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Entries in round gobies (6)

Wednesday
Jan042012

Exotic Species Threat 'Celebrated' in Song

Just before Christmas, some invasive species experts wrote their own version of the “Twelve Days of Christmas.”

As reported by the Journal Sentinel, here’s a portion of the song intended to increase awareness about exotic species and the problems that they create:

"On the 12th day of Christmas, a freighter sent to me,

"Twelve quaggas clogging: Quagga mussels, which can tolerate colder water than zebra mussels as well as colonize soft substrates, are now the dominant invasive mussel in 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.

"Eleven gobies gobbling: Round gobies are very effective egg predators. Their advanced lateral line system (a series of fish sensory organs) allows them to find eggs that native egg predators are unable to.

"Ten alewives croaking: Until the introduction of Pacific salmon, alewives died off in such great numbers that tractors were required to remove them from Lake Michigan beaches. Salmon now do a great job controlling alewife numbers, but there are still alewife die-offs due to spawning-related stresses.

"Nine eggs in resting: The spiny waterflea and the fishhook waterflea produce tiny resting eggs that can survive long after the mature waterflea has perished. The resting eggs also can survive extreme environmental conditions, so it is imperative to make sure recreational equipment is cleaned to prevent spreading these invasive crustaceans.

"Eight shrimp 'a swarming: The bloody red shrimp, Hemimysis anomala, is one of the Great Lakes' most recently discovered ballast invaders. The effects on the Great Lakes are largely unknown, but the shrimp may compete for food with young fish and have been found in the diet of some fish in the Great Lakes.

"Seven carp and counting: There are seven species of invasive carp in the United States. There are the four collectively known as Asian carp (black, grass, silver and bighead), the common carp, the crucian carp, and last but not least, the Prussian carp (aka the goldfish). While the current focus is on the silver and bighead carp, all of these carp cause problems one way or another. Hopefully, we won't actually be counting any other carp species soon.

"Six lamprey leaping: This is actually some bad lamprey biology humor. Lampreys are poor jumpers, especially when compared with trout and salmon, so a small low-head obstacle or ledge can prevent lampreys from moving farther upstream while other fish leap over the obstacle. Thus, physical barriers or one-way managers are preventing lampreys from invading more streams in the Great Lakes basin.

Wednesday
Jan042012

Breaking News: Invasive Species Declare Moratorium on Spreading to Allow Feds Time to Plan

Here’s some reassuring news from the federal government, which has done such a great job of protecting our ecosystems from Asian carp, quagga mussels, round gobies, and other exotic species. In case you’re still a bit groggy from all of that holiday celebrating, that previous sentence is sarcasm.

Bowing to pressure from commercial shipping interests, the exotic pet industry, and fish farmers, the federal government has done an abysmal job, and it appears that it will keep on keeping on in that vein.

As part of its Great Lakes and Mississippi River Interbasin Study, the Corps of Engineers is offering 90 proposals for keeping Asian carp and other invasives from migrating into and out of the Great Lakes. Under the present schedule, those options would be narrowed by 2015, with final recommendations made to Congress the following year.

Isn’t that great? In the meantime, carp, mussels, and dozens of other invaders will halt their spread and devastation as a gesture of good faith. That’s more sarcasm, folks.

In an editorial, the Toledo Blade recently said this:

“Government officials did little to stop the northerly migration of voracious Asian carp for decades. Evidence of their DNA turned up in 2009 beyond a series of electrical barriers near Chicago that had been set up to repel a smaller and less-threatening exotic species, round gobies. The barriers have since been modified to turn away carp as well.

“That's the plan, anyway. But if it doesn't work, the carp could devastate Lake Erie. More fish are spawned and caught in Lake Erie than in all of the other Great Lakes combined. Most of the activity is in the lake's western basin, near Toledo.

“The obvious solution, widely advocated by leading Great Lakes scientists, is a complete separation of the lakes and Mississippi River watersheds. But that course would be expensive and politically controversial, requiring one of the largest engineering feats in North American history and costing billions of dollars.

“Litigation over the future of Chicago-area shipping locks pitted Illinois against other Great Lakes states, and went all the way to the U.S. Supreme Court. The Obama Administration supported efforts to keep the locks open.

“Frustrated by the agonizingly slow movement of the anti-carp bureaucracy, U.S. Sen. Debbie Stabenow (D., Mich.) is sponsoring a measure that would require the Corps to pick up the pace. It deserves support.”

You can learn more about the Corps proposals and comment upon them (by Feb. 17) by going here. Probably would be best to avoid sarcasm in your comments. 

