Water Colors: On the 2020 posts of Marquette photographer Shannon Kivi – aka 906 Images – we found magnificent waves that often revealed a glacial blue-green tone, like this one. After we linked to Shannon’s work on our own Facebook page, a fan ask how that color comes to be. We tapped Dr. John A. Downing (in photo), director of Minnesota Sea Grant and a professor of biology at the University of Minnesota Duluth and in UMD’s Large Lakes Observatory. He sent back an informative color guide to our waters that we're sharing here.
Why is water blue or green or brown or pink or red? Every child knows that water is blue and so is the sky. Trees and grass are green. The main reason that a water surface often looks blue when viewed from far away is that it is reflecting the blue of the sky. When one looks at water up closely, though, it can take on a variety of colors. Looking down into a lake or stream, the water may appear colorless if shallow, or blue if pure, or various shades of green, brown or even pink.
Things that change the color we see. There are two kinds of color that we might sense when we look at water: true color and apparent color. Apparent color is how it appears to our eyes when light passes through it and is reflected from particles in it or under it. True color is the color that water would appear if we took all of the particles out of it and passed sunlight (containing many colors) through it. The light we see after sunlight passes through water is the “white” light minus the colors that have been filtered out by dissolved substances in the water or by the water itself.
Blue water. The reason very clear water tends to look blue when we look down into it or through a wave (like in the Caribbean and clear places in Lake Superior) is that water itself filters out most other colors but blue and blue passes through to your eyes. This is due to the structure of water molecules. If waves look very blue to your eyes it is probably because this blue light is reflected back to your eyes by white sand.
Green water. Sometimes, if water is pretty clear but has a little yellow or brown organic material (think extremely weak tea) in it or has yellowish or golden sand under it, it will appear to be green. This is because the blue light passing through pure water mixes with the yellow of organic materials or the yellow reflected by sand, and your eyes see green. Sometimes, however, water is apparently green to your eyes because green particles like algae bounce back that color to your eyes. You can tell the difference between a truly green wave and an apparently green wave by looking to see whether the water seems translucent (light passes through it) or cloudy (light blocked by particles). If it appears translucent to your vision it is probably pure water with a little dissolved organic matter in it or golden sand under it.
Brown water. Sometimes water appears to be brown. Depending on whether it seem translucent or cloudy, brown water can be due to dissolved material from leaves, peat or wetland plants (translucent) or suspended soil or other particles (cloudy). If you have been around bogs or small lakes in the Boundary Waters, you have probably seen translucent lakes that seem very brown to your eyes. These normally occur because of decaying vegetation releasing dissolved organic material into the water. You may have seen this same brown-stained water on the streets or your driveway when dead leaves are wetted by rainfall in the autumn. Although lakes can appear to be very brown, they do not have more than a tenth of the dissolved organic matter as a cup of tea. [LSM note: The brown waters of Tahquamenon Falls in Michigan's U.P., as in this photo, is credited to the tannins from organic forest matter, just as John describes.]
Pink water. You may also see lakes with a shocking pink color if you travel in the Dakotas or other dry regions. Out on the prairie, sometimes the water that has become salty from evaporation contains a lot of sulfur. Purple or pink sulfur bacteria can live in this hot, salty water and these photosynthetic bacteria bounce back an apparent pink color to your eyes. If you leave your bird bath out in the heat of summer without changing the water you may have also seen these pinkish bacteria.
Reddish or red-brown water. Sometimes, too, along the south shore of Lake Superior, we see water that is deep reddish-brown. This is due to the erosion of iron-rich soil along the south side of the Lake. Because rock that was squashed by the glaciers is bouncing back and oscillating like a very slow trampoline, the south shore is now dipping, exposing more erodible soil to wash into the Lake. The iron-rich soil is red like rust because it is.
The color of water really matters to us all not only because it offers an endless variety of pleasing (or not pleasing) views. It matters also because the color determines the amount and type of light that feeds plants and animals in lakes and streams, ultimately determining the amount and diversity of lake ecosystems.
And Happy New Year, Too: Hillary Nelson and Sarah Holland, who both work at St. Luke’s hospital in Duluth, regaled patients with some holiday tunes on their violins Christmas Eve. The hospital posted a video of “We Wish You a Merry Christmas,” and chatted with Hillary, who summed up how song helps the hearer and the maker: “Music heals the heart. I needed that.” We all do, Hillary, and thanks for sharing joy.
