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Entries in Great Lakes (139)

Friday
Oct272017

Canadians Say Asian Carp Are In Lake Huron

Canadians are saying that they have conclusive evidence that Asian carp now are in Lake Huron. Considering that lake's central location among, that would mean the invaders have easy access  to Lakes Michigan, Erie, and Superior, although the latter might be too infertile and cold for them to thrive there.

Or, if this report is true, carp already could be in Michigan and moved into Huron from there.

Still, this also could be much ado about nothing in terms of the Asian carp that post the greatest threat to the Great Lakes. Those are bighead and silver.

In Canada, grass carp also are commonly referred to as Asian. While they certainly would not be a welcome addition to the lakes, they don't pose the threat to the sport fishery that the other two do. Grass carp feed on aquatic vegetation, which would diminish beneficial fish habitat. But they don't quickly dominate a water body as the other two do.

Bighead and silver, meanwhile, are filter feeders, gobbling up phytoplankton and zooplankton, the base of the food chain for the young of most sport fish, as well important food for shad and other native filter feeders. Also they are prolific, growing large quickly and crowding out other species with their numbers and mass.

Here's one of the Canadian articles about the discovery:

A delegate to last week’s Coastal Municipal Forum says there is now conclusive evidence that Asian Carp are now in Lake Huron.

Dave Myett, a councillor with Saugeen Shores, says the Ministry of Natural Resources has told them they’re able to test the water and determine what kind of fish has passed through by the presence of their DNA. And they say they have found the presence of Asian Carp DNA.

Myett says at this point they can’t tell how many there were or their size. He points out they’re a very elusive species so anyone that either finds a dead one or catches one should notify the ministry.

Myett also points out that given their size and they’ll ability to procreate once they reach a body of water they eventually out eat and dominate other species.

The forum was hosted by the Lake Huron Centre for Coastal Conservation

“We have been led to believe by the Ministry of Natural Resources and Forestry that there is conclusive evidence that the DNA has been detected of the Asian Carp in Lake Huron,” says Myett. “They can test the water at the source points and they can tell what kind of fish has passed through there by telling if the DNA is present in the water.”

“They seem to be an elusive species,” says Myett. “They’re rarely seen on the shoreline or caught. They’re very hard to catch. If someone finally finds a dead one or catches one in a net or fishing, then I’m sure the Ministry would very much like to hear about it.”

Thursday
Sep212017

BUFFALO, N.Y. — Human antidepressants are building up in the brains of bass, walleye and several other fish common to the Great Lakes region, scientists say.

In a new study, researchers detected high concentrations of these drugs and their metabolized remnants in the brain tissue of 10 fish species found in the Niagara River.

This vital conduit connects two of the Great Lakes, Lake Erie and Lake Ontario, via Niagara Falls. The discovery of antidepressants in aquatic life in the river raises serious environmental concerns, says lead scientist Diana Aga, PhD, the Henry M. Woodburn Professor of Chemistry in the University at Buffalo College of Arts and Sciences.

“These active ingredients from antidepressants, which are coming out from wastewater treatment plants, are accumulating in fish brains,” Aga says. “It is a threat to biodiversity, and we should be very concerned.

“These drugs could affect fish behavior. We didn’t look at behavior in our study, but other research teams have shown that antidepressants can affect the feeding behavior of fish or their survival instincts. Some fish won’t acknowledge the presence of predators as much.”

If changes like these occur in the wild, they have the potential to disrupt the delicate balance between species that helps to keep the ecosystem stable, says study co-author Randolph Singh, PhD, a recent UB graduate from Aga’s lab.

"The levels of antidepressants found do not pose a danger to humans who eat the fish, especially in the U.S., where most people do not eat organs like the brain," Singh says. "However, the risk that the drugs pose to biodiversity is real, and scientists are just beginning to understand what the consequences might be."

"Fish are receiving this cocktail of drugs 24 hours a day, and we are now finding these drugs in their brains." --- Diana Aga

Aga has spent her career developing techniques for detecting contaminants such as pharmaceuticals, antibiotics and endocrine disrupters in the environment.

