Exotic species in San Francisco Bay:

[Ninong]

Interesting article in today's SF Chronicle for those of us who like to keep up on this situation.

[Samper]

Very interesting indeed...I would have never thought that discharged water from ships to be a problem related to invasive species

[Ninong]

Very interesting indeed...I would have never thought that discharged water from ships to be a problem related to invasive species

It's the most common method of transport for a wide variety of species, especially those with pelagic larval stages. It's also a method of transport for nuisance algae.

The notorious Stuttgart aquarium mutant strain of Caulerpa taxifolia that was accidentally released by the Monaco Aquarium into the Mediterranean ended up off the south-eastern coast of Australia and off the coast of San Diego. In the case of the San Diego infestation, that is thought to have been an accidental release from a marine aquarium but the infestation in Australia may have come from ship ballast water. Caulerpa spreads by fragmentation, so it's possible that tiny fragments could have been in the ballast water. This particular strain of C. taxifolia is extremely invasive, wiping out all indigenous benthic life whereever it spreads. It is quite capable of spreading all across the west coast of the United States, all the way up to British Columbia. And, of course, it could easily spread south from San Diego. It has devastated local fisheries in the Mediterranean by replacing native flora that the native fauna depended upon.

[Samper]

I seem to remember reading somewhere that problems like this occured when the panama canal was opened up too....we're destroying the balance.

[Ninong]

I seem to remember reading somewhere that problems like this occured when the panama canal was opened up too....we're destroying the balance.

Don't forget the Suez canal.

In the case of the Suez canal, species that migrated north into the Mediterranean are called Lessepsian species. The reason I know that is because when I was a kid, the mayor of New Orleans was DeLesseps S. Morrison. He was named for the guy who engineered the Suez canal, as are the species that migrated into the Mediterranean thanks to that canal.

[Ninong]

Here's another interesting photo-filled article about the exotic organisms in SF Bay.

[marxsman]

thats pretty interesting. An Asian clam was introduced in Colorado and is now a problem. It was introduced about 1998 in Pueblo Reservoir.

[icemark]

I personally don't get the concern.

In most cases, a preditor has evolved or came in to solve an expansive animal.

So, the bay is down on plankton right now... it won't be long before it re-stabilizes in another matter. For example the Asian Clam...The "invasive" & "exotic" oyster drill now uses the Asian Clam as its primary food source.

One of the worst things we can do (as a species) to the enviroment is to try and keep it static. Just look at the history and mis-management of Yellowstone park if you don't believe me. The planet will re-stabilize itself, just like our tanks do.

[greenbean36191]

The concern is the loss of diversity and the economic impact.

By definition invasive species don't have any effective predators. The oyster drills do eat the clams but they don't control them, hence the huge flats with nothing but clams. The monopolization of the food and territory puts a huge strain on competing native species (which do have limiting factors on their populations). As a result any species further up the food chain are affected as well, especially specialized feeders. Unfortunately, most people think like yourself and it's not a problem until you can no longer get your favorite seafood.

Invasive species do their damage much more quickly than predators evolve or come in to control them. There have been very few example of that ever happening.

I'm sure even conservatives can appreciate the economic impact of spending millions of dollars a year to clean exotic fouling organisms out of factory water intakes or off of ships' hulls. Generally shutting down fisheries due to the decline of catches isn't a great thing either.

I'm not sure how Yellowstone is an example of why we shouldn't care since it's probably one of the better examples of what carelessness does. It was our careless attitude towards the environment that led to hunting wolves to extinction, which led to an increase in elk and in turn a decline in vegetation. After we realized our error and re-introduced the wolves the elk population started to go back down and the vegetation started to return.

[icemark]

See the loss of diversity and economic impact are short-term results.

If we continue to manage for short-term results we will always have problems.

Yellowstone again is a classic example of short-term thinking. Kill the wolves because they were a threat to the diversity (and man) in the environment. Whoops no predators, prey runs amok.

