I don't know about you, but I can't believe summer is just around the corner. I feel like I'm still getting out of my winter slump (or maybe that's just my junioritis kicking in). And with the warm weather finally settling in for good, Lake Mendota is open for business. But how safe is the water actually? Do you really know what you're swimming in?
Whether you're from Wisconsin or not, farms around here are a familiar thing. The problem begins when farmers use artificial fertilizers on their crops that are grown for food production and cattle feed. These fertilizers are full of nitrogen and phosphorous, two important nutrients for crops. When these elements are in excess, they can have devastating effects on water systems. After these fertilizers have been absorbed into the soil, rain runoff picks them up and drains straight into our beloved lake. And it's not just farm fertilizers. It's from residential lawns, Bascom Hill and urban parks. All the excess phosphorous that is finding its way to Lake Mendota is screwing with the ecosystem's balance.
A direct link has been found between excessive phosphorous and increased algae growth, a process called eutrophication. Eutrophication causes whole lakes to be swallowed up by cyanobacteria algae. And algae create bigger problems than just being icky to the touch while you're swimming. Cyanobacteria cover whatever they find—boats, piers, shorelines—and smell terrible. They also cause problems in the drinking water by changing its taste and odor. And when algae die off, they create an oxygen shortage in the water, killing off many species of fish and bottom-feeding organisms. These oxygen-poor areas are called dead zones, and they are showing up all over the world in freshwater systems and coastal zones, like the Gulf of Mexico, causing damage to ecosystems and fisheries.
Global warming is just adding more fuel to the fire; algae thrive in warm temperatures. So while other species may die off from intolerance to temperature change, algae will prosper. There are even some strains of algae that are toxic to human beings. In fact, Dane County can claim the first person ever killed by toxic algae, in 2002. Thankfully hardly anyone dies from algal contamination, but serious rashes, hives and throat and eye irritations are common. So please, if you must enjoy Lake Mendota up close and personal, shower off afterward. You'll thank me later when you're the only one without a rash.
Nitrogen plays a role too. While phosphorous is responsible for extreme algae growth, nitrogen has been found to have a role in the greenhouse effect, smog pollution and overgrowth of weedy plants (including invasive species) and have adverse effects on human health via air and water pollution. So the take-home message is, we can't just get rid of one or the other. We need to limit the use of both, meaning artificial fertilizers altogether, on farms, residences and public grounds.
Some first steps were taken this past March when Dane County officials wrote up a report calling for the Obama administration to take note of the seriousness of this problem. They are concerned about increasing health issues as the amount of concentrated phosphorous rises in our Madison lake system. Certain fertilizers have been banned, and a program called Yahara CLEAN is in the works. While the increased attention is a beacon of hope that once again we might experience a safe Mendota, the problem isn't necessarily new phosphorous entering the system anymore, it's the already existing phosphorous. And the cheapest ways to clean up the lake, while poisonous to the algae, are also poisonous to everything else. Whether we're ever going to be able to solve this problem for good is debatable.
Unfortunately, with the disappearance of our wetlands, nature's waste treatment plants, the problem may only increase. With no natural barrier between the contaminated runoff and the lake system, there is no other natural stopping point for the excess nutrients. Nature had a clear design in mind, but humans are about being cheap and efficient, and unfortunately we are seeing the aftermath now. If we want clean water to enjoy for generations to come, we need to make large changes.
Samantha Egelhoff is a junior majoring in zoology with a certificate in environmental studies. We welcome all feedback. Please send responses to opinion@dailycardinal.com.
