ScienceDaily (Aug. 6, 2011) — A repellant for sea lampreys could be the key to better controlling one of the most destructive invasive species in the Great Lakes, says a Michigan State University researcher.
Scientists have seen the effect alarm cues have on lampreys. When scents from dead sea lampreys are poured into a tank of live ones, the lampreys' efforts to escape are dramatic. In the past, these reactions were simply dismissed as novel. But Michael Wagner, MSU assistant professor of fisheries and wildlife, sees this reaction as a potential game changer.
"Sea lampreys are one of the most costly and destructive Great Lakes' invaders," said Wagner, who published his results in the current issue of the Canadian Journal of Fisheries and Aquatic Sciences. "The effectiveness of the odor combined with the ease in which it's obtained suggests that it will prove quite useful in controlling sea lampreys in the Great Lakes."
Discovering an effective repellant puts research to control sea lampreys on a new path.
Scientists had proven that the destructive species rely on the odor emitted by past generations of larvae to navigate into streams with suitable spawning grounds. Upon arrival, another odor emitted by mature males lures females onto nests to complete spawning. Based on these observations, existing research has fully focused on using pheromones to attract sea lampreys into traps. Once caged, they are destroyed or sterilized and released back into the wild so they can be tracked but cannot reproduce.
But with many scent and environmental cues in natural waterways, using pheromones to attract sea lampreys doesn't always work. On the other hand, repellants -- even in miniscule amounts -- may prove to be much more effective in diverting and corralling them, Wagner said.
"It's kind of like a stop light, a noxious odor that causes them to run away from its source," he said. "By blocking certain streams with these chemical dams, sea lampreys can be steered away from environmentally sensitive areas and into waterways where pesticides could be used more effectively to eliminate a larger, more concentrated population of sea lampreys."
This approach would allow agencies that control invasive species to save money, use less pesticide and manage other resources more efficiently to have a bigger impact on controlling the invasive species, Wagner added.
"Thanks to this exciting new research on alarm substances, we believe we are on track to bring sea lamprey control to a whole new level," said Robert Lambe, chairperson of the Great Lakes Fishery Commission.
Wagner is continuing his research to isolate the exact chemical compound that causes the alarm. His work is supported by MSU's AgBioResearch and the Great Lakes Fishery Commission
http://www.sciencedaily.com/releases/2011/08/110805163544.htm
Showing posts with label Great Lakes. Show all posts
Showing posts with label Great Lakes. Show all posts
Sunday, August 7, 2011
Monday, November 29, 2010
Lake invaders may be killing birds
Scientists suggest invasive mussels in the Great Lakes may be responsible for the deaths of thousands of migratory birds.
The hunt is on in the upper reaches of Lake Michigan to count what's believed to be thousands of bird carcasses that have washed ashore this fall — a staggering toll blamed on the disruptive powers of invasive species that have taken root in the Great Lakes.
The great debate in the Asian carp crisis, still playing out in federal court and the halls of Congress, is whether the feared fish has the capability of establishing a thriving population in the Great Lakes. If so, bighead and silver carp will almost certainly, and dramatically, alter commercial and recreational fishing in the nation's largest freshwater body.
But what if, as some scientists suggest, the Great Lakes' natural defenses — plankton shortages, lower water temperatures, greater water depth and swift-moving currents — keep Asian carp from sustaining themselves in large numbers? Will the threat have been avoided?
The answer is that all invasive species bring consequences that few can predict, leading scientists to ponder the thousands of gulls, loons, mergansers and other migratory birds whose remains wash ashore along the white-sand beaches in northern Wisconsin and Michigan's upper peninsula each fall.
There is a somewhat controversial theory for this annual die-off, which by some estimates has claimed more than 100,000 birds in the last 15 years, and it involves a type of naturally occurring but deadly botulism linked to the spread of invasive zebra and quagga mussels, which entered the Great Lakes decades ago aboard ocean vessels.
"There's still a lot about this we don't know," said Joe Kaplan, of the Michigan-based nonprofit Common Coast Research & Conservation. "The one thing we do know is that it's killing a lot of birds that are important to us.
"This is a very serious problem that deserves more attention."
Like Asian carp, zebra and quagga mussels reproduce rapidly and overwhelm their environment. Scientists feared densely packed clusters of mussels would take a toll on industry, colonizing in water pipes, intake valves, and air conditioning and cooling systems. And they have.
