King Of The Fishes

The Great Lakes-area news is abuzz with the announcement that the US government has appointed an Asian carp czar to oversee efforts to keep Asian carp out of the lakes.

Make It A Fish All

Bad news for fish: viral hemorrhagic septicemia (VHS) was recently found in Lake Superior, meaning that the virus has now been found in all five Great Lakes. (Thanks to TC for the tip)

Carping

With the recent controversy regarding Asian carp in the Great Lakes at the forefront, plus well-publicized problems with zebra mussels and snakehead fish, the Washington Post recently pondered the cost of fighting invasive species.

That Ship Has Already Sailed?

The US Army Corps of Engineers is reporting that DNA evidence suggests Asian carp may already be present in Lake Michigan. In related news, Louisiana is developing a market for carp by rebranding it as "silverfin." Mmmm, silverfin!

Smells Like Teen Lamprey

The Globe and Mail is reporting that biologists have developed a synthetic pheromone that attracts female sea lampreys (Petromyzon marinus) away from males and into traps. The chemical will soon be put to the test in lamprey-infested streams in both Michigan and Canada, and is expected to join lampricides, trapping, and underwater barriers as another tool in the arsenal of those trying to rid the Great Lakes of this invasive species.

For those who want to dig deeper into this research, you can check out the original article in the Proceedings of the National Academy of Sciences (subscription required at the time of this post). Bonus points to the G&M for using the fish's scientific name.

Ballast Bill Set Adrift?

The Muskegon Chronicle is reporting that legislation that would have made ballast water treatment mandatory for ships entering the Great Lakes will not see a vote before the end of the year. That means any efforts to regulate ballast at the national level will have to start fresh in 2009.

Separation Of Perch And Lake?

FOX News, among others, has the story about a new report from the Alliance for the Great Lakes indicating that an "ecological separation" of the Great Lakes from the Mississippi River Basin is the only way to keep some invasive species out of the lakes. They even go so far as to outline several specific scenarios by which this could be achieved, at numerous locations within the Chicago Waterway system. Their plans also include a call for the permanent underwater electric carp fence to be fully activated. To read the report in full, download it here.

Barrier Grief

The Milwaukee Journal Sentinel has an excellent update on the status of the carp-fighting electric fence being constructed in the Chicago Sanitary and Ship Canal. The underwater barrier to carp entering the Great Lakes has been under construction for several years. Now the Army Corps of Engineers is set to turn it on, but at a lower voltage per square inch than would be needed to keep smaller fish from passing through. At issue is the safety of barges passing through the canal, and the risk of hurting anyone who has the misfortune of falling overboard.

Damming With Feint Praise

There was an interesting new study published in last month's Frontiers in Ecology and the Environment regarding the propensity for man-made reservoirs to act as, well, reservoirs for aquatic invasive species. Researchers looked at five well-known invaders in the Great Lakes region: Eurasian watermilfoil (Myriophyllum spicatum), zebra mussels (Dreissena polymorpha), spiny water fleas (Bythotrephes longimanus), rainbow smelt (Osmerus mordax), and rusty crayfish (Orconectes rusticus). They found that the reservoirs and other man-made impoundments not only hold more invaders than natural lakes, they also increase the risk of invasive species being introduced to those natural lakes. The University of Wisconsin has a press release on the topic, or you can download the full research article.

A Seaway Of Controversy

There's an editorial in last Tuesday's Milwaukee Journal Sentinel calling for the closure of the St. Lawrence Seaway in order to prevent ocean-bound ships from transporting new invasive species into the Great Lakes. The reasoning behind the idea is that freighters should be banned from the Seaway until the shipping industry can prove that appropriate measures are being taken to avoid introducing ballast invaders to the region. The Journal Sentinel also published an in-depth two part article on the subject last week.

Got an opinion on this? The MJS is looking for letters to the editor on the subject - details are at the end of the editorial.

(Thanks to Tracy C. for psychically pointing me towards this story ;-))

Smells Fishy To Me!

