am quite sure now that often, very often, in matters concerning religion and politics a man's reasoning powers are not above the monkey's." - Mark Twain in Eruption
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21-04-2013, 06:36 AM
RE: Invasive Species
(21-04-2013 06:28 AM)Full Circle Wrote:  So far I've removed/culled/killed nearly 500 in the last three years since they showed up here.

What do you all think?
I can only speak for myself, but I think that makes you a bloody mass murderer Dodgy

Did you know that a species of jellyfish (that you guys, brought our way!) nearly took out all the life in our Black Sea?

"A population of unassuming comb jellyfish was sucked into the ballast of a U.S. tanker and shipped halfway around the world in 1993, where it was unceremoniously dumped into the Black Sea when the tanker discharged its ballast water.

This seemingly innocuous event caused one of the most alarming species invasions in European history. At their peak in the mid-1990s, the comb jelly invaders made up 90 percent of living organisms in the Black Sea — the sheer weight of the invasive population exceeded the weight of the world’s entire fish catch. The jellyfish destroyed the Black Sea’s commercial fishing industry and cost thousands of jobs."

"E se non passa la tristezza con altri occhi la guarderò."
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21-04-2013, 08:06 AM
RE: Invasive Species
(21-04-2013 06:28 AM)Full Circle Wrote:  I have argued that we, humans, are not outside the natural world, therefore when we introduce species to new environments it is simply nature finding a way. Why we feel the need to preserve the status quo is misdirected.

What do you all think?

I think religion acts like n invasive species, but then again that's man made as well.


The problem with invasive species is only really a problem if there is no predator to keep them in check. There's some stories about speculation that there might be some natural predators that are willing to consume the lionfish:

http://www.news-press.com/article/201205...-lionfish-
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21-04-2013, 09:09 AM
RE: Invasive Species
When you're done spearing lion fish in the keys, get your salt ready. You have an invasion of giant land snails.

[Image: images?q=tbn:ANd9GcSk5pbIutM2tbQK7CNOu_M...xwD-4uX2Aw]

After that, get your machete and head down to the Everglades to kill a 16-ft Burmese Python.

[Image: python-florida-everglades-web.jpg]

"IN THRUST WE TRUST"

"We were conservative Jews and that meant we obeyed God's Commandments until His rules became a royal pain in the ass."

- Joel Chastnoff, The 188th Crybaby Brigade
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21-04-2013, 09:14 AM
RE: Invasive Species
I agree with you that its all part of nature but the reason we humans like to preserve the status quo is because we like the status quo.

Vosur, Anjele, Hanoff.....have you learned nothing in my absence?
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21-04-2013, 09:24 AM
RE: Invasive Species
Even if we consider human activity to be a natural means of spreading species, that doesn't mean we should accept the results. The reason we tend to like the status quo is because it is beneficial to us. If we maintain the ecosystem how it has been for centuries, then we know it can be stable and productive.

When we introduce invasives, we potentially upset the balance and become ignorant of the future. We may no longer be able to predict how many bunnies there will be come hunting season, how much water will be in the rivers, how much food the livestock will have, how many fish there should be...

And even worse, we do not know what will happen to the ecosystem long-term. It could change in a positive way such as creating an ecosystem that is more resilient to human activity. Or it could remove certain kinds of animals and plants permanently. Maybe the fish that was killed off was edible, but the one that replaced it wasn't. Or there are no fish in a lake now. Invasives can potentially destroy valuable resources and wipe out keystone species, causing massive economic losses and ecological destruction.

As much as humans can adapt to changes, the potential for catastrophic change that we cannot adapt to exists. Most places do not have the ability to adapt quickly. If the salmon population crashes in America, life goes on. If the fish population pretty much anywhere in sub-Saharan Africa crashes, hundreds of thousands lose work and go hungry, and local economies can collapse.

People fear what they do not know, and invasive species make us ignorant of the future.

If something can be destroyed by the truth, it might be worth destroying.

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21-04-2013, 12:00 PM (This post was last modified: 21-04-2013 12:05 PM by Ghost.)
RE: Invasive Species
Hey, Brian.

Quote: I think religion acts like n invasive species, but then again that's man made as well.

That's the most ridiculous thing I've ever heard.

Religion can be an invasive memeplex. Gawd. What do you think? I'm stupid? MY DAD'S NOT A PHONE! DUH!





In all cereal, you just lit my brain on fire. It forced a question in my head. Do memeplexes have predators? My first reaction is that they might. But that really, it's more a selection pressure. But then again, predators should be thought of more as selection pressures than predators. Hmmmmm. Curiouser and curiouser. Further down the rabbit hole I go Cool

Hey, Vera.