Forest management is the same way. Look at the bark beetle problems in the Rockies. Prevent leaning of trees/put out forest fires ASAP. Leads to too much tree growth, leads to diseased trees, leads to beetle infestation, leads dead trees, leads to even bigger more damaging forest fires, leads to massive budgets needed to manage forest fires that shouldn't have happened on such a scale in the first place. Each step, a short term solution to the previous problem, and much more costly in the long term!

We already changed the environment of the Bay. Like it or not. It will take time to re-stabilize, but it probably will eventually re-stabilize as new predators and prey either evolve or migrate in. Going back in now with money, chemicals and controls will prevent that re-stabilization from returning sooner and as we spend even more money, further hurting the economic side of the equation.

Lets look at The Green Crab... considered a invasive speices that was originally thought to overrun the commercialized Dungress crabs...all the panic about it... and what finally happened... well to quote the article:

Scientists think that the crab, an accomplished predator, is also serving as prey for Dungeness crabs, leopard sharks, bat rays and sturgeon. In other words, while green crabs have secured a niche in Northern California's estuaries, they aren't overwhelming the systems as originally feared

But my biggest point is why should the bay remain static? The world around us is always in motion, Changing, evolving. Why do we think that we as a species should control that? As mentioned in that article Japan has the right idea on this. They don't think that extra/invasive/alien spieces being brought in is nessasarly a bad thing

It can be summed up with the last paragraphs of that article:

Until recently, Japanese biologists haven't expressed much concern about exotic species, and even now they aren't exactly alarmed.

"My impression is that Japanese scientists don't see it as a problem to the degree that we do," Cohen said. "Here, we're concerned about preserving natural systems. There, the emphasis is more about the support of commercial fisheries. They're concerned about maintaining species that can be eaten."

See my biggest concern would be that short term thinking and spending to solve the issue. The loss of diversity, the minor econimic concerns... these are simply short term issues. Left to its own means nature will come up with its own solution... something that it has been doing for millions of years. Man trying to keep something static or what suits him right now is just a mistake in monumental proportions. We already screwed it up, but in no means should we think we are better than nature in fixing it, and try and do it ourselves.

[greenbean36191]

You know, you're right. I'm going to go rape the reef since the impact of humans on the environment is only short term. We should stop caring about the health of the organisms we depend on and think about the long term. We'll all be dead by then so what does it matter anyway, right?

[BubbaWPB]

I find it sort of silly that we as humans can invade and distroy an environment, and that's just fine, but it's a problem if clams do the same thing.... just a rhetorical thought....

[Ninong]

I find it sort of silly that we as humans can invade and distroy an environment, and that's just fine...

Really? You sound like a Republican!

... but it's a problem if clams do the same thing....

Ah, but the clams didn't do it, did they? We did it! It wasn't their fault. With all our subduing and having dominion over everything we forgot the part about replenishing.

[BubbaWPB]

Well, it must be my French "cynicism gene" acting up... I think if environmentalists were really concerned about the environment, they would all live in high rise apartments in the concrete jungle where the environment has been ruined for centuries already, and avoid the spread of humanity into "untamed" areas.... but NNNOOOOO!.... they keep deluding themselves by building so-called "green" buildings in wilderness areas and think it's cool.

Seriously, I do think the foreign species "invasion" is a real concern... as well as the human species's cancerous spread.... we've got pythons invading our neighborhoods here in south Florida, now that they are breeding wildly in the Everglades...

[icemark]

You know, you're right. I'm going to go rape the reef since the impact of humans on the environment is only short term. We should stop caring about the health of the organisms we depend on and think about the long term. We'll all be dead by then so what does it matter anyway, right?

No you are missing the point.

What would have happened if the invasive species that colonized North America in just about every age of the planet never happened???

Say you would be some omnipotent being, that was watching out over the world, and you see these strange animals migrating down the Aleutian land bridge..., and you stepped back and said, "OH NO" we can't have these Herbivores coming down to North America. They will eat everything. They will strip the environment and kill the area. Then they will be followed by predators like fleas on dogs... oh no, then the predators will eat all the animals already in North America. What a mess… the whole continent will be destroyed just like San Fran bay might be if you listened to the doomsayers.

So you stop the migration. You stop the dinosaurs from coming to America; you stop the Tyrannosaurs, the duckbills, and the rest.

