Sea walnut invasive species spreading through the Adriatic Sea

The invasive sea walnut (Mnemiopsis leidyi), a translucent ctenophore originating from the eastern coast of North America, is increasingly appearing in the Adriatic Sea. First recorded in the northern Adriatic in 2005, experts from the Pula Aquarium report that the species has established stable, reproducing populations.

While traditionally viewed as a pest that consumes zooplankton, recent research indicates the species poses a threat to economically important shellfish by consuming their larvae. Environmental factors, including climate change and decreasing oxygen levels in the sea, may facilitate its spread by making it harder for natural predators to control the population.

Conversely, scientists are identifying potential benefits in the organism. Its tissues contain antimicrobial peptides, bioluminescent proteins, and other molecules that could hold value for biotechnology and medicine. Additionally, its evolutionary history makes it a significant model for studying animal development and the origins of the nervous system.