Campus News

UGA study: Species extinction can doom parasites

The effects of an animal population’s extinction may echo beyond the original species, new UGA research finds. Loss of a population could ultimately result in the extinction of parasites, which are critical for a healthy ecosystem.

UGA researchers focused this particular study on a Brazilian fish community and their associated parasites.

The study, published in Scientific Reports, which used publicly available data from a previous long-term ecological research study, looked at fish and parasite communities in a river in South America.

“We looked at how the loss of fish host species influenced loss of parasite species,” said the study’s lead author Tad Dallas, a doctoral candidate in UGA’s Odum School of Ecology. “Our goal was to consider the whole ecosystem and to consider overall biodiversity, which includes parasite species that require host species to survive.”

Previous extinction research has focused more on free-living species and less on the potential for the extinction of host species to cause further extinctions of parasite species.

Based on the study’s results, these secondary extinctions have major implications to the diversity of parasites and the structural stability of the host-parasite network.

Using the data, Dallas and co-author Emily Cornelius, a doctoral candidate at the University of Wisconsin-Madison, studied different scenarios that could occur in a community of fish, for example, removing species that may be larger or have a large number of parasites on them to get an idea of the effects it would have on parasite diversity and network structure.

The study found that these extinctions are, in a sense, a ripple effect, and the extinction of one could lead to the extinction of other important parasites. They identified key species from the group they were studying and then found that when key species go extinct, the network’s stability is compromised.

“The network is not just the fish community but is composed of the interactions between the fish and their associated parasites,” Dallas said.