Today’s post is a challenge because there are multiple storylines converging. As I’m writing, I’m thinking about you, my readers, and wondering which storylines you will find interesting because I find many things interesting that not everyone does! I’ve been hearing about the looming danger of Asian carp since getting involved in Great Lakes environmental advocacy, but I know this topic may not be as familiar to many of you. 

What are Asian carp?

The term Asian carp generally refers to four invasive species of carp: bighead, silver, black and grass. These species were brought to the southern United States from Southeast Asia in the 1970s to help control algae and weeds in aquaculture ponds and wastewater treatment facilities. However, both flooding and accidental releases of the fish allowed them to get into local waterways. They made their way quickly into the Mississippi River system and have now spread across much of the US, including the Illinois River watershed. They are now wildly overpopulated in many waterways.

In November, 2021, the Illinois Department of Natural resources announced that it was proposing a new name for Asian carp: Copi. There were two reasons for the proposed name change. One was that in the wake of the Covid-19 pandemic, anti-Asian sentiment had turned more vitriolic and there was a desire to shift from unfairly associating another challenging issue with Asian countries and peoples. The other reason was a marketing ploy to encourage people and the food industry to purchase more Asian carp for consumption, essentially as an invasive species control mechanism. I will note that both the name Copi and the fish appearing on menus have been slow to gain traction.  

Why are they a problem?

The primary threat from Asian carp is competition with native species for food. They eat native species out of existence given that some carp can grow to up to four feet in length and and 100 pounds. Given their size, which I know sounds insane, a secondary threat is boat and person safety in and on waterways when they are present. Notably silver carp are so physical that they come flying out of the water and can impact boat stability, safety and navigation. Watch the first 30 seconds of this video clip as illustration. 

How can we keep them out of the Great Lakes?

The Great Lakes Fishery Commission, the US Fish and Wildlife Service, and Fisheries and Oceans Canada all take the position that the only way to preserve the Great Lakes fishery is to prevent the introduction of Asian carp into the lakes. The focal point to prevent arrival are the waterways in Illinois leading into Lake Michigan. 

It’s now that I link us to my last post on the waterways around Chicago. Asian carp have been seen as close as nine miles out from Lake Michigan in the Chicago River and their DNA has been traced to even closer but they have not yet been documented in the lake. The most specific focal point for keeping the carp out is the Brandon Road Lock and Dam on the Des Plaines River. While there are currently mechanisms in place to prevent the carp from getting past this juncture, they are a semi-coordinated effort. There have been plans for a more extensive project in the state and federal assessment and pipeline phase for several decades. 

What’s the recent good news?

In June, the Brandon Road Lock and Dam project’s funding plan was confirmed and approved to the tune of $1B and construction will start soon. The states of Illinois and Michigan will share 10% of this cost. This is a very low state cost-share and is critically enabling the project to move forward. The federal government, specifically the US Army Corps of Engineers, will cover 90% of the costs. 

The project will include air bubble curtains, electric barriers and acoustic deterrents. I heard a description from an expert at the Alliance for the Great Lakes and it literally sounds like a crazy elementary age child’s brainstorm – First we smother the fish with bubbles! Then we zap them with an electric shock! Then we deafen them with horrific noises!

But a science fair project this is not. What’s at stake is the $7B Great Lakes fishing industry as well as the tourism and recreation industry of the region. Let’s keep our fingers crossed and recognize with appreciation this enormous effort from our federal government to protect Great Lakes waters and people. 

If this storyline interests you, I highly recommend this article from Detroit Free Press about the danger of Asian carp and the Brandon Road Lock and Dam project.

Over Labor Day weekend I accomplished another item on my Great Lakes summer intentions list. We were in Chicago for a family event but had a gap in the schedule Saturday afternoon and I made it to a Chicago area beach. We were in the northern suburbs so the closest beach was Tower Road Park and Beach in Winnetka. It was a beauty for sure. Colorful umbrellas and shade coverings dotted the wide swath of sand while boats puttered out into Lake Michigan from a nearby marina. There was a generous swimming area and playground on the beach.

Chicago’s size and expanse always impresses me whenever I visit. So much highway. So many surface roads. So many diners. There are just a heck of a lot of people living in and around the city (2.6 million in the city; 8.9 million in the metro area). All these people require a lot of built infrastructure to live, including clean water and sanitation systems. 