A press release from the Great Lakes Fishery Commission details new research that may lead to an effective control for the invasive round goby (Apollonia (Neogobius) melanostomus). According to the release, scientists have discovered that scent cues successfully attract female round gobies to traps. What scent, you ask, can pull a round goby away from her other activities deep in the Great Lakes? Male goby urine. The scientists are hoping further studies will reveal a way to set traps using the urine, allowing them to potentially disrupt the breeding cycle of these invasive fish.

Fun With YouTube

Recent YouTube videos with a fresh, crisp, invasive species theme:

• The Statesman Journal has an interesting report about the Oregon Department of Fish and Wildlife's search for non-native fish species in the wild. There's one about invasive American bullfrogs as well.
• Someone was nice enough to capture the lecture given David Orwig of Harvard Forest about the hemlock woolly adelgid and stick the whole thing on YouTube.
• The Florida Department of Agriculture has a creepy, crawly PSA about the Mexican red-rump tarantula.
• The Great Lakes Mayors hosted an hour-long panel on invasive species issues.
• The Zoological Society of London posted a video about surveys for invasive species in the Thames River, including the Asian clam and the zebra mussel.

Post, Nuclear

The Post-Standard is reporting that zebra and quagga mussels (Dreissena polymorpha and D. bugensis) were indirectly responsible for the shut-down of a nuclear power plant on three different occasions last September and October. The James A. FitzPatrick Nuclear Power Plant in New York relies on water intake pipes from Lake Ontario, which is inhabited by both mussel species. While the official cause of the shutdowns was wave action leading to the clogging of the intake pipes with the green alga Cladophora, the mussels are being blamed for the proliferation of algae since 1) they don't eat it 2) their filtering abilities are clearing up the lake, allowing sunlight to reach lower depths and spurring the production of more Cladophora and 3) their waste products act as fertilizer to further enhance algae production. Plant workers have responded by enhancing the screens and other contraptions in place to keep the intake pipes clear.

Update: In related news, the mussels discovered late last year in the Pueblo Reservoir in Colorado have turned out to be zebra mussels - a new species for that state. (If you follow the ISW Twitter feed, you found that out about six hours ago.)

(Tip of the virtual hat to the Protect Your Waters website for linking to the power plant story.)

Botox For The Birds

A story from the AP is suggesting that the recent swarm of bird deaths in Michigan are the indirect result of the proliferation of invasive species in the Great Lakes. The birds are washing ashore at Lake Michigan by the dozen, with the cause of death determined to be avian botulism (type "E"), one of several episodes to occur over the past few years. The botulism itself is not considered invasive, but scientists are speculating that it is getting to the birds through a food chain of invaders: Zebra and quagga mussels (Dreissena polymorpha and D. rostriformis bugensis) containing the bacteria that causes botulism (Clostridium botulinum) are either consumed by birds or consumed by invasive round gobies (Neogobius melanostomus), which are then consumed by birds.

I am not sure if invasive species are specifically to blame here, or if it is just that the invaders are so numerous that they now make up a significant portion of the diet of birds that frequent the Great Lakes. Are zebra and quagga mussels the only ones that can filter botulinum bacteria? Do round gobies harbor more of the bacteria than native fish? The AP article glosses over the surface of the full story, so I did some investigating and found the following hypotheses, summarized from this well-written article from Michigan Sea Grant and this one from Wisconsin Sea Grant:

• Invasive mussels create a type of habitat that is more favorable for the growth of Clostridium botulinum.
• Zebra and/or quagga mussels filter at a much faster rate than native mussel species, allowing the toxins and pathogens that they filter out to build up to a greater degree than similar-sized native species.
• The filtering power of these invasive mussels clears the water, allowing the algae Cladophora to grow. When this algae reaches sufficient numbers and then dies, the resulting anaerobic water conditions encourage the growth of Clostridium botulinum.

It is important to note that none of these hypotheses have yet been proven to be an underlying cause of avian botulism. Research continues in both the US and Canada in order that we might one day understand the cycle of bird deaths and stop it from repeating. Until then, the invasive mussels may seem the most obvious target of blame but it could turn out that the situation is much more complicated.

