Species composition of Alcyonacea (Octocorallia) on coral reefs at Europa Island and associated connectivity across the Mozambique Channel

The soft coral fauna (Octocorallia: Alcyonacea) on reefs around Europa Island (Western Indian Ocean) were surveyed in 2016. The species richness was rather low for a protected, relatively pristine environment in the region. While certain ‘fugitive’ alcyonacean species were noticeably abundant, other soft corals were rare or absent. Since Europa Island is remote and isolated, connectivity was thus investigated with other alcyonacean communities in the Mozambique Channel by particle transport modelling. This revealed that, while the north-west coast of Madagascar appears well-connected with the northern Mozambique coast, the most likely source of soft coral recruits at Europa Island would be the Tulear region further south in Madagascar.