How Chicago managed to develop both of these for its growing population at the turn of the 20th century is one of the greatest engineering feats of its time. The flow of the Chicago River was fully reversed to prevent water polluted by industry and sewage from moving into Lake Michigan, which has always been Chicago’s drinking water source. I’m going to share the story this week because it’s incredible – but it also sets up my next post, which will be about one of the most important recent developments for the Great Lakes.

Prior to white settlers in the Chicago area, the Chicago River was a slow, somewhat unremarkable river that flowed through a soggy wetland. Two branches merged about a mile from Lake Michigan before flowing into the lake. In a twist of geographical fate, there is a ridge running north and south through what is now the Chicago metro area that created a subtle but crucial divide. Waters on the east side flowed east into the Chicago River and out into the lake and on the west side down into the Des Plaines River and eventually out to the Mississippi River and down into the Gulf of Mexico.

Starting in 1840 and extending through the Civil War, Chicago grew rapidly. Growing in parallel was Chicago’s enormous meat-packing industry. This industry contributed substantially to the pollution flowing into the river and out into Lake Michigan. By the 1880s, the situation was horrific. The river’s stench, drinking water contamination, and epidemics were constantly present. In 1886 a Citizen’s Association formed the Commission on Drainage and Water Supply. Eventually the Commission made several proposals to improve the situation, one of which was approved by the Illinois Legislature in 1889.

The proposal centered on building the Chicago Sanitary and Ship Canal. The canal would pull large amounts of water from Lake Michigan and, using a series of locks and dams, would shift the direction of the Chicago River, sending sewage out towards the Mississippi watershed while also creating a wider and deeper shipping channel that the Commission hoped might appease those downstream who were likely to be unhappy with the project.

The engineering required to build the canal throughout the 1890s is  beyond the scope of this post but it would not be too much to say that it was transformational. Equipment, tools and techniques developed in the process were replicated the world over, including in the construction of the Panama Canal. But the manpower required was also astronomical, and without question exploitative of recent immigrants and Blacks who were recruited or lured from the South to do the dangerous work. 

On January 2, 1900, a new century had dawned and with it came the initial intentional breach of a small dam holding water between the Chicago River and the new canal. It took two weeks for the canal to fill. On January 17, 1900, the controlling gates at Lockport, IL were opened, the Bear Trap Dam was lowered, and the river changed its course. The project had taken eight years from first shovel and had removed over 42 million cubic yards of soil and rock.

Technology can enable amazing things, like preserving drinking water for millions. But man-made solutions are not without environmental impacts, including sometimes wildly unexpected ones. Stay tuned for the next post to explore one directly related to the Chicago Sanitary and Ship Canal and the health of all of the Great Lakes.

Much of the content of today’s post came from a terrifically informative six-page write-up on the Chicago River’s history from the Metropolitan Water Reclamation District of the City of Chicago.

As a native of the Washington, DC area and relative urban and suburban life, until recently, my depth of familiarity with maritime life, resources and economies was truly slim. I will be honest in having a hazy understanding of the word fishery, hatchery, or what was meant when mentioning the work of fish management. While my knowledge is still not deep, I have learned much more through my Great Lakes exploration of the past three years.

Here is the mission of the Fish and Aquatic Conservation program of the U.S. Fish and Wildlife Service: We are committed to tackling the nation’s highest priority aquatic conservation and recreational challenges to conserve, restore, and enhance fisheries for future generations.

My lack of clarity around the word fishery is actually understandable. The word is used in a number of different, and sometimes inconsistent, ways. According to Wikipedia, Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place (a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish farms, both in freshwater water bodies (about 10% of all catch) and the oceans (about 90%).

Last post I shared about the infamous, massive alewife die-off of 1967 in Lake Michigan waters and shores. I ended with the question: What did they do about it?

In this case the “they” ends up being the Michigan Department of Conservation. And what they did was initiate one of the largest bioengineering endeavors of all time. States around the Great Lakes agreed to introduce coho and Chinook salmon from the Pacific Ocean into the lakes to bring the alewife population under control. It was a successful effort to redesign the Great Lakes fishery. Alewives were back to more controlled numbers by 1971.

Introducing salmon was the brainchild of Dr. Howard Tanner. In The Life and Death of the Great Lakes, Dan Egan writes a riveting chapter about Tanner – his environmental management expertise, his love for Michigan and the Great Lakes, his vision, and his streak of independent decision-making fostered by his time as a soldier in World War II.

