Tag: mcgill university

Ten Threats: Predicting New Invaders

  • Some say it's only a matter of time before the Asian Carp enters the Great Lakes. (Photo courtesy of the USFWS)

More than 160 kinds of foreign creatures are in the Great Lakes right now, and every few months, a new one finds its way into the Lakes. Those invasive species are considered the number one problem by the experts we surveyed. The outsiders crowd out native species and disrupt the natural food chain, and it’s likely more will be coming. Zach Peterson reports scientists are putting a lot of time and effort into figuring out which new foreign creatures might next invade the Great Lakes:

Transcript

There are new problems for the Great Lakes on the horizon. The Great Lakes Radio Consortium’s Lester Graham is our guide in a series that explains that new invasive species are one of the Ten
Threats to the Great Lakes:


More than 160 kinds of foreign creatures are in the Great Lakes right now, and every few months, a new one finds its way into the Lakes. Those invasive species are considered the number one problem by the experts we surveyed. The outsiders crowd out native species and disrupt the natural food chain, and it’s likely more will be coming. Zach Peterson reports scientists are putting a lot of time and effort into figuring out which new foreign creatures might next invade the Great Lakes:


(Sound of boat motor)


Jim Barta is a charter boat captain just above Lake Erie on the Detroit River. He says over the last decade, zebra mussels and other foreign species have altered the habitat of the walleye he fishes for.


Water that once had a brownish hue is now clear. That’s because Zebra mussels have eaten the algae and plankton that used to cloud the water, and that means Barta’s boat is no longer invisible to the fish he aims to hook.


“You could catch the fish a little closer to the boat because they weren’t as spooked by the boat. They weren’t as afraid of what was taking place.”


So Barta had to rethink his tactics. He now casts his lines out further, and he’s changed lures to continue catching walleye.


But there are other problems the zebra mussel is causing. Eating all the plankton means it’s stealing food at the bottom of the food chain. And, that affects how many fish survive and how much the surviving fish are able to grow.


Anthony Ricciardi is trying to help Barta, and other people who rely on a stable Great Lakes ecosystem. He’s an “invasion biologist” at McGill University in Montreal.


Ricciardi looks for evidence that can predict the next non-native species that might make it’s way into the Great Lakes. He says species that have spread throughout waterways in Europe and Asia are prime candidates to become Great Lakes invaders.


“If the organism has shown itself to be invasive elsewhere, it has the ability to adapt to new habitats, to rapidly increase in small numbers, to dominate ecosystems, or to change them in certain ways that change the rules of exsistence for everything else, and thus can cause a disruption.”


Ricciardi says most aquatic invasive species are transported to North America in the ballast tanks of ocean freighters. Freighters use ballast water to help balance their loads. Some of the foreign species hitchhike in the ballast water or in the sediment in the bottom of the ballasts.


Ships coming from overseas release those foreign species unintentionally when they pump out ballast water in Great Lakes ports. Ricciardi says one of the potential invaders that might pose the next big threat to the Great Lakes is the “killer shrimp.” Like the Zebra Mussel, it’s a native of the Black Sea.


“And it’s earned the name killer shrimp because it attacks invertebrates, all kinds of invertebrates, including some that are bigger than it is. And it takes bites out of them and kills them, but doesn’t necessarily eat them. So, it’s not immediately satiated. It actually feeds in a buffet style: it’ll sample invertebrates, and so it can leave a lot of carcasses around it.”


Ballasts on cargo ships aren’t the only way foreign species can get into the Lakes. Right now, scientists are watching as a giant Asian Carp makes its way toward Lake Michigan. It’s a voracious eater and it grows to a hundred pounds or more.


This non-native fish was introduced into the Mississippi River, when flooding allowed the carp to escape from fish farms in the South. A manmade canal near Chicago connects the Mississippi River system to the Great Lakes.


If it gets past an electric barrier in the canal, it could invade. Many scientists believe it’s just a matter of time. Another invasive, the sea lamprey, also got into the Great Lakes through a manmade canal.


But, researchers don’t usually know when or where an invader will show up. David Reid is a researcher for the Great Lakes Environmental Research Laboratory in Ann Arbor. He says they can’t predict the effect an invader will have when it arrives in its new ecosystem.


“That’s the problem. We don’t know when the next zebra mussel’s going to come in. We don’t know when the next sea lamprey type of organism is going to come in. Generally, if you look at the invasion history of the Great Lakes, you’re seeing about one new organism being reported probably about once every eight months.”


Knowing what the next invader might be could help biologists, fisheries experts, and fishermen know what to do to limit its spread. Invasional biologists hope that their work will help develop the most effective measures to limit harm to the Great Lakes.