But wait 100,000 years and it is starting again, dammit. Look now there are those damm woolly mammoths and saber toothed cats and those stupid primates...all coming into North America... why they will kill all the food for those tiny antelope that are all over… oh no they will also bring fleas… Better stop the Indians, and Mammoths…

Wait... I know something in the modern age of Man... The brown snail...

Oh no, man brought the Brown snail over to America... There are billions and billions of plants that it will devour, denuding the whole continent. Did you know the average garden snail is not native to North America... boy it sure causes havoc... it eats my beans before I am ready to pick them. We should eliminate that damm brown snail... after all it is an invasive species as well. But funny... the brown snail, the Mammoth, the saber toothed cat.. all migrated in (by themselves, or on the back of Man) and the environment compensated and thrived.

Would you change the environment or did they??? They were just doing what animals do. These "invasive" species called out in San Fran Bay are no different than those Tyrannosaurs, or Mammoths. These bay animals just migrated in, in the ballasts of our ships. No different than across a land bridge. The world survived just fine, as in nature, change is good.

Only man is stupid and foolish enough to think that he can control the world and keep it static. I would think reef keepers with the experience of our minicosms, reef keepers above all others would see this. Nothing in a reef is ever 100% static. Something is always growing and something is always dieing. Ebb and Flow. We mix species from different Oceans, from different seas... Sometimes on purpose… sometimes on accident; and they all figure a way to get along, even if it means occasionally something must die.

[greenbean36191]

It amazes me what people can convince themselves of if it makes them feel better.

First of all, lets clear up what an invasive species is. It is not just any introduced species. As you have pointed out many introduced species do not end up displacing native species or destroying habitat. Those are simply, exotic, alien, introduced, non-native, or whatever you want to call them. Invasive species are species that have an unfair competitive advantage over native species. By definition they always have a negative impact on their new environment, be it habitat destruction, monopolization of food or space, predation on native species, introduction of diseases which natives have no immunity for, etc. Their presence leads to decreased diversity and sometimes local or complete extinction of native species.

These bay animals just migrated in, in the ballasts of our ships. No different than across a land bridge.

Wrong. Natural migration and introduction of invasive species are far from being ecologically equivalent. When animals migrate naturally they radiate out to adjacent habitats and their predators almost invariably follow since they tend to have similar environmental requirements. They are subject to essentially the same limiting factors as in their old habitat. As a result the incoming species don't have much of an un unfair advantage and diversity usually goes up slightly or stays about the same.

When we introduce invasive species we generally don't bring their natural competition with them. They are essentially unrestricted by predation (that's not saying they have no predators) and can essentially eat and reproduce to the environment's carrying capacity. The native species on the other hand have to not only compete with effective predators, but they also have to compete with the invasive species.

Both do change the ecosystem. One just allows time for other species to adapt to the changes while the other kills off those that aren't already suited to compete.

No one expects the environment to stay stable or species never to go extinct. What some people do hope for is that we will quit forcing it farther from its natural rate of change and to a state of global homogeneity

If I tear down your house eventually someone will build something else there. That's no different to you than if we waited for time and the elements to take their toll and eventually knock it down right?

We mix species from different Oceans, from different seas... Sometimes on purpose… sometimes on accident; and they all figure a way to get along, even if it means occasionally something must die.

If "get along" you mean kill the native species until the invasive is either the only one left or dominant.
I wouldn't call going through a transition like this getting along:

[sihaya]

Icemark- you're arguments are rather niave. I'll concede that human beings are as much animals as any other species in the kingdom, but our ability to destroy and conquer far exceeds any known defense of the natural world (save some as yet undiscovered that could and may wipe us all out).

Yes, the world may one day recover from the impact of humans... but that will only happen billions of years after we've all killed ourselves off with our glutteny and short-sightness. And, of course, this "modesty" you try to impart on our species as to our destruction powers doesn't help either.

[sihaya]

And as far as foreign species introduction goes.... I want you all who don't think it's a big deal to think long and hard about it every time you try to rid your tank of aptasia.

