To have a basis for talking about blue-green algae we need to put them into a basic biological and ecological context. One of the first things we learn about biology in school is that living things are made up of cells. There are two types of cells – the more ancient and less specialized cells like those in bacteria (the fancy word for them is prokaryotes) and the larger, more specialized cells like those of plants, animals, and fungi (these cell types are called eukaryotes).

Our biology teacher also told us that ecosystems have three types of organisms that interact to manipulate matter and energy. There are producers that can make their own food (usually by photosynthesis), consumers that eat pre-existing food items, and decomposers that digest dead and dying material for food. In lake systems, decomposers include bacteria and fungi while consumers are all animals from the single-celled protozoans to snails to the fish and birds. Producers are submerged or emergent plants and algae.

The term algae (which is plural, the singular is alga) is a non-technical term for a dozen or so different groups of photosynthetic organisms that are not plants. Basically, if it’s a producer and a botanist doesn’t call it a plant, then it’s an alga. These algal groups include prokaryotes and eukaryotes and range from microscopic single-celled organisms to massive, multicellular kelps (that grow over a hundred feet in length) and seaweeds found in the ocean. Algae can contain pigments that will make it nearly any color you can think of – red, brown, green, and blue-green are the most common. A typical Wisconsin lake might have representatives of six or seven of these algal groups throughout the year.

Two of the more common algal groups in the Midwest include green algae that often accumulate in massive amounts during the summer, forming slippery, golden-brown mats in rocks and sediments that receive light; and blue-green algae that can form mats on the bottom or float free in the water column.

The blue-green algae are more precisely referred to as Cyanobacteria and they are often a major component of our lakes. They are the only prokaryote algae, and fossil evidence indicates that the process of photosynthesis first occurred in the blue-green algae about 3 billion years ago. They are the oldest group of producers on the planet and over this time scale they have adapted to nearly every habitat on Earth (fresh and salt water from frozen pack ice to boiling hot springs, soil, on/in plants, on/in rocks, on/in animals). Biologists believe several thousand species of blue-green algae may exist.

While prokaryotes are usually considered unspecialized organisms, some of the blue-green algae can produce specialized cells. One of these cells is a very resistant spore stage called an akinete. It can tolerate very harsh conditions, even those that kill the regular blue-green algal cells. The other important specialized cell is called a heterocyst and it can do a very rare thing – convert atmospheric nitrogen (nitrogen gas) into a form of inorganic nitrogen that algae and other plants can use. Nitrogen gas, while plentiful (80% of atmosphere), is inert and unusable by algae and plants. Nitrogen can be a scarce nutrient in some ecosystems and the ability to convert nitrogen gas into a usable form gives the blue-greens a substantial advantage under those conditions. These important cellular adaptations and the fact that these ancient organisms have an amazingly adaptable physiology allow them to tolerate conditions that kill most other algae and most plants.

Blue-green algae range from single-celled to colonies of cells enclosed in a sticky sheath to filaments of cells that may be branched or unbranched and may have a sheath. The sheath is important for blue-greens because critters that eat algae have a hard time digesting the material, which tends to stick in mouth parts and digestive systems. That means most animals shy away from eating blue-greens. This gives blue-green algae an advantage over other algae which do not produce such a sheath. As more easily digested algae are consumed by a lake’s animals, ever larger populations of blue-green algae are left behind.

If you put all these advantages together – tolerant of extreme and variable conditions, hardy survival stage, nitrogen manipulation, adaptable physiology, and nasty sheath – you get a group of organisms that is hard to control. Under some conditions they can dominate a lake to the point of rendering it barely navigable, smelly and unpleasant to swim in, and potentially toxic. There are a variety of blue-green algal toxins and they can produce potentially serious liver and/or central nervous system problems. The first officially autopsied human death attributed to ingestion of blue-green algae toxin occurred in Dane County last year, where a teenager died after diving and splashing around in an algae-covered golf course pond.

So why aren’t all lakes overrun by out-of-control populations of crazed blue-green algae? Lakes generally have enough nitrogen, but not the high amount of phosphorus that blue-green algae need. This is the one advantage we have over the blue-greens. Lakes that are low in phosphorus generally face less of a problem with blue-green algae. This advantage is lost when phosphorus runs into the lake from outside sources such as leaky septic systems, lawn fertilizers, underlying lake sediments, or other watershed inputs (agriculture, municipal, industrial). Once this advantage is lost it is hard to regain because biological systems are very good at trapping and recycling important nutrients like nitrogen and phosphorus.

