The Caulerpa cylindracea is an invasive algae of Australian origin that, with a growth of more than a centimeter per day, can form large tracts of tapestry preventing oxygen from spreading into the sediment, being a threat to the infrared communities of photophile algae and marine fanerogam. In addition, it can cause impacts on the deeper communities of maërl and coralligen, impacting on the ecosystem and affecting fishing activity and underwater tourism.

The last few weeks have featured in the press and social media different headlines reporting and alarming about its presence in the Parc Natural de Cap de Creus. By way of example, we cite two:

– (July 19th, 2022) “An invading alga is unaware of the alarm in the natural park of the Cap de Creus.” Crónica Global/El Español.
– (July 19th, 2022) “Detected in the Catalan playas an invasive alga jeopardising the marine ecosystem.” Nius Diario.

However, it is important to note that in 1990 the Caulerpa cylindracea was already observed in the Mediterranean. We have known about its presence in Spain since 1999, when it was mentioned in the Bay of Palma. In peninsular waters it was first detected in Alicante in 2000.

In Catalonia it was first seen in 2008, when SUBMON collaborators participated in the monitoring of the quality of Vilanova i la Geltrú posidonia. Since that time it has been observed along the Catalan coast, year after year. In 2016 at the Marine Reserve of Ses Negres in Begur, in 2017 at the beach of Canyelles Grosses, in Roses and in 2019 it was already in areas like Cala Galladera on the Cap de Creus.

The eradication of this alga is only viable when it has colonised small areas. The management measures recommended by experts are based on preventing their spread by limiting the anchoring of vessels, bathing, diving and fishing activities in areas where this invading species is present.