Michigan Nature Monday: Dunes

Snow blankets much of Michigan now, which may have you dreaming of summer vacations to the beach, and for good reason – Michigan has plenty to choose from! But sandy shores and their hilly companions—dunes—support more than just a retreat from the daily grind.

Vegetation grows on a dune. Photo by Andrew Bacon.

Dunes in Michigan are unique because, unlike their desert counterparts, they are impacted greatly by the water of the Great Lakes. Fluctuating lake levels contribute to dune formation by stabilizing the dunes with increased water levels as well as increased wave action in high years. These impacts are usually so slow-moving that they go unnoticed, but recent erosion along Lake Michigan due to increased lake levels had the dramatic effect of damaging some houses built close to the edges of these dunes.

One distinguishing characteristic of Michigan’s dunes is the amount of vegetation that can be found on them. There is a limited supply of sand in the Great Lakes being deposited on the dunes. This in time allows for various grasses and trees to take root and grow, further slowing or stopping the movement of the sand and allowing for more vegetation to grow. These plants are therefore critical to preventing erosion and dune migration.

Several rare plant types are supported by these dune habitats including Pitcher’s thistle, Houghton’s goldenrod, and Lake Huron tansy, just to name a few. At MNA’s Lake Huron Sand Dunes Plant Preserve in Chippewa County, a unique natural community known as a “wooded dune and swale complex” exists as a series of sandy ridges and low, swampy areas that were formed in multiple stages as lake levels receded around 12,000 years ago.

Lake Huron tansy. Photo courtesy Peggy & Jerry Keeney.

As with many natural communities throughout Michigan, a major threat to the health of this sanctuary is the impact of invasive species. Particularly at Lake Huron Sand Dunes Plant Preserve, invaders such as Spotted knapweed and European Marsh thistle are aided by habitat disturbance. MNA monitors the sanctuary regularly for signs of disturbance and works to remove invasive species before they become too widespread.

So as you plan your next Michigan beach vacation, remember that the sand is part of a much larger and ever-changing habitat complex.

Native Prairies, Mini-Tsunamis, and Sand Dunes: this week in environmental news

Volunteers collect native seeds that will be used to increase prairies. Image: Heidi Frei

Native prairie restoration fights invasive species and helps the endangered ones (Great Lakes Echo): From flower pots to 100-acre lots, planting native prairie plants is increasingly important as they face threats from invasive species and human development. Prairies in the Great Lakes region are known for hosting bobolinks, wild turkeys, butterflies and a vast array of wildflowers. A program was created to collect seeds from native plants to promote prairie growth and engage volunteers with the environment. It’s something that everyone can help with.

Researchers creating warning system for low oxygen water (Great Lakes Echo): Researchers are developing a system to warn water managers when unpalatable, harmful water from Lake Erie is headed their way. The project, with $1.5 million in federal funding, could give water treatment plant operators time to prepare to treat water that is hypoxic by predicting the movement of oxygen-depleted Lake Erie water. Hypoxia occurs when dissolved oxygen in a body of water is depleted to a level that is harmful to aquatic organisms. This is a particular problem in the central basin of Lake Erie, where it’s deeper.

Large waves on Lake Superior. Image: Greg Kretovic, Flickr

Mini-tsunamis a hazard in the Great Lakes (Great Lakes Echo): The Great Lakes have their own miniature version of tsunamis – more than 100 times per year. That’s according to new research led by the University of Wisconsin Madison. The name of these waves – and the danger that comes with them – are relatively unknown to those in the region. Their name, meteotsunami, is a contraction – broken down, it means meteorological tsunami. They’re about a foot high. And they’re not caused by earthquakes like actual tsunamis. Researchers are now looking into a way to predict when these mini-tsunamis might occur in order to warn beachgoers. According to the study, Lake Michigan is most prone to these mini-tsunamis, followed by Lake Erie and Lake Huron.

Michigan Dune Alliance helps protect Michigan’s iconic sand dunes from invasive species (Model D): From the towering glory of Sleeping Bear Dunes to more modest southern Lake Michigan beaches, perhaps nothing in our state represents “Pure Michigan” better than our iconic sand dunes. But as with so many of Michigan’s fragile native ecosystems, invasive weeds threaten to strangle the dunes. Exotic fungi and invasive bugs are killing the trees that are part of the dune ecosystem, while invasive water plants are choking coastal marshes and interdunal wetlands. There are around 550 miles of coastline on the Mitten’s west that are under siege from alien invaders. Luckily, the combined forces of the Michigan Dune Alliance are on a search-and-destroy mission throughout that long stretch of sand.

Chemicals in the Great Lakes, starving waterfowl and sand dune development: this week in environmental news

By Alyssa Kobylarek, MNA intern

Every Friday, MNA gathers news stories relating to conservation and the environment from around the state and country. Check out some of what happened this week in environmental news:

Common mergansers are just one species of waterfowl that have been found dead due to starvation from the harsh winter. Photo by Andrea Westmoreland via Wikimedia Commons

DNR: Harsh winter leads to starvation, death for waterfowl (mlive): A large number of waterfowl have been found dead across the state due to harsh winter conditions. The die off can be attributed to the large amount of ice coverage on lakes throughout Michigan, preventing the birds from getting food.

Chemicals take various routes to Great Lakes (Environmental Health News): Flame retardants and combustion pollutants from PCBs that Toranto exports to Lake Ontario reach the lake even though they is transported by air. The routes that these chemicals take are important to understand in order to help regulators determine where specific chemicals come from.

