posted 08-22-2012 03:52 PM ET (US)        

http://www.wired.com/wiredscience/2012/08/ the-biology-of-volcanic-pumice-rafts/

posted 08-22-2012 08:22 PM ET (US)            

Just as with land animals, sea creatures habitats are driven by more than weather and currents.

All creatures move with the food supply. If you have ever watched the National Geographic series "Earth" or "Life", the distance traveled for food for some species is amazing. The balance in a given ecosystem is actually fragile and small changes can have disastrous results. If some change does not directly a given creature, it can still remove its food supply from the chain. Most of the non-native invasions that have been publicized laid out a clear, negative impact on the native environment.

I have recommended this book a number of times and I sent Jeff a copy, not sure if he has had the time to read it- "Four Fish" by Paul Greenberg tells a compelling story of the state of the world's fisheries. The scenario is portable. It doesn't just apply to fish, it is plug and play in almost any other environmental or food supply setting. I thought it was an excellent read and provides complementary thoughts to discussion on non-native species, in this cash, farmed fish.

posted 08-22-2012 09:46 PM ET (US)         

In many cases I believe that the human responsibility is to minimize human impact on the earth- if for no other reason than one as selfish as to ensure our own survival in the long term.

A good counterargument to this is where do we draw the line? Why don't I go live in the woods then?

It is all about balance.

posted 08-22-2012 09:56 PM ET (US)            

I think the zebra mussel is a good example. I can't think of any natural way the species could find it's way from Eastern Europe to Mille Lacs in central Minnesota (or anywhere else in North America).

posted 08-22-2012 11:44 PM ET (US)            

This lack of the response on the part of the British government was equally instrumental. This BBC link can summarize it far better than I can. Much of that famine could have been mitigated. http://www.bbc.co.uk/history/british/victorians/famine_01.shtml#five

This was the topic of one of my earliest papers, as an adolescent growing up in heavily Irish populated New England.

From my earlier background in Infectious Diseases, human travel was often the cause of invasion, and is more so, now than ever. Diseases previously confined to a region or continent are the exception now. If you look at the history of HIV, it was spread when a transport road, the N1, was finally built out of Kinshasa, in the Congo, for commercial use. Poor women earned money as prostitutes on the highway and this was the beginning of what is now a global epidemic. HIV entered the U.S., from Africa, via an international flight attendant. HIV is not an exception, it is the common rule for the spread of communicable diseases. Again, it is a plug and play model, whether it is infection or invasion.

posted 08-23-2012 12:06 AM ET (US)         

Evidence left behind from plants and animals can be dated using radiocarbon techniques to determine age, or can be identified in a certain soil/lake bottom layer and dated using cesium-137 or lead-210 decay rates in the surrounding soil. It is pretty fascinating what we can learn by looking at these clues- pollen traces, seeds, clam shells...etc.

posted 08-23-2012 12:07 AM ET (US)         

Evidence left behind from plants and animals can be dated using radiocarbon techniques to determine age, or can be identified in a certain soil/lake bottom layer and dated using cesium-137 or lead-210 decay rates in the surrounding soil. It is pretty fascinating what we can learn by looking at these clues- pollen traces, seeds, clam shells...etc.

posted 08-23-2012 12:27 AM ET (US)            

Maybe nobody has looked.

My larger point is that every living thing today has evolved to survive, and given a chance, will do so. To think that we can somehow alter this is folly in my opinion.

posted 08-23-2012 02:50 AM ET (US)            

Anyhow, the whole native vs. non-native thing is made even more interesting when it is applied to great man-made public works. I had to LOL when I was reading the public commentary about banning two-strokes from Lake Mead. There was a section of letters sent in from folks who were concerned that two-strokes were harmful to the native water and shore line plants. The National Park Service responded by beaning them right between the eyes with a big fat brick of, "duh". The NPS, who both proposed and supported the ban, was forced by simple intellectual honesty to point out that there are no native aquatic flora in Lake Meade, it being a man made lake, in the desert and all, and that they already go to great lengths and expense to eradicate non-native vegetation associated with the lake. Of course, they went ahead with the ban on two-strokes, addressing the section on impact to flora by saying something like, "well, if there were native aquatic plants in/around Lake Mead, we're sure they would be harmed by two-strokes, so we're proceeding with the ban anyway". Must be nice to be king. Billionaire elitist Steve Wynn, who would just as soon keep boating the purvey of the wealthy elite, was very pleased by this.

posted 08-23-2012 08:21 AM ET (US)            

Lake Huron is supposed to be 577-feet above seal level. If the water level in Lake Huron goes down one more foot there would be an enormous outcry and alarm. But a change in level to 576-feet from 577-feet would be a change of only 0.17-percent. Let's compare to something that man has control of; how about a man's body weight? I weigh 220-lbs. If my body weight changed in the same percentage I would gain or lose six ounces. What person maintains their body weight within six ounces over several decades?