The U.S. Geological Survey, which has studied zebra and quagga mussels for more than 20 years, rank them among the most destructive "biological invasions into North America." But few could foresee the carnage that has followed.
Zebra mussels and quagga mussels filter naturally occurring botulism and other toxins from the water. Round gobies, another problematic invasive species, eat the mussels, and birds, in turn, eat the gobies.
"The evidence is there to suggest this is happening, but it's circumstantial evidence because we haven't found any proof of it," said Tom Cooley, a biologist at the Michigan Department of Natural Resources. "All we can really do at this point is to continue to monitor what's happening and maybe something in the lakes will turn around."
Michigan's DNR and the Common Coast Research & Conservation are among the organizations, including the USGS and the National Wildlife Health Center, studying the deadly phenomena that this year is expected to kill as many or more birds than died in the oil spill in the Gulf of Mexico last summer.
Scientists don't know how long botulism or similar toxins have been killing birds in the Great Lakes, but the first sizable counting came in 1999, when researchers recorded 311 birds off the shores of Lake Erie. The following year, they found 8,000 around the Great Lakes and the death counts have remained in the thousands every year since.
For now, the deaths appear limited to the northern Great Lakes region, where the concentrations of mussels and birds are higher. But so little is known about the environmental factors that contribute to these deaths that scientists can't rule out large numbers of dead birds washing up along the shore closer to Chicago and western Michigan.
After two "low years" the death toll seems to have risen again this fall, Kaplan said, with perhaps as many as 50 dead birds recovered for every mile of beach. That may be because the unusually hot summer around the Great Lakes produced more algae, which feeds the mussels' population explosions. Or it may be attributed to other factors scientists haven't yet explored.
"We're still learning," Cooley said.
The die-off has devastated the populations of a number of important and protected bird species, but the discovery of many hundreds of common loons, a threatened species in Michigan, has given researchers a rallying point to draw attention and hopefully more funding to this issue, Kaplan said.
But with so much money already being spent to minimize the spread of invasive species within the Great Lakes, and recently to stop another from entering, Kaplan said he realizes this fight may be unwinnable.
"Unfortunately, we don't begin to really study an issue until we see entire systems collapse or get out of control," Kaplan said. "But that comes at a high cost."
By Joel Hood, TRIBUNE REPORTER
http://www.chicagotribune.com/news/local/ct-met-lake-michigan-bird-deaths-20101127,0,918715.story
The hunt is on in the upper reaches of Lake Michigan to count what's believed to be thousands of bird carcasses that have washed ashore this fall — a staggering toll blamed on the disruptive powers of invasive species that have taken root in the Great Lakes.
The great debate in the Asian carp crisis, still playing out in federal court and the halls of Congress, is whether the feared fish has the capability of establishing a thriving population in the Great Lakes. If so, bighead and silver carp will almost certainly, and dramatically, alter commercial and recreational fishing in the nation's largest freshwater body.
But what if, as some scientists suggest, the Great Lakes' natural defenses — plankton shortages, lower water temperatures, greater water depth and swift-moving currents — keep Asian carp from sustaining themselves in large numbers? Will the threat have been avoided?
The answer is that all invasive species bring consequences that few can predict, leading scientists to ponder the thousands of gulls, loons, mergansers and other migratory birds whose remains wash ashore along the white-sand beaches in northern Wisconsin and Michigan's upper peninsula each fall.
There is a somewhat controversial theory for this annual die-off, which by some estimates has claimed more than 100,000 birds in the last 15 years, and it involves a type of naturally occurring but deadly botulism linked to the spread of invasive zebra and quagga mussels, which entered the Great Lakes decades ago aboard ocean vessels.
"There's still a lot about this we don't know," said Joe Kaplan, of the Michigan-based nonprofit Common Coast Research & Conservation. "The one thing we do know is that it's killing a lot of birds that are important to us.
"This is a very serious problem that deserves more attention."
Like Asian carp, zebra and quagga mussels reproduce rapidly and overwhelm their environment. Scientists feared densely packed clusters of mussels would take a toll on industry, colonizing in water pipes, intake valves, and air conditioning and cooling systems. And they have.
The U.S. Geological Survey, which has studied zebra and quagga mussels for more than 20 years, rank them among the most destructive "biological invasions into North America." But few could foresee the carnage that has followed.