This is a field of growing concern, especially as the use of such chemicals expands. The percentage of Americans taking antidepressants, for instance, rose 65 percent between 1999-2002 and 2011-14, according to the National Center for Health Statistics.

Wastewater treatment facilities have failed to keep pace with this growth, typically ignoring these drugs, which are then released into the environment, Aga says.

Her new study looked for a variety of pharmaceutical and personal care product chemicals in the organs and muscles of 10 fish species: smallmouth bass, largemouth bass, rudd, rock bass, white bass, white perch, walleye, bowfin, steelhead and yellow perch.

Antidepressants stood out as a major problem: These drugs or their metabolites were found in the brains of every fish species the scientists studied.

The highest concentration of a single compound was found in a rock bass, which had about 400 nanograms of norsertraline — a metabolite of sertraline, the active ingredient in Zoloft — per gram of brain tissue. This was in addition to a cocktail of other compounds found in the same fish, including citalopram, the active ingredient in Celexa, and norfluoxetine, a metabolite of the active ingredient in Prozac and Sarafem.

More than half of the fish brain samples had norsertraline levels of 100 nanograms per gram or higher. In addition, like the rock bass, many of the fish had a medley of antidepressant drugs and metabolites in their brains.

Evidence that antidepressants can change fish behavior generally comes from laboratory studies that expose the animals to higher concentrations of drugs than what is found in the Niagara River. But the findings of the new study are still worrisome: The antidepressants that Aga’s team detected in fish brains had accumulated over time, often reaching concentrations that were several times higher than the levels in the river.

In the brains of smallmouth bass, largemouth bass, rock bass, white bass and walleye, sertraline was found at levels that were estimated to be 20 or more times higher than levels in river water. Levels of norsertraline, the drug’s breakdown product, were even greater, reaching concentrations that were often hundreds of times higher than that found in the river.

Scientists have not done enough research yet to understand what amount of antidepressants poses a risk to animals, or how multiple drugs might interact synergistically to influence behavior, Aga says.

Wastewater treatment is behind the times

The study raises concerns regarding wastewater treatment plants, whose operations have not kept up with the times, says Aga, a member of the UB RENEW (Research and Education in eNergy, Environment and Water) Institute.

In general, wastewater treatment focuses narrowly on killing disease-causing bacteria and on extracting solid matter such as human excrement. Antidepressants, which are found in the urine of people who use the drugs, are largely ignored, along with other chemicals of concern that have become commonplace, Aga says.

“These plants are focused on removing nitrogen, phosphorus, and dissolved organic carbon but there are so many other chemicals that are not prioritized that impact our environment,” she says. “As a result, wildlife is exposed to all of these chemicals. Fish are receiving this cocktail of drugs 24 hours a day, and we are now finding these drugs in their brains.”

The problem is exacerbated, Singh says, by sewage overflows that funnel large quantities of untreated water into rivers and lakes. In August, for example, The Buffalo News reported that since May of 2017, a half billion gallons of combined sewage and storm water had flowed into local waterways, including the Niagara River.

Sunday
May212017

BoatUS Offers Safety Tips for Navigating Higher Waters in Great Lakes

With Great Lakes water levels on the rise and expected to continue to increase into summer, recreational boaters could find that deeper water under the keel may open a whole new range of cruising, fishing or sailing grounds to navigation. That same deep water, however, may present unique safety concerns on the water and at the dock, says Boat Owners Association of The United States (BoatUS), the nation’s largest advocacy, services and safety organization.

According to the US Army Corps of Engineers, Lake Ontario is expected to see the largest increase at 17 inches higher over last year and lowland flooding is already hampering the boat-launch season on the lake. The second largest year-over-year increase goes to Lake Superior at 12 inches higher sometime in August, while Lake Huron and Lake Michigan are both predicted to rise 8 inches. Lake Erie is expected to be up 5 inches over last year.

