Invasives at Fault for Great Lakes Salmon Dearth?

Four decades ago, salmon were added to the Great Lakes by Michigan fisheries biologists. In the following years, the fishing industry flourished as did the salmon. Cars hauling boats would be lined up with anglers just waiting to get out in the lakes and catch fish. But now, things have changed.

The invasive mussels came in and altered the food web. Alewives, one of salmons’ favorite fish to feed on, have mostly disappeared from the Great Lakes. Without enough time, the salmon were unable to adapt their diet as their food supply disappeared. Walleye, a native species, have returned to the lakes and are also responsible for eating the salmon. Last fall the Lake Michigan salmon never showed up at spawning time. Things aren’t looking good for the salmon.

Listen to the NPR Story for more details.

Photo credit: Coho salmon –


Milwaukee: Waterways without Asian Carp

In November of 2010, researchers from the University of Notre Dame collected water samples from several Milwaukee waterways including the Milwaukee, Menomonee, and Kinnickinnic rivers among others. These water samples were then analyzed to see if they contained Asian carp DNA. The good news is that they do not.

While DNA was found in southern parts of Lake Michigan earlier last year near the Illinois-Indiana border, it seems that the measures taken to block the carp from progressing northward have been successful, at least in keeping the invaders out of Milwaukee’s waters. According to a brief article in the Milwaukee Journal Sentinel, “only one actual fish has been found above the barrier.” Current focuses are on making sure that the carp are blocked from making it further north up the Mississippi River.

More information about this research can be found in this DNR news release. View our previous blog posts on Asian carp here. There are also several books dealing with Asian carp in our invasive species recommended reading list.

Photo credit: Michael D-L Jordan for

Friday with the Phragmites

Maybe something like a dust mite comes to mind, but instead read it as a three syllable word, pronounce the second half “mighty’s” and think plants. Phragmite is the scientific or botanical name for the common reed, often found in wetland areas in temperate and tropical regions of the world. They are perennial plants, meaning that they live longer than two years, and can grow to be 15 feet tall and spread up to 60 feet.

You may have heard more about these reeds lately because they are quite prolific. Sometimes referred to as an invasive species, phragmites in large numbers can be harmful to wetlands. Recently, residents of Grand Haven, MI were invited to a forum to learn more about phragmites and the potential implications for local bayous and rivers. They pose threats  to native species, wildlife habitat and shore views. Because they grow rather densely and spread far, they drink up a good deal of water and make it hard for other plants or animals to get through or share their habitat area. There is scientific debate as to whether this plant is native to North America or had European origins. Since roots grow very deep, one of the best known ways to control this plant is by burning it over two to three seasons.

Read more about phragmites from this USDA site or on this UW Sea Grant page. For general reading on invasive species, see the library’s recommended reading list. We are also working on adding some new kids’ books on invasive species to the collection, so check back soon for those.

Photo from wikipedia.

“The Next Step in your Carpucation”

With the coming of spring also comes National Invasive Species Awareness Week, the first week of March. Staff at the Aquatic Sciences Center have taken this opportunity to educate people a bit about the ever-unpopular Asian carp. An introduction to Asian carp can be read in this previous blog entry. For those who are more familiar with the species, this UW Sea Grant release helps to explain information as relayed by invasive species outreach specialist Phil Moy.

Entitled “Taking Five With an Asian Carp,” this article offers information relating to five surprising facts about the species. Are Asian carp really bottom feeders? Do they relate to algal blooms in any way? What about those zebra mussels and quagga, is there a connection between them and Asian carp? How many types of Asian carp are really out there? These are all questions answered in the press release. For further reading on invasive species, see the library’s recommended reading list.

Photo credit: Chris Young

Against Aquatic Nuisance Species: GLMRIS

Conducted by the United States Army Corps of Engineers (USACE), other federal agencies, Native American tribes, state agencies, local governments and non-governmental organizations, the Great Lakes and Mississippi River Interbasin Study (GLMRIS) will evaluate different methods of preventing the spread of aquatic nuisance species (ANS) between the Great Lakes and Mississippi River through open waterways. Aquatic nuisance species are defined as “a nonindigenous species that threatens the diversity or abundance of native species or the ecological stability of infested waters, or commercial, agricultural, aquacultural or recreational activities dependent on such waters” (GLMRIS page).
The results of this regional study will be available in four years. Concerns have been raised that something needs to be done about Asian Carp now, and critics are wondering if this is the best course of action. State DNRs have positively responded to this project. The study is hoped to provide suggestions for permanent solutions in addition to actions that are currently taking place. For more information, read the Green Bay release.
Study area map from GLMRIS website.

New Rules for Ballast Water in Great Lakes?

On January 26th, a public hearing in Superior will determine if Wisconsin regulations regarding ballast water discharged by ships in the Great Lakes will be changed to match those required by the International Maritime Organization. This would apply to large commercial shipping vessels that travel between the Great Lakes and the ocean. As cargo loads change, the ships take on or expel water in order to stay balanced. This water can also include plants, animals and pathogens. WDNR states “Ballast water is the primary way aquatic invasive species such as the zebra mussel, round goby and spiny water flea have been introduced into the Great Lakes over the last century.” This proposed changed is aimed to combat the threat of invasive species.

For news and information about the Ballast Water Discharge General Permit, view the WDNR’s page. For more information about the proposed changed to ballast regulations, read the WDNR news release. For general reading on Great Lakes ships and shipping visit the Water Library’s recommended reading list.

Photo credit: Frank Koshere, WDNR website

New Funds Allocated to Halt Asian Carp

Many efforts are still being made to stop, or reduce the number of, Asian carp spreading to the Great Lakes. Yesterday $47 million in funds were announced that will go toward 13 different projects of prevention.
In addition to creating a lab in Wisconsin where Asian carp DNA will be sampled, pathways into the Great Lakes are going to be examined with hopes of finding ways to block the route of the fish.
Some of this funding is coming from money that was previously designated by the federal government for clean-up and restoration of the Great Lakes. Arguments have been made that the funding to fight Asian Carp should come from a separate source. For further information, see the Detroit Free Press article.
Photo credit: Brian Kaufman/Detroit Free Press