As head of the Michigan Department of Conservation, he led the effort to introduce salmon in 1966. Biologists had already recognized the overpopulation of alewives by that time. Just one year later, by the fall of 1967, millions of salmon offspring appeared in Lake Michigan. The salmon grew large and heavy on the alewife diet. It created a frenzy of recreational fishing. Egan describes it memorably: “It was as if all the skiers in Michigan awoke one morning to find that their little hills had been replaced by the Rocky Mountains.” Recreational fishermen who had dreamed of one day fishing out West for salmon literally found them leaping out of the waters of Lake Michigan. Word spread of “coho fever”. Beyond successfully controlling the alewife population, the effort created a recreational boom in sport fishing and a new constituency of people invested in the Great Lakes. 

The Great Lakes have been known as a world class salmon fishery ever since. However, some danger signs have been flashing over the past thirty years. Nature constantly brings our attention back to cycles and interconnectedness – and sometimes seems to enjoy a little irony on the side. The alewife population is now dwindling.  And in dwindling, it may take the salmon with it given that they rely almost exclusively on alewives as their diet. That much despised little silver fish has been revisited, recognized, and respected for its role in the Great Lakes fishery.

In early July 2022 we drove to Northern Michigan to drop our older daughter off at summer camp for two weeks. For the weekend we stayed at a house about 25 miles east of Ludington. My husband and I drove up into Ludington State Park on the shores of Lake Michigan. As we drove in, gorgeous white sand dunes lined the road. It was early evening, so a transition time with beachgoers emerging from trails through the dunes, colorful umbrellas, chairs and towels in hand, headed back to their cars.

We parked and got out of the car to walk out on the beach. We were immediately greeted by what I can only describe as, frankly, a strong, unpleasant odor. Putrid is too strong a word, but it was fishy, and rotten. We walked over a dune path and emerged on the beach. The view was incredibly picturesque – gorgeous wide white sand beach and cottonball clouds. But a quick stroll closer to the water revealed the source of the smell – there was a band of dead, washed up small, silver fish stretching down the beach in both directions.  

These fish are alewives, and wash-up like this is, somewhat unfortunately, not an uncommon occurrence on the shores of some Great Lakes. The history of the issue is well-explained in Dan Egan’s book The Death and Life of the Great Lakes that I refer to time and time again. It’s a story of ecological imbalance.

River herring are a species well known to east coast North Americans for centuries. They hatch in the rivers flowing into the Atlantic and then head into saltwater for much of their life before heading back to the freshwater to spawn. 

River herring were first found in Lake Ontario in the late 1800s. It’s unknown how they got there – whether they made their way on their own through the St. Lawrence River or accessed it through the canals dug at the end of that century. For several decades they lived in some ecological balance as the Atlantic salmon and lake trout were natural predators. But once the evolving commercial fishing industry ramped up and overfishing of salmon and trout became an issue, the river herring became massively overpopulated. By 1931 they had been found in Lake Erie and by 1954 in the waters of all Great Lakes. 

The Great Lakes river herring quickly evolved to be a smaller, toothless version of the East Coast river herring. They lacked natural predators, and quickly came to dominate the fish mass of the lakes, especially Lake Michigan, where by 1965 they were likely 90 percent of the lake’s fish mass. By this point they had also come to take on another name – alewives. 

My dad was living in Chicago in the summer of 1967 when the city experienced the most infamous alewife happening of all time. There was essentially a massive die-off of alewives that dumped billions of fish carcasses on the shores of Lake Michigan around Chicago. 30 miles of shoreline were “smothered”, as Egan writes, by piles of decaying fish sometimes shin deep. The cost of management and clean-up in Chicago was pegged at $50 million – $350 million in 2017 dollars. The price tag across the entire summer and all the shores impacted: close to $1 billion in 2017 dollars. 

To most people, the die off was seen, and smelled, along the shore. However, in the water, there were reports of piles of carcasses at the bottom of the lake over 6 feet high and live schools of the fish were so thick that boaters described running into one being like running into a snowbank.

What happened?  

The reason turns out to be to be biological maladaptation. The fact that the alewives, originally saltwater fish, were able to live in the freshwaters of the Great Lakes didn’t mean that they were able to thrive. Their bodies simply didn’t work well due to the lack of salt. They experienced kidney stress, stunted thyroid activity, and an inability to handle the dramatic water temperature changes the Great Lakes can experience. But their mere survival had thrown Lake Michigan completely off-balance with no real predators to keep the population in check.