Michigan’s DEQ issues permit in controversial dune project near Saugatuck (The Detroit News): Michigan’s Department of Environmental Quality issued a permit to allow the company Singapore Dunes LLC to build a road and 18 housing sites through a sand dune that lies near Kalamazoo River and Lake Michigan. They are avoiding the steep slopes, internal wetlands and endangered species. Those opposed to the project are concerned that this could destroy features of Michigan that make it stand apart from other states.

Extreme precipitation closes beaches, may endanger human health (Great Lakes Echo): Due to runoff from agriculture caused by intense precipitation, officials may close beaches due to E. Coli and other bacteria in the water. Due to high levels of snow and a potentially warmer spring, there could be implications of increased runoff and overflow sewer systems, increasing the transport of bacterium, viruses and other disease-causing microorganisms.

Rattlesnake hunters commonly use the controversial method of gassing rattlesnakes out of their holes. Photo via Wikimedia Commons

Rattlesnake Wranglers, Armed With Gasoline (The New York Times): To encourage rattlesnakes to come out, gasoline is often used to pump fumes into their hole to draw them out. The state of Texas’s wildlife agency is considering banning the use of gas fumes to capture rattlesnakes, adding Texas to the list of more than two dozen states that have outlawed the practice.

Why Michigan is shaped like a mitten: A Glacial Review

by Hannah Ettema

MNA Intern

Everyone does it.

Person A: “What city are you from?”

Person B: [holds up hand and points to location of town.]

Has anyone from Michigan not used their hand to pinpoint their hometown? This is so normal for any Michigander to do. Using hands as maps is a part of Michigan culture.

How exactly are we so lucky to have our state shaped like a mitten? If you were thinking glaciers, you’re absolutely right.

MNA trustee and geologist Mary Ann Czechowski shed some light on Michigan’s glacial history in a recent interview. Mary Ann is a geology consultant and the author of Gold in Michigan.

A glacier is essentially a large river of ice that flows through a landscape.

Johns Hopkins and Gilman Glaciers in Glacier Bay National Park and Preserve

Today, glaciers can be found on every continent except Australia.

There have been four Ice Ages in the Earth’s history.  In the last Ice Age, the Pleistocene Epoch began and lasted from approximately two million years to 12,000 years ago. During this time, warm and cool temperatures alternated and glaciers retreated and advanced in interglacial periods. Around the world, glaciers carved and influenced much of today’s landscape, including the Great Lakes and the state of Michigan.

Like bodies of water, the first glaciers flowed south from what is now Canada seeking the areas of least resistance. It is believed that the Great Lakes were once ancient riverbeds, providing the glaciers perfect pathways south.

With each advance and retreat of the glaciers, the shape and water level of the lakes changed. These changes weren’t happening in a matter of months, but over thousands of years.

Manistique Dune and Swale Nature Sanctuary with prehistoric beaches. Photo: Keith Sayor.

As the shape and water level of the lakes changed, the beaches did as well. When water from the glaciers retreated, it left behind a beach. The Manistique Dune and Swale Nature Sanctuary, recently visited on MNA’s fall adventure, has excellent evidence of these prehistoric beaches. In the sanctuary, a swell of sand will appear out of place among the trees but as you continue to walk towards the current water’s edge, you will walk through various sand swells among trees representing past water levels of Lake Michigan.

Evidence of glacial beaches can also be found at Frink’s Pond and Carl E. McAlvay Memorial Plant Preserves. See the MNA’s sanctuary page for more information on these sanctuaries and others throughout the state.

Many of Michigan’s inland lakes, including Walled Lake and Higgins Lake, were also formed by glaciers. These lakes are called kettle lakes, and were created when chunks of ice would break off the glacier and become embedded in the ground. When the ice chunk would melt, a kettle hole would be left and be filled by water from natural sources.

Goose Creek Crasslands Prairie Nature Sanctuary. Photo: Matt Schultz.

As the glaciers carved the landscape, they left deposits of sediment. Small pieces of rock originally from Canada have been found as far south as in Indiana and Ohio. Here in Michigan the Goose Creek Grasslands Prairie Nature Sanctuary rests in a glacial trough where raw gravel was left by retreating glaciers. Timberland Swamp Sanctuary is a basin that was formed by debris left by the glacier.

Saginaw Wetland Nature Sanctuary. Photo: Meghan Good.

Michigan sits atop bedrock composed of many rock types, including sandstone. As the glaciers eroded the landscape of Michigan, sand became much more prevalent, giving us our sandy beaches, sand dunes and wetlands. The sand blocks the drain of water from land into the lakes, and trapped water creates wetlands, such as the Saginaw Wetland Nature Sanctuary in Huron County.

The sand eroded by the glaciers has also shaped Michigan’s shorelines today. Michigan receives mainly westerly winds, causing the Lake Michigan coastline to have significant dunes not only along the shoreline, but also further inland than usual.

Sleeping Bear Dunes

Lake Huron on the other hand, has fewer dunes due to the fact that the westerly winds blow the sand back into the lake, making for a sandy bottom. Redwyn’s Dunes Nature Sanctuary on the shore of Lake Superior has the only sand dunes on the Keweenaw Peninsula, which were blown in after the glacial retreat

For more information volunteering or visiting sanctuaries, please visit the MNA website . Special thanks to our members for their support and help throughout Michigan.