Zebra mussels and quagga mussels filter naturally occurring botulism and other toxins from the water. Round gobies, another problematic invasive species, eat the mussels, and birds, in turn, eat the gobies.
"The evidence is there to suggest this is happening, but it's circumstantial evidence because we haven't found any proof of it," said Tom Cooley, a biologist at the Michigan Department of Natural Resources. "All we can really do at this point is to continue to monitor what's happening and maybe something in the lakes will turn around."
Michigan's DNR and the Common Coast Research & Conservation are among the organizations, including the USGS and the National Wildlife Health Center, studying the deadly phenomena that this year is expected to kill as many or more birds than died in the oil spill in the Gulf of Mexico last summer.
Scientists don't know how long botulism or similar toxins have been killing birds in the Great Lakes, but the first sizable counting came in 1999, when researchers recorded 311 birds off the shores of Lake Erie. The following year, they found 8,000 around the Great Lakes and the death counts have remained in the thousands every year since.
For now, the deaths appear limited to the northern Great Lakes region, where the concentrations of mussels and birds are higher. But so little is known about the environmental factors that contribute to these deaths that scientists can't rule out large numbers of dead birds washing up along the shore closer to Chicago and western Michigan.
After two "low years" the death toll seems to have risen again this fall, Kaplan said, with perhaps as many as 50 dead birds recovered for every mile of beach. That may be because the unusually hot summer around the Great Lakes produced more algae, which feeds the mussels' population explosions. Or it may be attributed to other factors scientists haven't yet explored.
"We're still learning," Cooley said.
The die-off has devastated the populations of a number of important and protected bird species, but the discovery of many hundreds of common loons, a threatened species in Michigan, has given researchers a rallying point to draw attention and hopefully more funding to this issue, Kaplan said.
But with so much money already being spent to minimize the spread of invasive species within the Great Lakes, and recently to stop another from entering, Kaplan said he realizes this fight may be unwinnable.
"Unfortunately, we don't begin to really study an issue until we see entire systems collapse or get out of control," Kaplan said. "But that comes at a high cost."
By Joel Hood, TRIBUNE REPORTER
http://www.chicagotribune.com/news/local/ct-met-lake-michigan-bird-deaths-20101127,0,918715.story
Lake invaders may be killing birds
Scientists suggest invasive mussels in the Great Lakes may be responsible for the deaths of thousands of migratory birds.
The hunt is on in the upper reaches of Lake Michigan to count what's believed to be thousands of bird carcasses that have washed ashore this fall — a staggering toll blamed on the disruptive powers of invasive species that have taken root in the Great Lakes.
The great debate in the Asian carp crisis, still playing out in federal court and the halls of Congress, is whether the feared fish has the capability of establishing a thriving population in the Great Lakes. If so, bighead and silver carp will almost certainly, and dramatically, alter commercial and recreational fishing in the nation's largest freshwater body.
But what if, as some scientists suggest, the Great Lakes' natural defenses — plankton shortages, lower water temperatures, greater water depth and swift-moving currents — keep Asian carp from sustaining themselves in large numbers? Will the threat have been avoided?
The answer is that all invasive species bring consequences that few can predict, leading scientists to ponder the thousands of gulls, loons, mergansers and other migratory birds whose remains wash ashore along the white-sand beaches in northern Wisconsin and Michigan's upper peninsula each fall.
There is a somewhat controversial theory for this annual die-off, which by some estimates has claimed more than 100,000 birds in the last 15 years, and it involves a type of naturally occurring but deadly botulism linked to the spread of invasive zebra and quagga mussels, which entered the Great Lakes decades ago aboard ocean vessels.
"There's still a lot about this we don't know," said Joe Kaplan, of the Michigan-based nonprofit Common Coast Research & Conservation. "The one thing we do know is that it's killing a lot of birds that are important to us.
"This is a very serious problem that deserves more attention."
Like Asian carp, zebra and quagga mussels reproduce rapidly and overwhelm their environment. Scientists feared densely packed clusters of mussels would take a toll on industry, colonizing in water pipes, intake valves, and air conditioning and cooling systems. And they have.
The U.S. Geological Survey, which has studied zebra and quagga mussels for more than 20 years, rank them among the most destructive "biological invasions into North America." But few could foresee the carnage that has followed.
