A new study has concluded that invasive shrimps pose such a significant threat to native life forms in European rivers, as these organisms are no longer able to performs their roles in river systems.
The study focuses on Dikerogammarus villosus, an invasive species of shrimp which was able to replace the native Gammarus species found in European rivers. The change took place in the over three decades, and the process isn’t complete. The researchers observed a remarkable phenomenon: the presence of a predator in the environment could elicit what is known as the non-consumptive effect (NCE). The NCE will disrupt the regular effectiveness of the prey.
This means that the pray will spend a large amount of energy on the effort to escape potential threats as the self-preservation becomes more important than the fulfillment of tasks connected to the environment, including the shredding of fallen leaves into smaller fragments which can be consumed by other species.
Invasive Shrimps Threaten Native Life Forms in European Rivers
During the study, a species of Gammarus which is found quite often in the European rivers were placed in several tanks. Dikerogammarus villosus locked in cages were placed in half of the tanks. The team observed the activity of the Gammarus over several days as the researchers attempted to observe how the creatures were able to complete tasks similar to the ones found in their natural environments.
The results are quite fascinating. After four days the Gammarus species lost their shredding efficiency in the tanks were the invasive shrimps were also present. According to the lead researcher, the study proves that the biological invasions of voracious predators can lead to a major impact in the long run.
The Gammarus used in the experiment didn’t face such threats, and they didn’t know how to tackle the presence of the rival creatures. The study will allow other researchers to learn more about how NCEs can affect a specific ecosystem.
Andre Blair s is the lead editor for Advocator.ca. He holds a B.A. in Psychology from the University of Toronto, and a Master of Science in Public Health (M.S.P.H.) from the School of Public Health, Department of Health Administration, at the University of North Carolina at Chapel Hill. Andre specializes in environmental health, but writes on a variety of issues.