VANCOUVER, Feb. 18 (Xinhua) -- Freshwater ecosystems emit a lot more carbon dioxide into the atmosphere when the animals at the top of the food chain are removed, a new Canadian study has found.
The recently published study, led by researchers from the University of British Columbia, was aimed at measuring the role predators play in regulating carbon emissions in order to better understand the consequences of losing these animals.
In the study, the researchers removed all the predators from three controlled freshwater ecosystems in Canada and Costa Rica and found 93 percent more carbon dioxide was released into the atmosphere.
Predators are bigger animals at the top of the food chain and their diets are comprised of all the smaller animals and plants in the ecosystem, either directly or indirectly, according to the researchers.
As a result, the number of predators in an ecosystem regulates the numbers of all the plants and animals lower in the food chain. It' s these smaller animals and plants that play a big role in sequestering or emitting carbon.
"We knew that predators shaped ecosystems by affecting the abundance of other plants and animals but now we know that their impact extends all the way down to the biogeochemical level," said Trisha Atwood, lead author of the study.
However, predators are disappearing from our ecosystems at alarming rates because of hunting, fishing and human induced changes to their habitats, which could have significant impact on climate change.
"People play a big role in predator decline and our study shows that this has significant, global implications for climate change and greenhouse gases," said Atwood.