A final point to remember, all lakes are destined to accumulate nutrients and sediments with increasing amounts of plant and algal growth over time and eventually most will fill in. The natural time frame for this could be thousands or tens of thousands of years if outside and/or human inputs are minimal. With human inputs accelerating the process it could be hundreds or thousands of years instead (or less). Many of our lakes in Wisconsin have had human inputs long enough to begin showing this acceleration of lake aging, called eutrophication. Lake algal surveys (especially when combined with watershed and water chemistry analysis) provide a snapshot of where a lake is on this continuum by evaluating the type and amount of blue-green algae present in the system.

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The Wisconsin Lakes Partnership welcomes the following people to the Lakes Team:

Kim comes to the Lakes program after assisting the Biology Department at UW-Stevens Point for the past nine years. Kim will assist UWEX and DNR personnel as well as the general public. She will help coordinate the Wisconsin Lakes Convention, Lake Leaders Institute, Lake Tides newsletter, and other Wisconsin Lakes Partnership publications and events.

Contact Kim for help with finding publications or to assist with any lake-related questions at 715/346-2116 or kbecken@uwsp.edu.

Kevin is the new Lake Coordinator located in Rhinelander. Since 2001, he served as a WDNR Fisheries Creel Survey Technician working out of Woodruff. Kevin will be the lead technical contact person for the nine counties in the eastern half of the northern region (Forest, Florence, Iron, Langlade, Lincoln, Oneida, Price, Taylor and Vilas) for nonfisheries lake management issues including lake grant projects and aquatic plant management. Contact Kevin at 715/358-9231 or gauthk@dnr.state.wi.us.

Tim will support DNR regional lake coordinators, lake research scientists, citizen lake monitors, lake consultants and lake organizations to ensure lake management policies and activities maximize lake ecosystem health while meeting local community needs. Besides extensive work with groundwater legislation, Tim worked as a lake research scientist monitoring lake ecosystems, developing new approaches for managing shallow lakes and exploring the impacts of motorboats on Wisconsin lakes. Tim can be contacted at 608/267-7602 or tim.asplund@dnr.state.wi.us.

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How do we form a lake district? What legal procedures does our lake district need to follow? How do we incorporate? What about voting?

For over 30 years, the Guide to Wisconsin’s Lake Management Law has been a fundamental tool for people with lake organizational questions. This year the guide is getting a facelift, along with some major changes we hope will make it even better. For this new (11th edition) of the publication, the guide has been split into two books with new titles and much more information. They will incorporate recent legal changes to the lake district law from Wisconsin Act 275, along with specific requirements, procedures and helpful suggestions.

New technologies and the growth of the internet are changing the way we get our information.  To keep your information fresh we will be offering an online version where you can always get the latest edition of the guide, laws, regulations, forms and contact information.

Look for the 11th edition coming soon!

The Wisconsin DNR needs your comments on the NR 115 proposal! Comments will be accepted until August 26, 2005. You can review the proposal at http://dnr.wi.gov/org/water/wm/dsfm/shore/news.htm. Comments can be emailed to toni.herkert@dnr.state.wi.us or sent to Toni Herkert, Wisconsin DNR - WT/2, PO Box 7921, Madison, WI, 53707-7921. A comment form is included on the website to assist you in organizing your comments.

Wisconsin’s Shoreland Protection Program, found in Chapter NR 115 of Wisconsin Administrative Code, contains statewide minimum standards for shoreland development that are designed to protect water quality, fish and wildlife habitat and scenic beauty along navigable lakes and rivers. The revision effort seeks to protect public rights in navigable waters while allowing property owners the flexibility necessary to make reasonable use of their properties.

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We often get phone calls and emails from Lake Tides readers with a variety of questions about lake districts. Do you have a question about lake districts that you would like to see answered in Lake Tides? Send it to uwexlakes@uwsp.edu so we can include it in a future issue.

Unlike a lake association, a lake district is actually a governmental body, similar to a town or county (but often without paid staff). As such, there are certain rights and responsibilities that come along with being a unit of government.

First and foremost, lake districts MUST follow Chapter 33 of the Wisconsin Statutes, the chapter that sets forth the legal powers and operations of lake districts. A copy of Chapter 33 can be found on the Wisconsin legislature’s website:

http://www.legis.state.wi.us/statutes/Stat0033.pdf

A lake district has statutory responsibilities to the waterbody, local citizens and taxpayers. Some of those responsibilities include things like public notices, open meetings and open records laws. More detailed information can be found online at:

http://www.uwsp.edu/cnr/uwexlakes/districts

What a monster! Hydrilla (Hydrilla verticillata) is considered the most problematic aquatic plant in the United States, although it has not yet been found in Wisconsin. This plant is native to Africa, Australia, and parts of Asia but was introduced to Florida in 1960 via the aquarium trade. California officials have also traced hydrilla infestations to shipments of mail-order waterlilies. By the 1990s, hydrilla was well established in southern and southwestern states where control and management cost millions of dollars each year. During a ten-year period, Florida spent $56 million dollars for hydrilla control, but still the acreage of the plant doubled.