For the GLRC, I’m Zach Peterson.

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Tapping Nature’s Cupboard for Pollution Cleanup

Often our first impulse to clean up a mess is to reach for a chemical cleaner. It’s the same kind of approach in environmental clean-ups. Often the experts first turn to chemicals to clean up badly polluted areas. A new approach to cleaning up pollution has been evolving in recent years. Instead of creating new chemicals to clean up contaminated areas, researchers are trying to use what Mother Nature already provides. The Great Lakes Radio Consortium’s Victoria Fenner has more:

Transcript

Often our first impulse to clean up a problem is to reach for a chemical cleaner. It’s the same kind
of approach in environmental clean-ups. Often the experts first turn to chemicals to clean up
badly polluted areas. A new approach to cleaning up pollution has been evolving in recent years.
Instead of creating new chemicals to clean up contaminated areas, researchers are trying to use
what Mother Nature already provides. The Great Lakes Radio Consortium’s Victoria Fenner has
more:


Nathalie Ross is standing in front of a big water tank divided into three sections. She’s a scientist
at Canada’s National Water Research Institute. She’s working on a different kind of approach
towards environmental cleanup. She explains she’s letting Mother Nature clean up different
aspects of pollution in each section of the tank.


“The first one is what we call natural attenuation, which is based on the natural process to
degrade contaminants, so that’s what we can call our control.”


In the second section, nutrients are added to the water to feed the existing bacteria to see if they
can be stimulated to clean up the water that’s polluted with chlorinated products.


“The third tank, in addition to the nutrients, we add bacteria. And those bacteria were shown to
degrade the chlorinated products, so we are hoping that it would speed up and also complete the
process to the end where we are hoping to see no contaminant at all.”


What Ross is demonstrating is “Green Chemistry.” Also known as Green Technology, the
concept is simple – instead of creating brand new chemicals, it’s becoming increasingly possible
to use the chemicals and processes already available in nature. The thought is that naturally
occurring compounds will be less harmful than the ones that we invent in the lab.


There are two streams of green chemistry – one is using environmentally conscious principles in
the production of new products and processes – water based paints and fuel produced from corn
are a couple of examples. Nathalie Ross is demonstrating the other stream – using naturally
occurring substances and biological agents such as bacteria to clean up the pollution we’ve already
created.


Jim Nicell is doing similar work. He’s an associate professor in the Department of Civil
Engineering at McGill University in Montreal. He’s working with enzymes that will clean up
toxic waste. He’s found a surprisingly ordinary source of the enzymes – a piece of horseradish
root.


“You can take your horseradish, put it in a blender, get the horseradish sauce if you want and
have it for supper. But before you do that, squeeze out the juice which is pretty awful, raw,
smelly stuff, which actually has a high concentration of this enzyme. I literally took that juice
and added some hydrogen peroxide and into a solution that contained some pretty toxic materials
and they just precipitate out. And so with a very small quantity of this enzyme we can actually
have a major impact on reducing the toxicity of that waste.”


The simplicity of Green Chemistry has been gradually attracting the attention of scientists and industry over
the past fifteen years. In terms of scientific developments, it’s still pretty young. But it’s a
concept that makes a lot of sense to Nicell.


“Nature is a whole lot smarter than we are. It’s had a lot more time than we’ve had to optimize
the way things are carried out. Now, we have a whole bunch of industrial catalysts that we have
made in the past but we don’t have nearly the time or, I guess, the capability, the experimental
setup that nature has had to produce the optimal catalysts.”


It might seem like an ideal solution, but critics say we need to be careful. One of the concerns
which has been raised is ecological balance – whenever large quantities of any substance are
released, even natural ones, there is often a risk that we’ll change the environment in ways we
don’t want to.


Brian McCarry is a scientist with the Department of Chemistry at McMaster University in
Hamilton, Ontario. He says, despite that concern, we shouldn’t be overly worried.


“They’re natural organisms, they’re not pathogenic. I don’t think they’re going to disrupt the
balance of nature. They’re not like putting in some really vigorous organism that takes over.
These are also not mutant, genetically engineered organisms so I don’t think anybody should be
terribly worried about having all sorts of strange genetic material floating around that are now
going to get into the ecosystem and run amok.”


There’s one other big concern about Green Chemistry: the cost. Both Nathalie Ross’s water
project and Jim Nicell’s horseradish experiments are still in the early stages. It’s not clear yet
whether it will be cost effective for large-scale industrial applications. But given the benefits of
green chemistry, advocates hope that the value of using the simple answers nature offers will also
be considered, not just the cost.


For the Great Lakes Radio Consortium, I’m Victoria Fenner.

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