So what did they do about it? Stay tuned for Part 2 of the story in my next post. 

Photo from Whiting Robertsdale Historical Society

We’re going to pause from our Great Lakes tour for a post or two. Right after the new year, a number of you sent me this article from the Washington Post – or others on the same topic. The Great Lakes were in the news.

January 1st, 2024 recorded the smallest amount of ice cover over the Great Lakes in the past 50 years. Only 0.35% of the lakes’ surface area was under ice. The lakes average 9% for New Year’s Day. There is clear evidence of a downward trend likely due to climate change. Between 1973 and 2017, the lakes recorded as many as 46 fewer days per season frozen, which is defined as days when at least 5% of the lakes’ surface had ice cover.

There is variability year to year – 2019 was one of the highest ice coverage years on record (81% coverage at one point!), and things can also change through a season. Highest ice coverage is usually seen in February and early March.  

Why does this matter? The National Atmospheric and Oceanic Administration (NOAA) has provided a helpful answer.

There are several challenges to note. Thick ice protects the shoreline from erosion and flooding during winter storms. Animal patterns are disrupted, including those of fish who use ice for protection during their spawning season. Some areas of the Great Lakes have developed winter recreational seasons for things like ice fishing that depend on ice coverage.

But one of the main impacts of this shift for those living in the region is an increase in the well-known lake effect snow phenomenon. Lake effect snow occurs when cold air, often a front from Canada, sweeps across the relatively warmer waters of the Great Lakes. As it moves, warmth and moisture from the lake water rises into the lowest portion of the atmosphere. Because it is warmer and less dense than the cold air, it rises and creates clouds and snow.

Unfrozen lake is a prerequisite for lake effect snow. So, with less ice coverage at the start of January, the region was ripe for the impacts of lake effect snow, and we saw it in the middle of the month when a frigid front came through and we saw substantial snowfall.

For those of us living in the region, there is high variability with how lake effect snow is experienced. It can sometimes bring a light, innocuous, low density snow. But it can also bring strong bands of dense snow that can appear quickly, at times causing dangerous conditions for driving. Climate change and warmer temperatures will likely exacerbate the extremes causing punishing snows like those Buffalo experienced in the closing days of 2022 when between 50 and 77 inches of snow fell around the region.

In sum, climate change is driving a deep irony for the Great Lakes region. Warmer temperatures are moderating the climate overall, but increasing some of the most extreme winter weather that drives stereotypes and boastful declarations about the superior liveability of places like Florida and the Sunbelt. I encourage you to think critically about this sentiment though. Winters here can have some extremes but summers there have some extremes – and in some places dwindling access to freshwater. There is nowhere to escape our warming planet. We all have burdens to bear in the short and long-term. 

And, as I shared in one of my earliest posts about retreating from life on Lake Erie in the winter of 2021, the snow and ice can be mighty beautiful.   

Something happened last week that has not happened since 1968. A strike shut down 13 locks of the St. Lawrence Seaway between Lake Erie and Montreal trapping boats in the shipping artery and preventing others from entering on either end. 

Workers with Unifor, Canada’s largest private-sector union, walked out on October 22nd. They were in a dispute over wages with the St. Lawrence Seaway Management Corp. A deal was reached one week later on October 29th, but reflecting on the impact of the strike makes clear the under-discussed prowess of the Great Lakes economy.

The Great Lakes and the St. Lawrence Seaway carried over $12 billion of cargo in 2022; estimates were that the strike last week caused a loss of $100-110 million per day. On Wednesday, October 25th, Seaway management reported around 115 vessels that were stuck in the St. Lawrence river or Lake Ontario. Other vessels stalled included a U.S. Naval Warship, the littoral combat ship the USS Marinette, that sat in Cleveland’s port waiting to head into international waters.

This is a particularly busy time of year on the Lakes and Seaway given the fall harvest season. Of great concern was the hold-up of grain shipments that were headed to destinations around the globe. Grain shipments from the Great Lakes regions have been growing in recent years. In November 2022, the Great Lakes Seaway Partnership announced that grain shipments were up almost 25% from 2021. This increase is due in part to the war in Ukraine and changing climate patterns in other grain producing areas. 

An article in the Detroit Free Press last week during the strike reflected the wide economic impact: “We have grain that feeds the world that’s not moving. We have salt that goes on winter roads for safety that’s not moving. We have iron ore for steelmaking that’s not moving,” said Jason Card, spokesman for the binational Chamber of Marine Commerce in Ottawa.