Quote: I can only speak for myself, but I think that makes you a bloody mass murderer

As a lover of animals and a vegan, I'm with you in spirit. That being said, despite the fact that it may be futile, slowing the advance of invasives is important.

That jellyfish business is fucked up. Sorry to hear about your troubles. Canada's big collapse was the cod fishery... which will likely never rebound. Ooops.

But the fact that it may never recover underlies what I'm going to say next.

Hey, FC.

If you really want to get a handle on invasives, read THE FUTURE OF LIFE by EO Wilson.

In the book he discusses invasives at length and talks about HIPPO: the big threat to biodiversity.
Habitat loss
Invasive species
Pollution
Population (human overpopulation)
Over-harvesting

Quote:I have argued that we, humans, are not outside the natural world, therefore when we introduce species to new environments it is simply nature finding a way. Why we feel the need to preserve the status quo is misdirected.

What do you all think?

You're absolutely right. We aren't outside the natural world. Therefore, strictly speaking, everything that we do is "natural". Really all that illustrates is that the natural/unnatural dichotomy has little actual value, so we move on.

Whether or not it's nature finding a way isn't so much the issue. Preserving the status quo isn't so much the issue.

The issue is being a bull in a china shop.

Ecosystems are delicately balanced. They remain relatively stable over long periods, experiencing subtle change. That stability is punctuated by short periods of rapid change. That's the punctuated equilibrium theory.

An ecosystem isn't just a heap of parts, it's a system. All of the species in that system co-evolved. The zebra is the zebra in large part because the lion is the lion. So unlike a heap, from which you can yank out parts at will, a system is made up of interdependent parts and ceases to function when you yank them out at random. As an example, yank cigarette butts out of an ashtray and nothing appreciable happens. Pull anything out of your laptop and watch how quickly you break it.

Part of the balance is the population dynamic. Everything eats everything else essentially. The zebras numbers are kept in check by the lion and in turn, the lion's population is kept in check by the supply of zebra. This predator prey relationship over time looks like a sine-cosine wave:

[Image: images?q=tbn:ANd9GcSpyuVrYyvtc1MUj8MNhcr...D6-5KqAQnX]

All species within a system act as a selection pressure on every other species. When they say that something has no natural predator, they mean that there is no selection pressure, so pretty much ALL individuals survive.

When populations grow without restriction, they approach the carrying capacity of the ecosystem.

[Image: fig6_07.gif]

If the population outstrips carrying capacity, it goes into overshoot.

[Image: ecological_overshoot_clip_image001.gif]

So when an invasive comes in and it has no natural predator, it's population skyrockets and very quickly goes into overshoot. It tears through the food supply in short order. When a species goes into overshoot, it's pretty much a guarantee that there will be a resulting catastrophic die-off (and by catastrophic, it is roughly meant in the 90-100% range).

If the catastrophic die-off was the only issue, that would be bad enough. But when this occurs (and this goes back to Vera's example of the Black Sea and my example of the cod fishery) carrying capacity is degraded.

[Image: Overshoot_2.jpg]

Furthermore, in the case of the cod collapse, the near disappearance of the cod opened up a huge niche and seal and squid moved in. Now, even though we've almost entirely eliminated the cod fishery, the cod can't rebound because there's no longer room for them in the ecosystem.

In the case of invasives, if the thing they feed on doesn't have a lot of connections in the ecosystem, then they'll just kill themselves off (like the reindeer on St. Matthew's island - they ate all the moss and died to the individual; almost six thousand in all; most of them dying over a single winter). That's bad for the invasive and it's bad for the species they overwhelm (the moss took forever to regenerate and, if I'm not mistaken, like the cod, never returned to its former level). But it still gets worse. If the species they overwhelm is a keystone species, then the ecosystem will collapse.

A bleached coral reef is a great example.

[Image: coral.jpg]

A collapsed ecosystem is a non-functioning one. None of the species get what they need anymore. There's a catastrophic collapse in ALL of the dependent populations. That's game over time.





So what we need to avoid as humans, is behaviour that leads to the introduction of invasive species that harm or collapse ecosystems.

But I still haven't answered your question. Why is that important?

Because we rely on these ecosystems. They are our life support systems.

Historically, when we've collapsed our regional ecosystems, we've just moved on to greener pastures and left deserts in our wake. This is called hitting the secondary limits to growth.

But there is a primary limit to growth.

Because the biosphere is a system too.

Every time we kill an ecosystem, we yank a part out of the biosphere. If we collapse that, then we make Earth inhospitable to human beings. And then poof, no more us.





It happened to the dinosaurs, it can happen to us.