Hydrilla forms dense mats of vegetation that interfere with recreation and destroy fish and wildlife habitat. Besides the impact to recreational fishing, hydrilla greatly slows water flow. Large mats of fragments can collect at culverts and clog water control pumping stations. Because the plant can alter water chemistry and oxygen levels, major infestations limit sport fish weight and size.

Unlike other problem aquatic plants which reproduce mainly by fragmentation, such as Eurasian watermilfoil, hydrilla spreads by seeds, tubers, plant fragments, and turions. Turions are compact "buds" produced along the leafy stems. They break free of the parent plant and drift or settle to the bottom to start new plants. They are 1/4 inch long, dark green, and appear spiny. Tubers are underground and form at the end of roots. They are small, potato-like, and are usually white or yellowish. Hydrilla produces an abundance of tubers and turions in the fall. One square meter of hydrilla can produce 5,000 tubers. Tubers may remain dormant for several years in the sediment. Tubers and turions can withstand ice cover, drying, herbicides, and ingestion and regurgitation by waterfowl. Once hydrilla becomes established, it is readily spread by waterfowl and boating activities.

Hydrilla closely resembles Elodea canadensis, a native plant in Wisconsin. Hydrilla can be distinguished from Elodea by the presence of tubers, leaves in whorls around the stem (generally five leaves per whorl), serrations or small spines along the leaf edges, and the reddish midrib of a fresh leaf.

Will hydrilla spread to Wisconsin waters? Although most infestations are located in southern states, Wisconsin is not exempt from the menace. Russia is currently battling this monster at the 50^o N latitude range, which is equivalent to the US/Canadian border.

Heron Majesty

It was a wonderfully hot July day on Sawmill Lake in Washburn County. I was paddling a sunny yellow kayak around the shore of the small, wild lake. There were only two other craft out there, carrying anglers, but they were out of sight around a slight bend. The little cove on the southeast side was all mine. Well, mine and the hundreds of bluegills staring up at me from their home in the clear water. They were hiding under the cool green shade of the water lily pads, whose brilliant white flowers had called me over to that particular spot.

It was a slight movement of the otherwise still great blue heron on the shoreline which dragged my attention from the bluegills. As I watched, the heron hunted over the edge of the water on its long legs, so slowly that its movements were almost imperceptible to me. Its legs moved, and its head was up on a straight neck. With no hurry, it moved its neck into an "S," lowering its head over the water. Meanwhile, the wind pushed my kayak towards the heron. I hoped I wouldn’t scare it off before I could see it catch a meal. But it was almost there…a couple more seconds of this quiet posing, and…BAM! The heron’s head shot down, and it came up with…nothing. Hrumph. All that anticipation (on my part) and concentration (on the heron’s part). He flew off to a different part of the lake to try again.

Great blue herons are common sight to many of us. We see them feeding on our lakes, near marshes, and flying overhead on giant wings. But what are they up to when they are out of human sight? Where do they go when they leave Wisconsin for the winter?

Great blue herons are the largest North American members of a family which includes herons, egrets and bitterns. While we often see them as individual hunters, they are not solitary birds. Herons nest in large colonies, called a heronry or a rookery. Nesting in numbers helps them ward off attacks from predators such as raccoons, hawks, snakes, bald eagles and opossums. In Wisconsin and most of the U.S., rookeries occur in lofty trees. Real estate in treeless habitats include shrubs and cacti.

In our corner of the world, great blues arrive to their breeding grounds in early spring, males a few days ahead of the females. The males work busily to build or repair a nest that will be two to three feet wide. As no lumber yards are available, twig stealing is common.

Herons’ courting rituals include stretching and snapping necks, clattering bills, ruffling feathers, and slow flying. Both males and females "dress up" for courting time. Their normally yellow bills and greenish brown legs flush red, the skin between their eyes and bills turns a lime green, and they sport fresh plumage on their chests and backs.

Females lay two to five greenish-blue eggs in the twig nests lined with soft material such as pine needles, grass or moss. Incubation of the eggs lasts about a month, and males share in the chore. Once hatched, both parents work to feed the young birds for about two months. Despite the care, almost 70% of great blues die in their first year. Smaller nestlings often starve or are pushed from the nest and never make their first flight. Those who are stronger and live to fly out on their own are inexperienced hunters who fall prey to predators or human-placed dangers such as fences and utility wires.

