They would probably find high levels of fertilizer nutrients that the runoff introduces into the water. Unfortunately, the Everglades has been decimated by the effects of dams and canals which is a huge contributor to this runoff problem. Agricultural pollution adds phosphorous and nitrogen in high amounts to a water ecosystem that needs a balance of these nutrients. They can act as a fertilizer in the water, promoting algal blooms and plant growth. The increased flora takes oxygen away from the existing fauna and puts the balance of the ecosystem at risk.
