Septic wastewater is transforming suburban pond ecosystems

Residential areas and urban development may be having a bigger impact on the aquatic ecosystems than previously realized. It’s been known that agricultural and economic developments have caused habitat degradation and decreased biodiversity, however, new research has shown that residential land is transforming the food chain in ponds.

A new study has found that more and more animals and plants in suburban ponds are getting their nutrients from human waste.

The study was conducted by researchers from Yale University and Portland State University and published in the Canadian Journal of Fisheries and Aquatic Sciences.

The study complements previous Yale research that focuses on how fertilizers and human populations affect suburban ponds.

For the study, the researchers examined 18 different ponds in Connecticut and found that most of the animals on the food chain acquired nitrogen, an important nutrient for both plants and animals, from septic wastewater.

Not only did the results show that animals in suburban ponds got the majority of their nitrogen from human waste, but also that septic wastewater was fundamentally changing the nature of the food web.

Wood frog tadpoles, for example, changed their diet from fallen leaves to algae in suburban ponds.

“It suggests that tadpoles and other pond organisms are made up of human waste,” said Meredith Holgerson, a member of the research team.

Even though the researchers note that to the outside eye, the ponds seem to be in good condition,  the study proves the kind of impact suburban development has on the ecosystem.

“Our study highlights that, by choosing to live in and landscape particular places, human neighborhoods are creating fundamentally unique ecosystems by changing how water and food move around, and even what kind of food is available,” said Max Lambert, the study’s co-author. “Suburban animals behave, look, and function differently because of this.”

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By Kay Vandette, Earth.com Staff Writer