Those great blues who survive to adulthood grow to be about 6.5 pounds and 4 feet tall with a wingspan of up to 6 feet! Henry David Thoreau once said, "When the heron takes to flight, what a change in size and appearance! ...There go two great undulating wings pinned together, but the body and neck must have been left behind somewhere." Indeed, the large wings of the heron outsize its body as they beat with a languid and unhurried rhythm. While its size in the air is comparable to the sandhill crane, the wingbeats are different. As another easy indicator, the heron flies with its neck folded in an "S" while the crane’s neck is straight. You might hear a distinctive "kraak" when the bird is flying overhead. The heron, although a relatively quiet bird, also emits a call when disturbed or greeting other herons.

Successful hunting of fish, frogs, salamanders, snakes, crayfish, dragonflies, grasshoppers, and even small mammals and birds is aided by keen eyesight, long legs and a 5-1/2 inch dagger-like bill.

Hunting is accomplished by two methods: "standing" and "walking slowly." Prey caught using either of these methods is swallowed immediately; if the prey is too big, the heron will kill it by beating it on the ground and then pick it apart.

The cold winters in Wisconsin force the great blues, like other birds, to migrate southward. Unlike the human version of "snowbirds," birds migrate for a food source. Our great blues, flying at an impressive 20-30 miles per hour, likely set their sights on the lakes and marshes of southern states or Mexico to spend the winter. They make this trip twice yearly, and it can be for many years. The two oldest known great blues lived until 23 and 20 years, respectively.

While the population of great blue herons is stable now, that was not always so. In the late 19th and early 20th centuries, birds with flamboyant plumage were shot for their feathers, which decorated hats. The Migratory Bird Treaty Act of 1918 put a stop to that practice and saved the great blue (and many other species) from extinction. Today, their main threat is human development. For a successful breeding season, nests need to be located away from disturbances. While there are a few established rookeries in more urban areas, they are anomalies. More commonly, disturbances clear out a rookery. There are many documented instances of a housing development or other human disturbance forcing herons to find a new home. If this occurs during nesting season, a generation of herons is lost.

Preserving rookery sites and consideration for a healthy great blue population today will allow some person many years in the future to kayak around a bend in the shoreline of a small, wild lake and watch as a tall, majestic bird walks slowly in pursuit of bluegills.

The photo of a heron rookery was provided by Dr. Hays Cummins, Miami University.  See his Ohio Birds photo gallery at http://jrscience.wcp.muohio.edu/birds/ohio_birds/toc.html

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Partners in Preservation: Saving Through Land Trusts

Volunteer Monitoring Update: The 2005 Great North American Secchi Dip-In

Were you part of the Great North American Secchi Dip-In this year? From June 25 until July 17, volunteers around the world collected and reported water clarity data. The Dip-In began in 1994 in six Midwestern states, including Wisconsin. It has expanded in participation to almost 400 programs and 6,500 volunteers in all fifty states, three Canadian provinces, and six other countries. A true demonstration of the power of volunteer monitoring, Dip-In participants have created over 32,000 records which are used to map regional differences and detect trends in water clarity. Wisconsin’s Self-Help Lake Monitors are encouraged to report their information at the Great North American Secchi Dip-In website at http://dipin.kent.edu/index.htm.

Some of you may be asking, "What in the world is a ‘secchi’ and why would anyone dip one?" Most volunteers use a Secchi disk to measure water clarity. Water clarity is affected by the color of the water and by particles of silt or clay or small plants called algae, and therefore is a measure of some forms of pollution. The disk itself, commonly colored black and white, is named after a Jesuit priest who first used the disk more than 150 years ago. The disk is lowered into the water, and the depth at which the black and white are no longer distinguishable is a measure of the clarity of the water.

Consider taking part in future Great North American Secchi Dip-Ins as an individual, lake organization or community. Calling attention to this event can be an effective way to generate interest and publicity for the quality of our lakes. Various states have had governors, federal and state representatives, and local officials participate in Secchi dipping for water quality.

The Great North American Secchi Dip-In is sponsored by Kent State University.  You can find more information about it at http://dipin.kent.edu/index.htm.

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The Wisconsin Department of Agriculture Trade and Consumer Protection (DATCP), in conjunction with the DNR, is initiating a survey of atrazine (a commonly used corn herbicide) in Wisconsin lakes. In August, investigators will contact self-help citizen monitors in a set of 100 lakes chosen to meet certain geographic and size criteria to enlist their help in collecting water samples for analysis. DATCP will use the results of this survey to select lakes for a more detailed study in 2006, as well as to determine if further monitoring for pesticides in lakes is warranted. Please contact Paula Allen at DATCP (peallen@wisc.edu) or Tim Asplund at DNR (tim.asplund@dnr.state.wi.us) for more information. Stay tuned for more details and results in future issues of Lake Tides, as well as at the Wisconsin Lakes Convention!

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Reflections