Freshwater ecosystems will emit much higher amounts of carbon dioxide in the atmosphere if the main predators are removed from the food chain, a study published today in Nature Geoscience reveals.
Trisha Atwood, the lead author of the study and a PhD candidate at the Department of Forest and Conservation Sciences at University of British Columbia, warns that hunting and fishing practices could introduce irreversible changes to the predators’ habitats.
The aim of the study was to establish and estimate the role of these animals in the regulation of carbon emissions. Since their main diet includes all the smaller plants and animals in the ecosystem, the scientists wanted to understand better what could be the possible consequences if the habitats are lost.
The results indicate that big animals not only regulate the population of their prey, but they also indirectly control the carbon cycle. The small animals and plants are these responsible for the sequestration or emitting of carbon. The scientists conducted an experiment in which they removed predators from three freshwater ecosystems. They observed a 93% increase in the released carbon dioxide.
According to Atwood, the main threat to predators is the humans. With our daily practices, we directly or indirectly affect the abundance of other plants and animals, because we reduce the population of the bigger ones.
The study proves that the impact could be much higher and its strength can be noticed even at biochemical level.