While an article from Great Lakes Now reflected a very human position: “We want a fair and decent wage that shows the value our members bring. There’s a lot of labor unrest in North America right now and people are sick and tired of the ivory tower people getting everything while the rest of us get peanuts,” said Unifor spokesman John Hockey.

Economic interconnectedness reflects human interconnectedness. Human interconnectedness reflects the ways individual people understand how they, and their talents and labor, matter. May we always remain mindful of this as we navigate our daily lives and communities and ponder wider global dynamics.

Credit for all pictures today: pexels.com

Earlier this month the Alliance for the Great Lakes Ambassador program (of which I am a part), held a monthly “deep dive” session on environmental justice.

According to the US Commission on Civil Rights, environmental justice is: 

… the fair treatment of people of all races, income, and cultures with respect to the development, implementation and enforcement of environmental laws, regulations, and policies, and their meaningful involvement in the decision-making processes of the government.

The truth is that many people are not afforded access to safe and clean water from the Great Lakes and are not protected from the pollution that is a byproduct of the lake economies, or the adverse dynamics of the lakes and their waterways. Disproportionately affected are low-income communities and communities of color.  

Two storylines from Chicago starkly illustrate this reality.

The first is an opinion article on the Alliance’s website from 2019, “Flooding Hits Hardest in Chicago’s Communities of Color”. For a variety of reasons, many Great Lakes cities struggle with stormwater management. Flooding can bring any number of health or economic challenges to individuals already facing many. The article details flooding that occurs in the city’s Southeast neighborhoods during and after severe storms. Some of these neighborhoods are highly industrial and so floodwaters may bring toxic hazards as they run over Superfund and brownfields sites. 

For me, the statistics below speak for themselves: 

{In Chicago} Just thirteen zip codes represent nearly three-fourths of all flood insurance claims. Over three-quarters of a million residents live here – including 200,000 children and 100,000 elderly. Over a quarter of households are below the poverty line. And 93% are households headed by a person of color.

By contrast, seventeen Chicago zip codes had the fewest flood claim payments between 2007 and 2016 (less than one percent combined). Only 30 percent of residents in these areas are people of color.

The second storyline is one I heard though an interview on the Alliance’s podcast, Lakes Chat, in 2022. Oscar Sanchez is the Community Planning Manager with the Southeast Environmental Task Force.

In his role, Mr. Sanchez was part of a group of activists who fought the relocation of General Iron, a metal sheeting company in Lincoln Park on the north side of Chicago (General Iron has now rebranded as Southside Recycling). General Iron had a large number of violations including for air pollution and questionable operations. The local community (mostly white, more affluent) no longer wanted General Iron as a neighbor. Initially General Iron received support, including incentive funding, from the City of Chicago to relocate to the southeast part of the city (mostly Latino with surrounding Black neighborhoods, not affluent).

But the identified site for relocation was across from a park and a high school and down the street from an elementary school. The local community was a working one where it was hard for people to get involved as they managed day to day struggles. It was, as Mr. Sanchez said, hard for them to fight back, but people were scared. So a coalition of activists from across the community took on the cause. 

After the organized resistance, the city denied the original permit request from General Iron in 2021. This decision was a win for Mr. Sanchez and his local communities in their fight for environmental justice. The win remains a tenuous one; final decisions remain in limbo as General Iron moves their case through the courts (as of September 2023 news articles).

The heart of the matter sits with a question Mr. Sanchez poses in the interview regarding stark differences in city and regional planning and policy between the north side and south side of the city: 

Just because we are poor doesn’t mean we should be treated poorly…  If it’s not good for one community, why is it OK for a different community?    

It’s a worthy question that should be asked again… and again… and again.  

In an earlier post on the impact of climate change on the Great Lakes, I shared very real challenges that the Great Lakes and region will face in the years ahead. I closed the post foreshadowing this post on a different question: Will the Great Lakes be a climate refuge?

The International Economic Partnership estimates that 1.2 billion people will be displaced by climate change by 2050. In the United States, access to water is starting to impact growth in places like Arizona where earlier this year Phoenix had to slow housing construction due to lack of water resources. In the past 20 years over 5,000 people have been killed by major hurricanes. Tornadoes, heat waves and major wildfires have become routine events across the country. There will be a future of climate migrants, “climigrants”, driven to seek new places to live.