One Lake At A Time

In an attempt to slow the spread of VHS (Viral Hemorrhagic Septicemia) in their state, the Wisconsin Department of Natural Resources has enacted emergency regulations stating that anyone exiting a body of water must now make sure to drain his/her boat and fishing equipment. VHS, first discovered in the Great Lakes Region in 2005, infects mostly salmonid types of fishes (salmon, trout, etc.) and remains viable in water for up to two weeks, meaning that it could be spread easily by angling activities. Perhaps more frustrating for anglers is the additional rule that any fish taken away from a body of water in Wisconsin must be dead, even bait fish. As a fishing guide says in this story from WJFW, that could be a pain for anyone wanting to visit multiple bodies of water in a single day.

Nightswimming

U-M News is reporting that researchers at the University of Michigan may have found the key to how round gobies (Neogobius melanostomus) managed to spread so quickly through the Great Lakes. Round gobies are typically bottom-dwellers, which would make it difficult for them to get sucked into ballast water, since ships typically take on ballast near the top of the water column. Now a new study has discovered that when the gobies first hatch, the tiny larvae rise to the surface of the water at night, to find food and presumably evade predators, and then descend again in the morning. The new insight into round goby behavior also provides an insight into how ships become a vector for this invasive fish species.

Interested readers can find the abstract to the original research article here, but to see the full version you'll need a subscription to the Journal of Great Lakes Research. Thanks to John R. from Don Watcher for sending in a link to the story.

Fish Tanked

Viral Hemorrhagic septicemia (VHS) continues to take its toll across the Great Lakes Region. Newswise is reporting that numbers of native muskellunge (Esox masquinongy) in the St. Lawrence River have plummeted over the past four years, in part due to VHS. Back in 2003, scientists at the State University of New York (SUNY), who have been monitoring muskellunge populations, caught more than 40 of the fish. This year, they've only caught four, and an investigation into the dozen or so dead fish collected in 2006 indicated several had been killed by the effects of VHS. Unfortunately most of those dead muskellunge were large mature females, which doesn't bode well for the species as a whole.

Click over to the news story to check out a video explaining VHS and showing the SUNY scientists at work. Thanks to budak for sending in a link to this story.

Worm Wishes

Posting on location from Cornell University's Citizen Science Toolkit Conference...

One of the many projects represented at the conference is the Great Lakes Worm Watch. It's a full-featured citizen science project from the University of Minnesota's Natural Resources Research Institute. Volunteers can send in samples, join existing studies, or best of all, design their own earthworm surveys.

Earthworms are not native to the Great Lakes region, but they've certainly made their presence known. Check out the Worm Watch website to find out more about the way non-native earthworms impact forest ecology, and if you're in the Great Lakes Region, consider joining in on the research!

Like A Boat Out Of Water

An environmental group is calling for drastic measures to prevent the further introduction of invasive species into the Great Lakes. According to this article at mlive.com, the Healing Our Waters-Great Lakes Coalition is suggesting that no international ships be allowed to enter the Great Lakes until the U.S. sets federal regulations for how ballast water is dealt with. They've even gone so far as to commission a study showing what the cost would be of diverting the ships and using alternate transportation for goods (more than $50 million, but far less than the estimated $5 billion/year for invasive species management in the Great Lakes region). It has been five years since the U.S. government first considered the idea of ballast water regulations, and some states have become so frustrated with the lack of activity that they're passing their own laws to deal with the issue.

Thanks to John R. from Don Watcher for sending in a link to the story. Interested readers may also want to check out this related press release from the Great Lakes Coalition.

Game Fish Theory

According to this report at The Mining Journal (and many other sources), a recent government study concluded that sport fishing in Lake Michigan has the serious potential to be negatively impacted by invasive species. A team of scientists from the USGS Great Lakes Science Center surveys the lake annually, and in fall 2006 they found that while prey fish were at their lowest levels since the 1970s, populations of invasive species like the round goby and the zebra mussel were at their highest ever recorded. Unfortunately, prey fish are crucial food sources for larger game fish, like salmon and alewife, that fishermen seek. The researchers are concerned that zebra and quagga mussels are consuming nutrients that would typically be taken up by zooplankton and other tiny organisms that prey fish typically eat, causing prey fish populations to dwindle and leading to crashes in game fish populations as well. Add to this the confounding fact that Lake Michigan is stocked with millions of game fish annually just to keep populations "stable" and you've got...a complicated mess.