Hi, this is Zach. Annalise asked me to tell you some cool stuff about lakes and rivers, stormwater runoff, algal blooms, and floating plant islands.
So, here goes.
LAKES
People say amazing a lot. But lakes are really amazing. Compared to oceans, lakes are small players, but they have a big impact.
Our planet has millions of lakes. You can find them on every continent and in all kinds of environments. Many of them were formed by melting glaciers thousands of years ago. I live by Lake Michigan. It’s so big and stretches so far, it’s hard to believe it’s not an ocean.
Lakes and ponds cover less than four percent of the earth’s surface. That may not sound like a lot, but they have a crucial job. Carbon is an element that’s the basis of all forms of life on earth. Lakes cycle carbon between the surface of the water and the atmosphere, which helps regulate the earth’s global temperature and the amount of carbon dioxide in the air. Lakes also hold carbon in decaying layers of organic muck at their bottoms. They bury way more carbon than oceans do! And they provide a home to a wide variety of organisms, from plants to animals, fish, reptiles, and insects.
Lakes, like people, go through different life stages—being born, maturing, getting old, and finally (sadly) dying. All lakes, even the largest ones, will slowly disappear as their basins fill with sediment and plant material. This happens slowly, over hundreds or thousands of years. But with climate change, this process is speeding up. We are speeding it up. Warmer water, less ice in the winter, and flooding—all linked to global warming—are affecting every aspect of lakes.
If you’re a science geek like me and want to read more about lakes, visit National Geographic’s website (nationalgeographic.org/encyclopedia/lake) and ScienceDaily (sciencedaily.com/terms/lake.htm).
RIVERS
As with lakes, countless species of fish, birds, and other animals live in and along rivers. Rivers are part of ecosystems, which connect all the plants and animals in a particular area that rely on each other and the surrounding environment for survival. Many rivers feed into lakes, like Tru and Renn. Rivers are much more than what you see when you look at the surface of the water. They provide breeding areas for migratory birds. Fish spawn in rivers. And maybe most importantly, rivers give us drinking water! The majority of the water supply in the United States comes from rivers and streams, and the health of river ecosystems directly affects the quality of the water we drink.
Many rivers are being seriously polluted and/or depleted. I don’t have to tell you that breaks my heart. (More than Leo did.) (I’m a lot better now.)
Anyway, to learn more, visit americanrivers.org/threats-solutions/protecting-rivers/the-value-of-wild-river and nationalgeographic.org/encyclopedia/river.
STORMWATER RUNOFF
Runoff is the result of rain or melting snow flowing over sidewalks, streets, and driveways instead of being absorbed into the ground. The water picks up debris, chemicals, and other pollutants, which go into a lake or river. Runoff can do a lot of damage, making it difficult or impossible for plants to grow, destroying aquatic habitats, creating health hazards, and causing algal blooms. Oceans have been affected too. Red tides on Florida’s coast are harmful algal blooms that produce toxins. They’re happening more frequently and can last for a few weeks or longer than a year. One cause is runoff from nearby towns and farms. Many fish, birds, and sea animals, especially turtles, have died because of the tides.
We all contribute to the problem, and often we don’t even realize it. But we can change our habits. Be careful about what you pour down the sink. Compost yard clippings. Use a rain barrel to collect rainwater so it doesn’t wash into lakes and streams, or create a garden with plants native to your area that will soak up rainwater.
At Prairie Crossing School in Grayslake, Illinois, students raised money to replace concrete sidewalks with permeable pavement, allowing rain and snowmelt to go directly into the ground, decreasing runoff. Read about what they accomplished here: filterpave.com/prairie-crossing.
For more on what you can do, visit epa.gov/nutrientpollution/sources-and-solutions-stormwater.
ALGAL BLOOMS
I could go on and on about algal blooms and how worried I am about them. In the last few years, they’ve become more frequent in lakes and other bodies of water around the world. Scientists think this is related to warmer temperatures, heat waves, and other extreme weather events. The problem can be intensified by runoff, leakage from sewer systems, and other pollution.
Harmful algal blooms, also called HABs, occur in fresh water when blue-green algae grow out of control. A bloom doesn’t have to be toxic to be harmful to the environment. Blooms can kill wildlife and cause beach closures. Exposure to a bloom can be dangerous for people. Pets have a higher risk of getting sick because they’re smaller and may drink lake water or lick it from their coats.
If a bloom grows large enough, it can create a dead zone, covering the surface of the water and blocking sunlight, which affects species living below the surface. No oxygen gets through, and aquatic life disappears.
Scientists are studying algal blooms to figure out why they’re occurring more and what the long-term effects might be. Read more on the National Oceanic and Atmospheric Administration site (oceanservice.noaa.gov/hazards/hab) and the Wisconsin Department of Health Services site (dhs.wisconsin.gov/water/bg-algae/defined.htm).
FLOATING PLANT ISLANDS
Have you heard of something called allelopathy? It’s an incredible phenomenon! It’s when one plant influences the growth of another. Trees are a great example. Many use their roots to pull water from the soil away from nearby plants so the tree can survive.
This is what floating plant islands do!
The islands act as a wetland, which is a natural purifier, and clean up contaminated water. How cool is it that nature has a solution to that problem? A wetland marsh is like a giant pasta strainer. Power to the plants, right?
These islands help regulate phosphorus and nitrogen levels to improve water quality without the use of chemicals. Not only that, but the islands themselves provide a habitat for birds, reptiles, and other wildlife. In 2014, one company’s floating-island design was chosen by the US State Department as one of the top innovations in water technology.
The EPA (Environmental Protection Agency) is working with the Chemehuevi and Colorado Indian Tribes to study floating islands in Lake Havasu (on the border of California and Arizona) and the Colorado River, both located within the tribes’ reservations. The tribes identified native plants to use on the islands. Early results have shown promise—two months after launching the islands, the water’s nutrient concentration was reduced to a safe level. If you want to read more, visit epa.gov/sciencematters/epa-uses-floating-vegetated-islands-remove-excess-nutrients-water.
AND SO…
Each positive action we take will create a better future for everyone on this planet. I’m worried, but I’m also optimistic. Kids are taking charge and forming organizations to save our earth. Here are some I know of.
The teens behind Zero Hour (thisiszerohour.org) say that time is running out to address climate change issues. They’re marching, protesting, and raising awareness. You can become an ambassador in your community to educate and help come up with solutions.
Inspired by Greta Thunberg, a Swedish teen and climate activist who started Fridays for Future (fridaysforfuture.org), millions of students around the world participated in demonstrations in March and September 2019 to urge adults to act. Check youthclimatestrikeus .org for more info, including the movement’s platform to transition to 100 percent renewable energy by 2030, keep the water supply safe, and preserve public lands and wildlife habitats.
Another organization formed by young people concerned about climate change is iMatter (imatteryouth.org/campaigns). This group urges kids and teens to attend government meetings at the state and local level to push for changes such as reducing greenhouse gas emissions and stopping construction of new fossil fuel projects.
You, and I, and everyone can be heroes. And so can nature. It can help us. It has answers, if we just look hard enough. And listen.