Does it seem like you’re reading more and more headlines about algal blooms, dead zones, and water crises across our country? Here’s why
Water is always moving. The Lake Erie waters dripping off a just-landed walleye contain billions upon billions of molecules that traveled untold miles over time, picking up all kinds of chemical hitchhikers, which include nutrients—nitrogen and phosphorus—from farm fertilizer. The word “nutrient” is often associated with positive effects on human health, but they can become dangerous pollutants in our watersheds.
In 2016, the Environmental Protection Agency released a memo renewing a single call to action: reduce nutrient pollution. Why? Because it “remains one of the greatest challenges to our nation’s water quality and presents a growing threat to public health and local economies.” In other words, nutrient pollution makes our water toxic to drink and costs communities millions of dollars to treat.
Nutrient pollution comes from many sources, including storm runoff from cities, but a lot of it drains into our water via poorly managed agricultural land. Nutrients in fertilizers make farms more productive, but when rain washes over those fields, nutrients can pollute entire watersheds. The Des Moines Water Works lawsuit, which was perhaps the biggest legal action on water quality in decades, specifically addressed pollution caused by nitrogen, one of the major components of fertilizer. The downstream impacts are bad for human health, sportfish, waterfowl, and even your Labrador retriever.
While the nutrients themselves can be toxic, the effects of added nitrogen and phosphorus can ripple out with devastating effects. Nutrient pollution leads to algal blooms, which decimate fish and wildlife populations not only near the agricultural lands where nutrients are sourced, but also downstream at some of the best freshwater fishing, saltwater fishing, and hunting spots—on both private and public lands and waters.
That’s why sportsmen and women should care deeply about this problem and work with landowners to support solutions.
What’s Feeding the Beast
Nutrients facilitate algae growth, just like fertilizer on a farm facilitates crop growth, and the algae need little else to survive. While there is typically more than enough light and water to keep algae reproducing, the presence, or lack, of nutrients in water is the limiting factor keeping algae populations in check. Reduce nutrients and growth stops. Add them, and growth explodes uninhibited.
The critters that we love—fish, ducks, and more—thrive in conditions with low levels of algae. When we add fertilizer to the equation, everything gets out of whack, and resulting algal blooms become a big, big problem. Here’s why:
First, and most simply, some types of algae are toxic if consumed by fish, wildlife, and humans. When these toxic algae bloom, they can create dire scenarios for public health. This has led to states of emergency in cities and towns across the country, including parts of Florida, the Great Lakes, and Utah. In 2014, half a million residents of Toledo, Ohio, were banned from drinking the city’s water, or using it to cook or brush their teeth, for three days. Similarly, algal blooms are also toxic for fish, wildlife, and pets (including your bird dog) and can cause massive die-offs.
Second, algal blooms lead to a depletion of oxygen. As algae dies it decomposes, and the business of decomposition requires a lot of oxygen. All that oxygen consumption leads to hypoxia, the absence of dissolved oxygen in water, which causes sportfish such as trout and salmon to literally suffocate. This is what’s happening in the Gulf of Mexico and Chesapeake Bay dead zones.
Third, mats of algae block sunlight from entering the water, harming aquatic plants by limiting their ability to convert sunlight into energy. This causes vegetation to disappear from wetland and coastal areas, removing an important food source for fish and waterfowl and a source of oxygen that is urgently needed in water where algae are decomposing.
All of this is to say that when you read or hear about clean water initiatives, you should be as concerned as you would about a threat to your public access, because toxic water means losing opportunities to hunt and fish. And when you think about conservation, remember that watersheds often start on private lands and that landowner conservation practices—like restoring wetlands, maintaining stream buffers, and planting cover crops—are critical to maintaining healthy fish and wildlife habitat.
Farm Bill Solutions
The Farm Bill supports some of the most successful programs for improving water quality and reducing harmful nutrient runoff from private lands. For example, the Regional Conservation Partnership Program was introduced in the 2014 Farm Bill partly to allow landowners to partner with organizations to improve soil, water, and wildlife habitat conditions. Click here to learn more about the farm bill conservation programs that help landowners improve water quality downstream.
This was originally posted October 12, 2016, and has been updated.