Zebra mussels and quagga mussels filter naturally occurring botulism and other toxins from the water. Round gobies, another problematic invasive species, eat the mussels, and birds, in turn, eat the gobies.
"The evidence is there to suggest this is happening, but it's circumstantial evidence because we haven't found any proof of it," said Tom Cooley, a biologist at the Michigan Department of Natural Resources. "All we can really do at this point is to continue to monitor what's happening and maybe something in the lakes will turn around."
Michigan's DNR and the Common Coast Research & Conservation are among the organizations, including the USGS and the National Wildlife Health Center, studying the deadly phenomena that this year is expected to kill as many or more birds than died in the oil spill in the Gulf of Mexico last summer.
Scientists don't know how long botulism or similar toxins have been killing birds in the Great Lakes, but the first sizable counting came in 1999, when researchers recorded 311 birds off the shores of Lake Erie. The following year, they found 8,000 around the Great Lakes and the death counts have remained in the thousands every year since.
For now, the deaths appear limited to the northern Great Lakes region, where the concentrations of mussels and birds are higher. But so little is known about the environmental factors that contribute to these deaths that scientists can't rule out large numbers of dead birds washing up along the shore closer to Chicago and western Michigan.
After two "low years" the death toll seems to have risen again this fall, Kaplan said, with perhaps as many as 50 dead birds recovered for every mile of beach. That may be because the unusually hot summer around the Great Lakes produced more algae, which feeds the mussels' population explosions. Or it may be attributed to other factors scientists haven't yet explored.
"We're still learning," Cooley said.
The die-off has devastated the populations of a number of important and protected bird species, but the discovery of many hundreds of common loons, a threatened species in Michigan, has given researchers a rallying point to draw attention and hopefully more funding to this issue, Kaplan said.
But with so much money already being spent to minimize the spread of invasive species within the Great Lakes, and recently to stop another from entering, Kaplan said he realizes this fight may be unwinnable.
"Unfortunately, we don't begin to really study an issue until we see entire systems collapse or get out of control," Kaplan said. "But that comes at a high cost."
By Joel Hood, TRIBUNE REPORTER
http://www.chicagotribune.com/news/local/ct-met-lake-michigan-bird-deaths-20101127,0,918715.story
The hunt is on in the upper reaches of Lake Michigan to count what's believed to be thousands of bird carcasses that have washed ashore this fall — a staggering toll blamed on the disruptive powers of invasive species that have taken root in the Great Lakes.
The great debate in the Asian carp crisis, still playing out in federal court and the halls of Congress, is whether the feared fish has the capability of establishing a thriving population in the Great Lakes. If so, bighead and silver carp will almost certainly, and dramatically, alter commercial and recreational fishing in the nation's largest freshwater body.
But what if, as some scientists suggest, the Great Lakes' natural defenses — plankton shortages, lower water temperatures, greater water depth and swift-moving currents — keep Asian carp from sustaining themselves in large numbers? Will the threat have been avoided?
The answer is that all invasive species bring consequences that few can predict, leading scientists to ponder the thousands of gulls, loons, mergansers and other migratory birds whose remains wash ashore along the white-sand beaches in northern Wisconsin and Michigan's upper peninsula each fall.
There is a somewhat controversial theory for this annual die-off, which by some estimates has claimed more than 100,000 birds in the last 15 years, and it involves a type of naturally occurring but deadly botulism linked to the spread of invasive zebra and quagga mussels, which entered the Great Lakes decades ago aboard ocean vessels.
"There's still a lot about this we don't know," said Joe Kaplan, of the Michigan-based nonprofit Common Coast Research & Conservation. "The one thing we do know is that it's killing a lot of birds that are important to us.
"This is a very serious problem that deserves more attention."
Like Asian carp, zebra and quagga mussels reproduce rapidly and overwhelm their environment. Scientists feared densely packed clusters of mussels would take a toll on industry, colonizing in water pipes, intake valves, and air conditioning and cooling systems. And they have.
The U.S. Geological Survey, which has studied zebra and quagga mussels for more than 20 years, rank them among the most destructive "biological invasions into North America." But few could foresee the carnage that has followed.
Zebra mussels and quagga mussels filter naturally occurring botulism and other toxins from the water. Round gobies, another problematic invasive species, eat the mussels, and birds, in turn, eat the gobies.