BoatUS offer the following tips for boaters on the Great Lakes in these flooded conditions:

On the water: The good news is that deeper draft vessels may have more options for mooring, anchoring and slip rental, as well as increased access to the water. However, high water shifts sandbars. Traveling at slower speed can reduce the risk of grounding or running gear damage. Transient boaters can contact local TowBoatUS operators on VHF channel 16 for local information. In you’re headed into unfamiliar waters post an extra lookout, and if you’re traveling far, check ahead as locations to tie up may be inaccessible.

On the dock: Many fixed (non-floating), boat docks with electrical service are submerged, potentially compromising wiring and electrical connections. When waters recede and before power gets turned on, inspect the electrical service and consider installing a ground fault protection device if your dock power system does not already have one. Without it, the risk of Electric Shock Drowning (ESD) increases. A dock electrical maintenance check-up is also a good idea to schedule at the beginning of the each season

Wednesday
May172017

A Carp Is Not Just a Carp; Here's the Difference

Many people, including anglers, don't understand that we have several kinds of carp now swimming in our waters, all of them fish from other countries. And all of them problematic in one way or another.

The fish in the top photo is a common carp. It was introduced more than a century ago, with the help of the federal government. It's now in lakes and rivers all over this country, and has degraded water quality in many of them, mostly because it roots on the bottom and stirs up sediment.  State agencies sometimes use a rotenone treatment to wipe out a lake's fishery, primarily because of overpopulation by common carp. When someone says "carp," this is the fish that most people think of.

Grass carp (that's me with an illegally stocked grass carp) were first introduced during the 1960s, to help control aquatic vegetation, mostly exotic milfoil and hydrilla. The problem is that they eat ALL plants, including beneficial native vegetation. Some have escaped and are reproducing in our rivers. More recently, there's concern that they might establish a breeding population in the Great Lakes. They're far too easy to purchase and stock illegally by people who have no idea of the problems that they cause.

Finally, Asian carp. That description applies to both silver (top) and bighead carp. The silver carp is the one that you see so many photos of as it flies through the air. Both are growing larger here than in their native habitat, with bigheads now exceeding 100 pounds. These are the most recent introductions, brought in by fish farmers in the South. They escaped and now are outcompeting native fish for food and habitat in many of our major rivers, most notably, the Missouri, Mississippi, Illinois, and Ohio. In some places, they account for more than 95 percent of the biomass. There's concern that they, too, will establish breeding populations in the Great Lakes.

Thursday
May112017

Grass Carp Invasion Also Threatens Great Lakes Fisheries

 

While silver and bighead are the Asian carp of most concern these days for the Great Lakes, a third species has quietly been making inroads and is a growing worry for fisheries scientists in both the United States and Canada.

"For the first time, we have a binational, peer-reviewed study by some of the best minds and practitioners in the field who have a consensus on what the risk is to the Great Lakes from grass carp, and it's pretty substantial," said Marc Gaden of the Great Lakes Fishery Commission.

The vegetation eaters, which could decimate wetlands and aquatic grasses, have been found in Lakes Ontario, Erie, and Michigan. And, according to researchers, at least some of these invaders are reproducing.

"They've just been humming in the background," he added. "They haven't gotten a lot of attention. Once in a while one would get captured."

In fact, 23 have been caught in Canada since 2012, including five in Lake Ontario at Toronto, according to Becky Cudmore of Fisheries and Oceans Canada.

"Right now, the sterile fish outnumber the fertile fish. This isn't game over, but we are finding more of these fertile fish."

How did they get into the Great Lakes? Possibly through the manmade connection between the Illinois River and Lake Chicago, before electric barriers were erected. Introduced in the early 1960s to control invasive aquatic plants, they been around far longer than their more notorious cousins.

Likely too, some were introduced either intentionally or by accident. Unlike with silver and bighead, grass carp are easy to acquire and have been introduced illegally into both private and public waters by people who don't understand the consequences.

"Our assessment is saying that yes, they were showing up before, but now they're starting the invasion process," Cudmore said. "They have arrived. Now is the time to act."