Operation Taconite: Just before Christmas, the U.S. Coast Guard launched another version of Operation Taconite, the largest ice-breaking effort in the United States, to keep maritime traffic flowing on Lake Superior the St. Mary’s River, the Straits of Mackinac, Georgian Bay and all of Lake Michigan. The USCG cutter Biscayne Bay, based in Sector Sault Ste. Marie on the eastern shore of the Big Lake, traveled west to work deploy in Duluth, Superior and Thunder Bay. A video (seen here) shows the cutter passing Barker's Island in Superior. Another video posted gives a mini tour of what Sector Sault Ste. Marie does. The USCG cutter Alder, stationed in Duluth and also on ice duty, traveled the same route as the Biscayne Bay, returning recently after working to retrieve 81 buoys across 4,000 miles, all the way to Buffalo, N.Y.
Another Successful Operation: A Thunder Bay family won their own fantastic backyard hockey rink courtesy of Canadian Tire's "Operation: Puck Drop" program to keep hockey humming during the pandemic. "This year has forced many communities to put sports programs on hold," Canadian Tire posted with a video of the TBay rink. "So, for April and her two daughters, winning Operation: Puck Drop means a safe place to hone their skills, build friendships, and continue to play the sport they love – hockey. These girls won’t miss a single beat on the ice this year thanks to their new backyard rink." April Hadley, whose daughters Peyton and Leila love hockey, filled out the application that reflected a passion for hockey and desire for an outdoor rink; the application was chosen by judges from Hockey Canada. The Canadian Tire website, which has a video of the Hadelys' new rink, also offers instructions for how best to build you own backyard rink with a tool list of things to buy ... at Canadian Tire, of course.
Ole's Evinrude: Among the fond, but sad farewells to many enterprises we've made in 2020 is the discontinuing of Evinrude's outboard motor manufacturing in May. The Canadian-based BRP (Bombardier Recreational Products) which produced the brand said in its announcement that it would "focus on the next generation of propulsion" and promised continued support of the motors still in use. The invention designed by Ole Evinrude in Milwaukee in the early 1900s became known by his name and some were still made in Sturtevant, Wis. (The plant is being repurposed.) In its announcement about ending the outboard line, Evinrude posted: "For today, the sun has set on this unforgettable trip and we'll never forget our amazing customers and the adventures we've had. But tomorrow's a new day and the ingenuity of Ole Evinrude is still alive and well. Keep your eyes on the horizon!" Ole's invention got a nod from the American Society of Mechanical Engineers, which noted that while outboard motors existed before Ole's puttering in 1907, the heavy,
inconvenient creations weren't popular. "The landmark internal combustion, two-cycle Evinrude motor developed 1-1/2 horsepower at 1,000 rpm, weighed 62 pounds and used an engineering design that has remained the standard for outboard motors ever since," the ASME notes in naming the Evinrude in 1981 as a National Historic Mechanical Engineering Landmark. Legend has it that Ole (in this photo), picnicking with his future wife, Bessie Cary, and friends on an inland lake island one a hot August day, went to fetch Bessie the ice cream she desired and realized rowing was no way to travel with melting treat. The immigrant from Norway decided to find a better way to deliver. While the Evinrude outboard is gone, a motor lovers dreamland can still be found at the Freshwater Fishing Hall of Fame in Hayward, Wis. The hall of fame has outboards aplenty, like those beyond the canoe in this photo, along with lures, artifacts and our favorite gigantic muskie all on a 7-acre site. You'll find Ole mentioned there, too; he was inducted in 1980.
Our Adorable Assassins: The American martens spotted by trail cams on some of the Apostle Islands were mentioned in the Wisconsin DNR's recently released Natural Heritage Conservation 2020 Field Notes. "Trail camera and genetic research in the Apostle Islands show martens thriving and some animals dispersing to boost mainland Wisconsin populations; genetic testing confirms them as recent migrants from Michigan’s Upper Peninsula," the Notes note. Another Lake Superior notable in the publication are the Common Terns found on "a newly refurbished 'Ashland Tern Island,' an artificial structure at Bayview Park created in cooperation with Wisconsin DNR and is one of only two nesting colonies of Wisconsin-endangered terns in the Lake Superior basin. "Up to 150 pairs nest here annually," according to BirdCityWisconsin. A marten, you might recall, was our "cover girl" (or it might have been a "cover boy") when we ran the story about the resurgence of martens on the Apostle Islands in our December/January 2019 issue.
One for the Road (or the Highway H2O): We thought we'd leave you on this first day of the new year with an overhead view by Gus Schauer of the Algoma Compass arriving through the Superior Entry in Wisconsin into the Twin Ports. It's another reminder how the Big Lake ties together all shores on both sides of the international border. Let's hope the border itself opens soon so we can travel safely and gratefully Around the Circle.
Photo & graphic credits: Shannon Kivi/906 Images; Minnesota Sea Grant; Michigan DNR; St. Luke's; U.S. Coast Guard; Canadian Tire; American Society of Mechanical Engineers; Freshwater Fishing Hall of Fame; Wisconsin DNR; Lake Superior Magazine; Gus Schauer