Water, Wisconsin and the Mercury Cycle

Mercury is found in air, water and soil. It occurs naturally and exists in elemental or metallic forms and organic or inorganic mercury compounds. Older thermometers contained elemental or metallic mercury that is liquid at room temperature. The liquid transforms into a colorless, odorless gas when heated.

Humans are most likely to be exposed to mercury by eating fish or shellfish that are contaminated. Exposure to mercury can affect the nervous system and harm the brain, heart, kidneys, lungs, or immune system. While mercury used to be used more commonly in science and medicine, now regulations are increasing by organizations such as the U.S. Environmental Protection Agency (EPA).

A series of seven mercury podcasts has been produced by the UW Water Resources Institute (UW-WRI). The episodes cover the history of man's interactions and research dealing with mercury, problematic aspects of the mercury cycle, and the water cycle in Wisconsin. With iTunes already installed, simply click here to launch the podcasts. For reading suggestions on mercury, see the library's new recommended reading list.

Image property of UW-WRI

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 nd.edu.

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.

Ice Cover on Madison Lakes

Lake Mendota's surface area at approximately 9,730 acres is about three times the size of Lake Mendota's at about 3,272 acres, but Mendota's deepest point of 83 feet is not much deeper than Monona's at 74 feet. Another commonality these two lakes share is a pattern involving the seasonal formation and melting of surface ice. Records dating back to 1855 have helped scientists to identify the slow decline in the number of days that the ice cover is present on these two Madison lakes. In those 150 years, the lakes haven't lost just a few days of ice cover, but about a month's worth. This has several ecological repercussions.

Surface ice is responsible for regulating the lake's temperature, dissolving oxygen levels, reducing evaporation, helping to maintain the lake's surface area, and providing a holding place for snow which in turn blocks the sun's rays from the unseen waters, among many other things. Aquatic ecosystems are very complex and even minute changes can leave lasting effects. Ice cover decline is just one of the places climate change can be seen around us.

Read the full story by climateWisconsin.org for more details. For further reading on climate change, view the library's recommended reading lists here. To read more about Madison lakes, see this reading list.

Photo: Three students on frozen Lake Mendota by Amy De Simone

How's that Madison Tap Water?

Keep drinking, there is no cause for concern at present. An article in the Wisconsin State Journal explains the recently detected presence of the contaminant chromium-6 in local drinking water, but at a level that is likely below federal health safety limits. According to the US EPA, this inorganic chemical usually comes from "discharge from steel and pulp mills or erosion of natural deposits." Chromium-6 by itself is not monitored by the EPA, but as part of the chromium whole. They may be implementing new limits for chromium-6 though because a study found that after prolonged exposure to it, some mice and rats developed cancer. Madison wells are still safe though.

For more information, read the aforementioned State Journal article, visit the EPA's Drinking Water Protection site, or browse the library's recommended reading list on Drinking Water Quality.

Photo credit: John Hart, State Journal Archive

Friday Fish Fry? Try the Great Lakes Whitefish

In Wisconsin we know that there aren't too many things better on a Friday than a tasty fish fry. Restaurants all over the state do a booming business serving up fried fish on Friday evenings. Of course there is a bit of history behind the fish fry tradition that you can read about here from UW-Madison folklorist Dr. Janet Gilmore, but what about starting your own family fish fry tradition at home?

Recently published by Michigan Sea Grant, "Wild Caught and Close to Home: Selecting and Preparing Great Lakes Whitefish" offers more than 50 recipes from credentialed chefs and whitefish specialists to help you get started making your own fish at home. For those who are interested in healthier options than frying, it also offers ideas for steaming, poaching, smoking, grilling and pickling, to name a few. It also offers a brief history of whitefish.

The Water Library is acquiring this book,  but if you just can't wait, check out these other books we have to offer on preparing fish. You can check this website for further information on Great Lakes whitefish.

Tsunami Science

Featuring the USGS Tsunami specialist and a clip from NOAA, this quick and informative news video explains the science behind tsunamis. Some important factors include distance from the sea-floor earthquake as well as the topography of the area. The tsunami is caused by an underwater earthquake that forces the ocean floor upward and forcefully pushes the water out of the way, causing it to slam into the shore. The tsunami continues as a series of waves resulting from that undersea earthquake. The waves can be very long lasting and can travel thousands of miles, only stopping from direct impact with a land mass. NOAA and the USGS use monitoring devices to keep track of tsunami activity globally, including near the northern California coast where previous damages have been caused by tsunamis.

For further information about tsunamis, see the NOAA tsunami website. To read about some of the research that is taking place dealing with tsunamis and earthquakes, check this USGS page. The Water Library also has a few tsunami titles for adults and children, please contact us if you are interested in checking these out.