"The evidence is there to suggest this is happening, but it's circumstantial evidence because we haven't found any proof of it," said Tom Cooley, a biologist at the Michigan Department of Natural Resources. "All we can really do at this point is to continue to monitor what's happening and maybe something in the lakes will turn around."
Michigan's DNR and the Common Coast Research & Conservation are among the organizations, including the USGS and the National Wildlife Health Center, studying the deadly phenomena that this year is expected to kill as many or more birds than died in the oil spill in the Gulf of Mexico last summer.
Scientists don't know how long botulism or similar toxins have been killing birds in the Great Lakes, but the first sizable counting came in 1999, when researchers recorded 311 birds off the shores of Lake Erie. The following year, they found 8,000 around the Great Lakes and the death counts have remained in the thousands every year since.
For now, the deaths appear limited to the northern Great Lakes region, where the concentrations of mussels and birds are higher. But so little is known about the environmental factors that contribute to these deaths that scientists can't rule out large numbers of dead birds washing up along the shore closer to Chicago and western Michigan.
After two "low years" the death toll seems to have risen again this fall, Kaplan said, with perhaps as many as 50 dead birds recovered for every mile of beach. That may be because the unusually hot summer around the Great Lakes produced more algae, which feeds the mussels' population explosions. Or it may be attributed to other factors scientists haven't yet explored.
"We're still learning," Cooley said.
The die-off has devastated the populations of a number of important and protected bird species, but the discovery of many hundreds of common loons, a threatened species in Michigan, has given researchers a rallying point to draw attention and hopefully more funding to this issue, Kaplan said.
But with so much money already being spent to minimize the spread of invasive species within the Great Lakes, and recently to stop another from entering, Kaplan said he realizes this fight may be unwinnable.
"Unfortunately, we don't begin to really study an issue until we see entire systems collapse or get out of control," Kaplan said. "But that comes at a high cost."
By Joel Hood, TRIBUNE REPORTER
http://www.chicagotribune.com/news/local/ct-met-lake-michigan-bird-deaths-20101127,0,918715.story
Thursday, June 18, 2009
Not One, But Two Kinds Of Males Found In Invasive Round Goby Fish
ScienceDaily (June 18, 2009) — Scientists have found the existence of two types of males of a fiercely invasive fish spreading through the Great Lakes, which may provide answers as to how they rapidly reproduce.The research, published in the Journal of Great Lakes Research, looks at the aggressive round goby, a bottom-dwelling fish which infested the Great Lakes watersheds around 1990.
Presently, they are working their way inland through rivers and canal systems and can lead to the decline of native species through competition and predation.
Researchers at McMaster University discovered evidence that in addition to round goby males which guard the nest from predators and look after their offspring, there exists what scientists call "sneaker" males – little males that look like females and sneak into the nests of the larger males.
"The existence of these two kinds of males will help scientists understand how round gobies reproduce, how quickly their populations grow, and track how these populations change over the course of invasion," says Julie Marentette, lead author and a Ph.D. student in the department of Psychology, Neuroscience & Behaviour at McMaster University. "This has the potential to have a significant impact on how researchers tackle what has become a very difficult problem in the Great Lakes."
Because males expend lots of energy or eat less while guarding their nests, and attracting females while providing care can be difficult, males in some species have found a sneakier way to mate, Marentette explains. Instead of courting females and protecting the young, some males will parasitize the courtship –and sometimes the parenting duties –of conventional males. They do this by sneaking into the nests of big males or pretending to be females.
"Prior to our findings, only one type of male reproductive behaviour would have been incorporated into projections and modeling analyses of the population dynamics of round goby invasive capacities", says Sigal Balshine, associate professor in the department of Psychology, Neuroscience & Behaviour and academic advisor on the study. "Our results will shed light on how populations of this invasive species are likely to grow and spread through time and space."
The McMaster scientists compared the physical, hormonal and sperm traits of hundreds of males, and found that the nest-guarding, parental males were big, black and had wide heads. The small female-like sneaker males were tiny, mottled brown and had narrow heads. Both types of males produced sperm, but sneakers produced more sperm than the parental males, and had bigger testes. By contrast, parental males have bigger glands used to produce pheromones that attract females.
Funding for the research was provided by the Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Fund for Innovation, the Ministry of Research and Innovation and the Department of Fisheries and Oceans (DFO).
Subscribe to:
Posts (Atom)