There are reasons that climigrants might choose the Great Lakes region:

1. Fresh water access. Sharing my often repeated fact: The Great Lakes hold 84% of all surface freshwater in North America.
2. Less extreme weather events than some areas of the country. The National Oceanic and Atmospheric Administration (NOAA) has an interactive natural disaster risk map that shows the Great Lakes region as remarkably free of threats compared with much of the country.
3. Moderating climate. Those famous, frigid Great Lakes winters? They still happen, but temperatures are rising and snow and frost days are declining. By 2050, average temperatures in the region are expected to increase by 3 to 5 degrees since 1951. The number of frost-free days increased by 16 days between 1951 and 2018. This National Oceanic and Atmospheric Administration (NOAA) page summarizes Great Lakes region climate change headlines.
4. At present, more affordable housing than many places in the US. According to Zillow, the average current home value in the Great Lakes region ranges from a high in Minnesota of $307,000 to a low in Ohio of $219,700. Most all Great Lakes states are ranked between 20th and 40th among US states.

There are also reasons that the idea of a climate haven or refuge might be too hyped:

1. Per my past post, negative impacts of climate change on the Great Lakes. And some threats may grow faster or differently than anticipated – e.g. this summer’s Canadian wildfire smoke.
2. Climate politics. This varies state to state in the region. Unfortunately, here in Ohio, policies from the current statehouse and governor have not been climate-friendly including a bill the governor jammed through in December 2022 redefining natural gas as a “green energy”.  
3. Decaying infrastructure. Drinking water, sewer and stormwater management improvements are needed in many places. Illinois and Ohio lead the list of states with the largest number of lead water lines still in use. Investment is needed in properties to make them livable and strategy needed to keep housing affordable proportional to regional jobs.
4. Economics. To attract new people who will stay, a wide range of job opportunities need to exist. Growing remote work opens up new avenues for some demographics but some Great Lakes economies remain fragile with the decades-long decline in manufacturing in the region.

I am grateful to live in this geographical region. There is an opportunity to attract a new generation of people seeking a stable, safe, livable place to settle. But for this to happen, there will need to be the vision, plan and political and popular will to prepare for it and reinvent ourselves and our way of living. I hope we find the courage to make this shift.

When we moved to Cleveland in 2014 and I saw Lake Erie up close, one of the things that took me by surprise was the color of the water. Standing on shore and looking out in the summer months, in many places the most visible stretch of water has a gorgeous blue color – it can be close to a turquoise. I’ve now seen this color in Lake Michigan, and memorably in Lake Superior, as well.

The color of Great Lakes waters varies tremendously of course – season to season, day to day, even hour to hour depending on weather and lake conditions. It can have a steel color, a deep green-brown, a dark blue.

But the turquoise, gem-like blue is something that many people notice and comment on – usually with enthusiastic disbelief.  People who grew up on the shores of the Great Lakes in past decades describe returning to one now and finding clear water in remarkable shades of blue. 

People flying cross-country might even notice it from an airplane. A cousin of mine flying between the west coast and New York City described looking out the plane window and being completely disoriented.  “We didn’t know where we were!  It didn’t make sense that we were above the Carribbean!”

I’ve been reluctant to share with people what I have learned about that bright turquoise blue.  Unfortunately, this striking color and clarity is not a sign of lake health as we would be inclined to think.  Instead, as Dan Egan writes in The Death and Life of the Great Lakes, it’s a sign that “the life is being literally sucked out of the lakes”.

A write-up from a 2019 segment on Chicago’s WGN 9 TV station summarizes a number of key points.

Many people think that water appears blue due to the sky. There is an element of light and refraction that can impact the appearance of a body of water. But it’s also the case that water radiates blue.

Water color is impacted by things in the water. Algae, decaying material and sediment can all be churned up in the water causing a color to shift. 

It’s also impacted by things not in the water. In the case of the Great Lakes, it’s the absence of healthy algae that used to be omnipresent in the water that has lightened or made many of the lakes “more blue”. The criminals in this storyline are the zebra and quagga mussels that arrived in the lakes sometime around the late 1980s and have since spread relatively uncontested. In a stunning statistic, scientists say there are so many mussels in Lake Michigan that they can filter the entire volume of the lake in four to six days, and they have reduced the amount of light-absorbing algae by over 50%.

So now when I look down into the lake and see clear waters and white sandy bottoms, I feel a tug of mixed emotions: a socialized response of what is thought to be beautiful waterscape and an ecologist’s gut feeling that all is not as it should be.