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Entries in Great Lakes (109)

Wednesday
Feb052014

Asian Carp DNA Found in Lake Michigan

Lake Michigan now has joined Lake Erie as a fishery where Asian carp DNA has been discovered.

A single positive sample for silver carp was found in Sturgeon Bay this past summer, according to the Wisconsin Department of Natural Resources (DNR), which conducted the research along with the University of Notre Dame and The Nature Conservancy.

The water sample wasn’t screened for the presence of carp DNA until recently. It was collected originally in a search for evidence of Eurasian ruffe, another exotic fish species.

Is the finding cause for concern? That’s debatable. But it is reason enough to begin regular sampling of Sturgeon Bay.

“When we start talking about evidence for Asian carp in a system and the use of DNA, we talk about repeated sampling events and repeated detections,” said Chris Jerde, a Notre Dame scientist.

This latest discovery was from just one of 50 water samples taken in Sturgeon Bay and 282 total from the state’s portion of Lake Michigan.

But Jerde added that if Asian carp DNA were commonly spread by bird feces, boat hulls, and other means besides live fish, other positive samples would be noted from across the Great Lakes.

"We can talk about alternative pathways (for DNA to get into a water body), but we still have thousands of negative detections throughout the Great Lakes and we have one positive here."

DNR’s Bob Wakeman added, “It is what it is. We just need to clarify what it means.”

Despite the discovery of positive DNA in Lake Erie and even a couple of live carp over the years, no evidence has been found of a breeding population.

Monday
Jan272014

Indiana Moves to Reduce Pollution of Lake Michigan

Guide Dale Stroschein fights a Lake Michigan smallmouth. Photo by Robert Montgomery

Anglers, environmentalists and many others are pleased with a recent decision by the Indiana Department of Environmental Management (IDEM) to reduce pollution of Lake Michigan and its fisheries.

A stricter IDEM permit requires BP’s Whiting oil refinery, just outside Chicago, to lower its mercury discharges from 23 parts per trillion to 8.75.

“We are pleased the agency responded to our recommendation by strengthening the mercury requirements and requiring BP to submit and update its stormwater plan,” said Lyman Welch of the Alliance for the Great Lakes. “Still, we are disappointed that IDEM did not go as far as we’d hoped to protect the waters of the Great Lakes.”

At BP, meanwhile, spokesman Scott Dean said that new technologies for pollution reduction are promising.

“BP is committed to protecting Lake Michigan and we are cautiously optimistic that our recent investment in new water treatment equipment will further reduce the Whiting Refinery mercury discharge,” Dean said. “Having said that, the mercury limit in the revised permit has decreased by more than half and the refinery needs to gain experience operating the new equipment before we will know if the refinery can successfully and consistently meet this revised limit.”

The company has almost completed a $3.8 billion expansion that will make it a top processor of heavy crude oil from Canada’s tar sand deposits. Following announcement of construction in 2007, IDEM allowed BP to increase its discharge of mercury, ammonia, and suspended solids.

Public outrage over that decision convinced BP to abide by stricter standards for ammonia and dissolved solids. But Indiana allowed an exemption for mercury as the company worked on technology to scrub its waste of that pollutant.

(This article appeared originally in B.A.S.S. Times.)

Monday
Jan132014

Lake Trout Recovering from Lamprey, Alewife Invasions

Lake trout photo by Robert Montgomery

Good news from Lake Huron, where lake trout seem to be reproducing --- finally.

First, sea lamprey migrated into the Great Lakes from the Atlantic Ocean and nearly obliterated them. Resource managers have managed to minimize the impacts of this blood-sucking invader, with millions of dollars spent on mitigation.

Then the alewife, another exotic species, complicated recovery.  As they fed on the prolific baitfish, lake trout sustained a vitamin deficiency that damaged reproduction. Supplemental stocking by the federal government did little to sustain the population.

But about a decade ago, the alewife population collapsed, probably because an overabundance of predatory salmon, yet another introduced species.

So, with lamprey minimized and lake trout now getting the nutrients they need from native forage, they finally are successfully reproducing and could be on the road to recovery, according to Michigan Radio.

 “I felt we were so completely stymied by one thing after another after another. The litany of challenges working against the reestablishment of a self-sustaining lake trout population seemed insurmountable,” said Jim Johnson of the Michigan Department of Natural Resources.  “But then, with the collapse of alewives, everything changed.”  

Read more here.

Friday
Jan102014

Mussel Threat Grows in West

Unlike zebras, quagga mussels can colonize soft substrates as well as hard surfaces, such as this boat prop.

Out West, resource managers are waging a fierce battle to keep zebra and quagga mussels out of their lakes and reservoirs.  I wish them well, but all it takes is one boat out of thousands launched to infect a waterway.

At Lake Tahoe last year, boat inspectors found 36 vessels infested with exotic species, as they inspected more than 7,000 and decontaminated more than 4,000. Most importantly, though, managers found no evidence of mussels in the lake.

Other fisheries were not as lucky, as a quagga infestation was discovered in California’s Lake Piru, with boat quarantines implemented at Cachuma and Casitas.

By the way, quaggas are even more troublesome than zebras, as they can withstand colder water than their cousins and they can colonize soft substrates.

According to the Great Lakes Echo:

“These abilities have helped it colonize most of benthic Lake Michigan. Just like zebra mussels, quagga mussels are quite effective at clogging water intake pipes and other infrastructure. Mitigating these impacts has cost Great Lakes residents millions of dollars.”

The Echo annually publishes Tim Campbell’s invasive-species rewrite of “The Twelve Days of Christmas, which he created in 2011 for the Wisconsin Sea Grant.

“Twelve quaggas clogging, ‘leven gobies gobbling, ten alewives croaking, nine eggs in resting, eight shrimp ‘a swarming, seven carp and counting, six lamprey leapingFIVE BOAT-WASH STATIONS! Four perch on ice, three clean boat steps, two red swamp crayfish and a carp barrier in the city!”

Monday
Jan062014

Great Lakes 'Awash in Plastic'

NOAA photo

At least three of the five Great Lakes “are awash in plastic,” according to Scientific American.

Make that micro plastic, which mostly consists of tiny beads often used as abrasives in personal care products.

 The big questions now are what effects these tiny pieces of pollution are having. The plastic itself could be harmful when ingested, but it also adsorbs chemicals, some of them toxic. That means the health of both fish and the humans that eat them could be at risk.

  “We don’t know what’s going on yet with the fish or the organisms eating the plastic with these pollutants in the Great Lakes,” said Lorena Rios, a chemist with the University of Wisconsin-Superior. “I plan to study whether the endocrine system of the fish is damaged and whether the problem stops there or moves up the food chain in harmful amounts all the way to humans.”

 During 2012, Rios and other researchers found 1,500 to 1.7 million plastic particles per square mile in Lakes Superior, Erie, and Huron. About 85 percent of that was micro plastics, with pieces averaging less than one millimeter in diameter. With more people and industry around it, Erie, not surprisingly, had the highest density.

 Rios didn’t find any plastic in the fish samples that she tested, which were all from Superior. But the Ohio Department of Natural Resources has found plastic in Lake Erie yellow perch during ongoing diet-analysis studies, and is sending samples to the chemist for analysis.

Researchers decided to look at the Great Lakes because micro plastics also are commonly found suspended in ocean waters. That marine pollution already has prompted some companies to announce they will phase out micro beads from their products.