Foreign species are spreading across the Adriatic: Scientists are developing an early warning system ‘ALIENA’

Foreign or non-native species are organisms that have reached outside their natural range, most often by human action, for example by ballast water of ships or attached to their hulls. Not all foreign species are invasive, but the problem arises when they arise, spread and start to have a harmful effect on indigenous organisms, ecosystems or economic activities, according to the IRB.

“For example, if they consume the same food source, the native species have less of it, which is important for species such as small bluefish, a resource that has been used for centuries,” explains Dr. sc. Daniela Marić Pfannkuchen from the Center for Sea Research in Rovinj, Rudstroker Boškovi Institute.

Among the species that are studied as part of the ALIENA project is the sea walnut, a finfish originating from the western Atlantic that today also lives in the Adriatic. It feeds on zooplankton, an important link in the food chain, so its large populations can increase the pressure on food sources that local fish species depend on.

Scientists are therefore trying to determine where alien species appear, how numerous they are, and how and at what speed they are spreading. Early detection leaves the competent institutions more time to assess the risk and take appropriate measures, he said.

As part of the ALIENA project (ALIgning Efforts to control Non-indigenous species in the Adriatic sea), scientists and institutions from Croatia and Italy are working on a common knowledge base and a more coordinated system of monitoring foreign species in the Adriatic. Field observations are connected to computer models that estimate when environmental conditions favor the presence and spread of certain alien species.

The first version of prognostic tools older was developed, and the models are checked with data collected during pilot research in four areas in the Adriatic.

In research, molecular methods are also used to detect organisms that, due to their size, small number or similarity to other species, are difficult to recognize by traditional methods.

Marić Pfannkuchen pointed out that the discovery of species that had not been recorded before does not necessarily mean that they are new or invasive, because some may have lived in the Adriatic before, but could not be recognized using earlier methods.

Citizens can also participate in monitoring, and they can report photos of unknown or unusual marine organisms and information about the place and time of sighting through the Crafting the Sea application.

The ALIENA project is implemented within the Interreg Italy-Croatia 2021-2027 program, and its total value is EUR 2.62 million, of which EUR 2.1 million is financed from the European Regional Development Fund. Seven partners are participating in the project, including the IRB and the Institute of Oceanography and Fisheries.