[icemark]

It amazes me what people can convince themselves of if it makes them feel better.

actually the fact that others don't get it, that some people feel they say that we should play god and try and undo mistakes in the past to this planet makes me feel sad, mostly because they themselves generally do nothing more than spread the panic further. No it does not make me feel better...Makes me feel sad that people fall into that same panic without knowing the whole picture. Are they short- sighted? I guess so. That does not make me feel better about anything.

Invasive species are species that have an unfair competitive advantage over native species. By definition they always have a negative impact on their new environment, be it habitat destruction, monopolization of food or space, predation on native species, introduction of diseases which natives have no immunity for, etc. Their presence leads to decreased diversity and sometimes local or complete extinction of native species.

OHH can you define native next??? Are Native Americans really native??? How long does a species have to be in an environment to be considered native to that environment??? Some arbitrary number of years I am sure.

Wrong. Natural migration and introduction of invasive species are far from being ecologically equivalent. When animals migrate naturally they radiate out to adjacent habitats and their predators almost invariably follow since they tend to have similar environmental requirements. They are subject to essentially the same limiting factors as in their old habitat. As a result the incoming species don't have much of an un unfair advantage and diversity usually goes up slightly or stays about the same.

and lets remember that everything is supposed to be fair not unfair

No one expects the environment to stay stable or species never to go extinct. What some people do hope for is that we will quit forcing it farther from its natural rate of change and to a state of global homogeneity

Do you really believe what you just wrote there??? So if this same clam, got pushed up onto some log in a storm, pushed across the ocean and started again in the bay, would that have been acceptable??? Oh come on. Because man wasn't involved??? Global Homogeneity??? There is no such thing. That is the whole point! But its thoughts like that, that had lead to to the overpopulation scares of the 70's. Are you old enough to remember those??? Those that said the maximum number of people that the earth could support was 5 billion... and that we would be fighting wars for food and water by this year.

Maybe the next thing you'll be trying to tell me is how we have distroyed and cut down all the forests in america (and before you try- there are more acres of forest in just the United States than anytime in the last 200 years).

If I tear down your house eventually someone will build something else there. That's no different to you than if we waited for time and the elements to take their toll and eventually knock it down right?

I am sure the people in New Orleans can relate to that question more than I can, but frankly if you tear it down or nature does, it is the same. Still torn down. But I don't get your point. If it were good livable land of course someone would eventually build there. Be it another house or a golf course or a shopping mall. In nature it is no different. If some animal or plant dies or is pushed out. Eventually the same or another will take its place. If anything that is Global Homogeneity.

[icemark]

Icemark- you're arguments are rather niave. I'll concede that human beings are as much animals as any other species in the kingdom, but our ability to destroy and conquer far exceeds any known defense of the natural world (save some as yet undiscovered that could and may wipe us all out).

Yes, the world may one day recover from the impact of humans... but that will only happen billions of years after we've all killed ourselves off with our glutteny and short-sightness. And, of course, this "modesty" you try to impart on our species as to our destruction powers doesn't help either.

Shortsighted and just plain mistaken thinking like that is what leads us to this panic in the first place.

The world recover from the impact of humans??? What a joke... even if man wiped the surface of the planet clean, life would return in less than 10,000 years... not billions.

Stop listening to the sheep and go look for yourself. Go look on how life starts and migrates to every niche in the world. From the volcanic vents at the bottom of the ocean to the nematodes in the middle of Antarctica there is life everywhere.

Life on this planet is always migrating, moving, expanding, mutating. Expanding into new environments and evolving until it meets a hospitial area. You give man too much credit.

And if you really felt that it was bad that the animals and plants that have migrated (or invaded) the bay or any other non “natural” environment, how come you are not out there pulling up clams, or burning back Kudzu? How come you are not in a boat protesting? How come you are not out there “restoring the natural balance”???

What a joke.

Natural balance is always in change. Too bad some people just don’t get that.

I recycle, I pick up trash on the beach, I clean up when I am hiking and skiing in the mountains, but I also have read, studied, and seen enough to know how the cycle of the world works, and that we are not stewards of this planet, but rather just tenants.