And it will happen to us. At some point in the future - this century, next century, in a thousand years, a hundred thousand, a million, ten, a hundred, a billion years, whenever - there will be no more humans. 99% of the species that have ever existed on this planet have gone extinct. We will be one of them. The only question is, will it happen because it had to, or will it happen at our hands? And how many other species will we drag down with us?

PS: There have been seven mass extinctions in the last 3.5 billion years of Earth's history. The first six were the oxygen holocaust (which typically is excluded from the list), the Ordovician–Silurian extinction, the Late Devonian extinction, the Permian–Triassic extinction, the Triassic–Jurassic extinction and the Cretaceous–Paleogene extinction. That last one, the Cretaceous-Paleogene, was the one that killed off the dinosaurs sixty five million years ago. In terms of devastation to living species and genera, it was the second worse of all time. The seventh mass extinction? It's happening today. Right now. All around us. It's the Holocene extinction and it's challenging the Cretaceous–Paleogene for the number two spot on the all-time devastation list. What separates the Holocene from the other six is that the Holocene has but a single cause. Human activity. That is to say that human activity is generating the same destructive force as whatever it was that killed off the dinosaurs. I don't think I can downplay the magnitude of that.

Peace and Love and Empathy,

Matt
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22-04-2013, 07:08 PM
RE: Invasive Species
(21-04-2013 08:06 AM)BryanS Wrote:  The problem with invasive species is only really a problem if there is no predator to keep them in check. There's some stories about speculation that there might be some natural predators that are willing to consume the lionfish:

http://www.news-press.com/article/201205...-lionfish-

Interesting. I quote the article:

“People suspect that goliath grouper would eat lionfish,” said Michael Parsons, professor of marine science at FGCU. “We went out to Edison Reef and Doc Kline Barge Tuesday to look for lionfish. We didn’t see any, but we did see plenty of goliaths.

“The thought was maybe the goliaths are eating the lionfish. It’s a question of whether they’re really doing it.”

It is my experience that Goliaths do not take them alive. On a steel barge we know of there is a resident Goliath and over 40 Lionfish living there. Well, the Lionfish are gone now Cool but not because of the Goliath.

"Ocean: A body of water occupying about two-thirds of a world made for man - who has no gills.” ~ Ambrose Bierce
“I am quite sure now that often, very often, in matters concerning religion and politics a man's reasoning powers are not above the monkey's." - Mark Twain in Eruption
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22-04-2013, 07:14 PM
RE: Invasive Species
(21-04-2013 09:09 AM)Carlo_The_Bugsmasher_Driver Wrote:  When you're done spearing lion fish in the keys, get your salt ready. You have an invasion of giant land snails.

After that, get your machete and head down to the Everglades to kill a 16-ft Burmese Python.

South Florida has more invasive species than you can shake a stick at. According to Fish and Wildlife the Raccoon, Possum, Whie-tail Deer and Bobcat population in the everglades is down over 90% because of the pythons!

http://www.npr.org/2012/01/31/146124073/...ng-animals

"Ocean: A body of water occupying about two-thirds of a world made for man - who has no gills.” ~ Ambrose Bierce
“I am quite sure now that often, very often, in matters concerning religion and politics a man's reasoning powers are not above the monkey's." - Mark Twain in Eruption
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22-04-2013, 07:35 PM
RE: Invasive Species
Ghost - First of all great graphs. I agree wholeheartedly with your assertion that when invasives destroy an existing cog in an ecosystem that ecosystem collapses.

The Lionfish story has been a unique one in this part of the world in that for the first time a fish has not only adapted but thrived. The Bahamas have seen their fisheries and reef fish populations collapse almost entirely due to the Lionfish and here in the Keys we're trying to avoid the same fate.

After three years of hunting these fish I can almost always identify where I will find them even though they like to hide during the day. I just look for schooling juvenile fish on any coral head there they will be until the food supply is gone then they move on to the next coral head. They eat cleaner species that larger species rely on for removal of parasites, they eat juvenilles by the dozen, they eat cleaner shrimp, crabs and juvenile lobster.

This year we had a poor lobster and crab harvest, not known how much was due to the Lionfish BUT my neighbors who are commercial fishermen have anecdotal evidence that Lionfish are partially to blame. They are bringing up traps and when there are Lionfish inside there are few lobsters.

Anyway, tomorrow we will reconnoiter a few new spots and on Wendsday we'll participate in the Derby. Our only hope so far for controlling these fish is to create a commercial demand for them, their meat is very delicate and tastes very good. Only problem is they don't hit lures so they have to be speared or brought up in traps.

"Ocean: A body of water occupying about two-thirds of a world made for man - who has no gills.” ~ Ambrose Bierce
“I am quite sure now that often, very often, in matters concerning religion and politics a man's reasoning powers are not above the monkey's." - Mark Twain in Eruption
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