Primary colonization and early succession stages in the recent marine lava deltas of La Palma (Canary Islands)

Resumen

In September 2021 a volcanic eruption started in La Palma (Canary Islands), lasting for almost 3 months. During this episode, several lava flows reached the coast, creating two lava deltas with a total surface area of about 50 hectares, and reaching depths of over 100 meters in some points. In this study, we have followed the primary colonization and early succession of fishes, invertebrates and macroalgae in these new and morphologically complex intertidal and shallow subtidal environments. In general, the new lava deltas are still significantly different than the control areas, but community response has been different in the three groups and two environments (intertidal and subtidal) studied in terms of species richness and abundances. Fishes rapidly colonized the new areas, and have similar richness and abundances to the control zones after only seven months of monitoring. Invertebrates have shown a continuous increase in abundance and richness, still lower than in the control areas, and at different rates in both intertidal and subtidal. Macroalgae quickly covered almost 100% of the available substrate in the intertidal, with a distinctly lower cover in the subtidal, and richness has been in continuous fluctuation marked by the succession of seasonal species.