Lithophyllum monitoring

Lithophyllum byssoides, also known as the seashore lithophyllum, is a small encrusting red algae that lives in the Mediterranean and the Atlantic on rocks in the surf zone. It is a protected species, listed in Annex I of the Bern Convention and Annex II of the Barcelona Convention, as it is highly threatened by pollution, particularly hydrocarbons.

With its rigid appearance due to its calcareous skeleton, it forms colonies that, over time, can create structures several tens of centimeters in size, known as Lithophyllum rims.

Lithophyllum byssoides rim © Samuel Jeglot - NaturDive

In Monaco, several colonies are found in the Larvotto Marine Protected Area on rock formations near the surface. They are monitored since 2023 by the AMPN and Dr. Alexis Pey from the Thalassa Marine Research & Environmental Awareness consulting firm to track their development and propose appropriate management measures.

Close-up of a Lithophyllum byssoides colony © Camille Devissi - AMPN