posted 08-23-2012 08:38 AM ET (US)            

"The development of thick ice sheets during the Pleistocene epoch warped the underlying crust downward into the mantle, an isostatic adjustment in response to the great weight of the ice. After the ice melted, the weight was removed from the crust and it began to slowly rise back to its preglacial position. This isostatic process, called crustal rebound, is still in progress in the Great Lakes area of the United States."

posted 08-23-2012 09:28 AM ET (US)         

Species' former ranges are studied in the same way- their fossil absence in some areas and presence in others shows that. This is an interesting field of research http://en.wikipedia.org/wiki/Paleoecology

Peter- re: conservation of non-native plants

posted 08-23-2012 10:37 AM ET (US)         

Many of us seem to believe beyond the shadow of a doubt that the planet exists solely to suit our needs and to please us. We call things like milfoil invasive because it wasn't here in our extremely short perspective and it interferes with out enjoyment of a resource. Meanwhile other species are purposely introduced and because we benefit from them they escape the title of invasive. Like mentioned above, we dam major rivers and flood hundreds of thousands of acres with little outcry but freak out when a plant that wouldn't be there if there was no water shows up.

Now don't get me wrong. I am certainly not saying that we shouldn't check our shoes for dog crap before coming inside. Just saying that it may be a bit dramatic to refer to changes due to new species as the destruction of the environment. The evolution of the environment maybe but not the destruction.

One would have to have the blinders on real tight to not step back and look at the big picture and not realize that we ourselves are a pretty significant invasive.

I'm a glass half full kind of guy. I see a milfoil covered cove and instead of being bummed out that I can't water ski there I grab a rod and a largemouth or northern pike lure and see what's there.

This planet is just fine and sometime down the road it will likely be rid of us and evolve into the next phase of its existence. The planet as we know it has only existed for a fraction of its big picture.

posted 08-23-2012 11:01 AM ET (US)            

Anyhow, the whole native vs. non-native thing is made even more interesting when it is applied to great man-made public works. I had to LOL when I was reading the public commentary about banning two-strokes from Lake Mead. There was a section of letters sent in from folks who were concerned that two-strokes were harmful to the native water and shore line plants. The National Park Service responded by beaning them right between the eyes with a big fat brick of, "duh". The NPS, who both proposed and supported the ban, was forced by simple intellectual honesty to point out that there are no native aquatic flora in Lake Meade, it being a man made lake, in the desert and all, and that they already go to great lengths and expense to eradicate non-native vegetation associated with the lake. Of course, they went ahead with the ban on two-strokes, addressing the section on impact to flora by saying something like, "well, if there were native aquatic plants in/around Lake Mead, we're sure they would be harmed by two-strokes, so we're proceeding with the ban anyway". Must be nice to be king. Billionaire elitist Steve Wynn, who would just as soon keep boating the purvey of the wealthy elite, was very pleased by this.

posted 08-23-2012 12:38 PM ET (US)            

Back in the early 80's, according to one of my colleagues who is a native of that area, the Great Salt Lake was rising and threatening the city. They had elaborate plans drawn up to pump it out. That was a time when "smogginess" and air pollution were at their worst. (CA had just implemented modern emission controls and testing, and the rest of the country pretty much had not. It would be at least a decade before the air would be noticeably cleaner like it is now.) Yet for the last decade, after three decades of automotive emission standards, 1/1000th of what they used to be, the lake level has been dropping precipitously. Antelope Island is not even an island anymore. The trivial conclusion, (which I am not supporting), would be that smog keeps lake levels higher. Reality is probably too complex to understand.

As I have said in other threads, I (personally), like the extra clean, clear water in the parts of Lake Mead where the invasive mussels have filtered it clean. I also realize that perspective is selfish, because it is contrary to other users of the lake, like fishermen, where the unnaturally clear water disrupts the natural food chain. Then again, what is the "natural" food chain in an un-natural, manufactured habitat? Here's another one I'd never hear addressed or read in the public commentary: Could the filtering habits of the invaders explain why no two-stroke pollution was discovered in Lake Mead in the period leading up to the ban?

posted 08-23-2012 01:06 PM ET (US)            

Dinosaurs - 165 million years
Humans - 200 thousand years

We are basically newborns on this earth and I agree we only live due to our climate and a brain which allows us to be creative in result allows us to be dominate species to thrive at least right now. As it changes slowly and it seems like it is as far as we know we will witness many types of other species start to dominate thrive as well die. This is normal and it may be very sad at the same time depending on how one feels emotionally on the topic.

As a fisherman who targets salmon I have witnessed first hand since a boy 25 years ago an ocean filled with the species now basically fighting to survive. Yes still salmon to fish for but it has changed from dropping a line and waiting 5 mins to half hour only minutes from shore and catching a limit, to now fishing 5 days straight to get one hit and hopefully get that fish which is hopefully legal size all before a starving seal gets it first.

Not all regions are like this but the early signs are there.