In early August, a massive algal bloom in Lake Erie prompted officials to shut down water supplies in Toledo, Ohio, affecting around 500,000 people. Residents and businesses were told not to use the tap water — for drinking, washing, or bathing. Now that the water is back on, the scare might seem like a thing of the past, but experts believe these harmful algal blooms (HABs) will be a regular occurrence in the future if we do not enact large-scale policy changes.
What It Means
Algal blooms result from eutrophication, the increase of nutrients in a given body of water. In many incidences of HAB-infested waters, the source of the increased nutrients is agricultural run-off. When pesticides and fertilizers used by farmers and homeowners do not get absorbed into the soil, they are left on the surface and transported to local waterways after rainfall. These pesticides and fertilizers leave an abnormally high amount of nitrogen and phosphorus in the bodies of water where they end up. Climate change also contributes to HABs, because warmer waters are a more hospitable environment for algae and higher storm intensity induces more fertilizer-tainted water run-off.
Under normal circumstances, the algae that make up these blooms satisfy an integral role at the bottom of the food chain, but can become quite harmful if the blooms become too massive. When the algae begin to decompose, they can create a zone in the water devoid of oxygen called a hypoxic area. The lack of oxygen makes it a dead zone, empty of aquatic life. Another negative aspect of some algal blooms is that they release toxins poisonous to humans and animals. Some known health effects of contact with the toxins produced by HABs include rash development, stomach and liver damage, respiratory damage, tumor growth, and paralysis.
What You Can Do
The most effective solution is prevention through source reduction. Reducing agricultural run-off is the single most important change we can make to diminish the scope of future HABs. We can reduce agricultural runoff a number of different ways:
- By reducing the quantity and frequency of fertilizer and pesticide applications. The fertilizers will be absorbed more completely, resulting in less run-off.
- By building retention ponds around fields to contain runoff. The resulting water can be reused to hydrate the field without polluting the surrounding water sources.
- By planting vegetation around the perimeter of fertilized fields to capture and utilize any runoff.
Unless you’re a farmer, you can’t really implement these measures, but you can be a voice of reason. Write to your local representative and tell them about the negative effects of agricultural run-off. Demand a change to the federal and state fertilization regulations. Look into local instances of HABs and inform your community. Be the source of positive impact, and perhaps in the future the water will remain safe for fishing, swimming, drinking, and maybe even a cannonball or two.