Tuesday
Dec272011

Atlantic Salmon Recover in New York's Salmon River

The Atlantic salmon is once again reproducing in New York’s Salmon River. For the third year in a row, researchers have confirmed the presence of young salmon in the river.

According to the Associated Press:

“The goal is to re-establish a heritage species that had a prominent place in the cultural history of the region, where early settlers wrote of spearing hundreds of salmon a night during the spawning run.”

Lake Ontario once supported the world’s largest freshwater population of Atlantic salmon. But the fish vanished in the late 1800s as a result of overfishing and habitat destruction.

Government agencies in the U.S. and Canada have maintained an Atlantic salmon fishery by the annual stocking of millions of hatchery fish, but the fish haven’t been able to reproduce in the wild because of a thiamine deficiency caused by eating alewives, an invasive species. Alewives contain an enzyme that destroys thiamine, also known as Vitamin B1.

Possibly the salmon now are reproducing because of the presence of yet another exotic species, the round goby, as forage. Gobies are high in thiamine, which could counter the ill effect caused by the alewives.

Read the full story here.

Wednesday
Sep282011

Red-Bellied Piranhas: Coming to a Fishery Near Your?

How would you like a school of red-bellied piranhas swimming in your favorite fishery?  

Can’t happen, you say. These South American fish can’t survive in U.S. waters, you say.

Remember John Hammond, creator of the dinosaur park in the movie Jurassic Park? He thought that he was populating it with creatures not capable of reproducing. But Malcolm the mathematician insisted that “nature would find a way,” and he proved correct.

Of course, that’s fiction. Couldn’t happen in real life, right?

How about grass carp?  When they were introduced to control aquatic vegetation --- most of it exotic also ---we were told that they couldn’t reproduce in our rivers. But they have.

I fear that’s what is going to happen with more non-native fish, especially those released by irresponsible pet owners. Given enough opportunities, piranhas, their pacu cousins, and other potentially harmful exotic fish are going to join Asian carp, snakeheads, round gobies, and other invaders in our fisheries.

Let’s look at the facts: Tilapia and armored catfish don’t do well in cold weather either. But they’re established in south Florida and Texas. Also, peacock bass and other “tropicals” thrive in the canals in and around Miami. (By the way, peacock bass were intentionally introduced to eat the many other exotic species, after resource managers determined that they could co-exist well with largemouth bass.)

And what about waters that are kept artificially warm year around by power plants? Could piranhas overwinter and reproduce there?

Eventually, I think, we’re going to discover that they can.

And that’s going to happen because people are going to keep buying piranhas and other exotic species and releasing them into public waters when they tire of them or the fish grow too large. Many of these invaders are illegal to possess in some states, but that little technicality doesn’t prevent purchase over the internet.

That’s likely what happened in Texas, where a girl recently caught a red-bellied piranha in a Houston-area lake. Texas Parks and Wildlife is going to conduct an electrofishing survey in the 23-acre fishery to see if others might be there.

Probably they won’t be. But, given enough opportunities in U.S. waters, eventually they will be --- somewhere.

Thursday
Sep152011

As Carp Move Closer, Great Lakes Already Are Being Destroyed by Invasive Speies

Illustration by Daniel Hertzberg

Asian carp migrating ever closer to Lake Michigan aren’t the only threat to the fisheries of the Great Lakes. Exotic species already established there, including round gobies and zebra and quagga mussels, already are doing catastrophic damage.

Fisheries crashing, birds dying of botulism, toxic blue-green algae flourishing. These are some of the unforeseen consequences from introduction of these invaders by ballast water from oceangoing ships.

Writing at OnEarth, Barry Yeoman says the following:

After a decades-long absence, blue-green algae are again flourishing in Lake Erie -- and it’s never been worse than it is this summer. The algal infestation is just one of many factors that biologists in Ohio, Michigan, and elsewhere say are pointing toward an ecosystem in danger of collapse.

And in The Detroit News, David Spratt offers this:

Today, southern Lake Huron is virtually devoid of king salmon, thanks to food web changes wrought by invasive species like zebra and quagga mussels.

The salmon, simply put, have been starved out. Officials estimate that each port city on southern and central Lake Huron has lost more than $1 million in annual revenue that was generated by salmon fishing.

So, hey, maybe we shouldn’t worry about closing the manmade connection between the Great Lakes and the Mississippi River drainage to keep out Asian carp. The fisheries might be so far gone that another invasive wouldn’t matter so much after all.