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Entries in Great Lakes (112)

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.

Thursday
Jan022014

Harmful Algal Blooms Are Growing Problem for Fisheries

 

Click on photo to see map of toxic algae alerts during summer of 2013.

Traditionally a problem in the Midwest and around the Great Lakes, harmful algal blooms (HABs) are a growing problem nationwide, according to the National Wildlife Federation’s Great Lakes Regional Center. For example, Kentucky officials found toxic algae (at four lakes) during 2013, for the first time ever.

“No one wants a green, sick lake,” said Andy Buchsbaum, regional executive director. “And yet that’s what communities across the country are facing. Excessive runoff is feeding an explosion of toxic algae that is choking our waters, closing our beaches, and posing a threat to people, pets, and wildlife. This is a national problem that demands a national solution.”

This past summer 21 states issued advisories and warnings for HABs at 147 locations. While New York led the way with 50 warnings, a bloom covered Florida’s St. Lucie River and Indian River Lagoon with fluorescent green slime, killing fish, dolphins, manatees, and birds.

In an attempt to increase public awareness of this problem, the center teamed with Resource Media to release a report, “Toxic Algae: Coming Soon to a Lake Near You.” Additionally, the communications company also created a first-of-its kind national online map to show locations of blooms.

The problem is flying below the radar, the center said, because no federal agency tracks closures and warnings nationally, few studies have assessed the national cost of HABs, and not enough states monitor their waters.

Friday
Dec202013

Microplastic Beads Pollute Great Lakes

An array of skin care cleansers on the market promise to exfoliate and unclog pores. Some of these skin-scrubbing products contain tiny beads of plastic scattered through a gel or creamy paste. After washing with these cleansers, consumers rinse the soapy stuff—along with its teeny spheres—down the drain, giving nary a thought to what happens to the plastic bits, which are less than 1 mm in diameter.

Now, researchers are finding plastic microbeads in the Great Lakes. They say the miniscule spheres could harm aquatic animals that mistake them for food. Perhaps more ominously, they worry that the plastic balls could help transfer toxic pollutants from the Great Lakes to the food chain, including fish that people eat.

Read more here.

And this from Michigan State University:

Microplastics are a common finding among ocean researchers, and are troublesome because they can act as a sponge for pollutants, such as polychlorinated biphenyls (PCBs). They can also directly harm aquatic organisms, as when fish mistake these particles for food. So are Great Lakes fish eating plastic? The Ohio Department of Natural Resources fisheries researchers have found plastic in yellow perch during their ongoing diet analysis studies.