Harvesting wild coral spawn slicks. Photo by Chris Doropoulos
Enhance coral reproduction and recruitment on recovering reefs, following disturbance
Assisted transfer of coral larvae
Small (a few hectares, a single reef) to medium (20 or more reefs)
Coral seeding aims to speed the return of coral cover to a disturbed or damaged reef by increasing the number of available coral larvae for natural settlement, particularly where the reef has a low larval supply (e.g. following a large-scale bleaching event).
This potential intervention involves capturing natural, seasonally produced, coral spawn/larval slicks into tanks and transporting them via large vessels for release to help reseed local or regional high-priority reefs.
The aim is to increase the number of corals from the spawning slick that ultimately recruit into reef populations.
Harvesting wild coral larval slicks is likely to have a minimal negative impact on Reef ecology, as the mortality rate of the larvae in a slick is typically high.
Compared with re-seeding just a few species, it offers the potential to capture a diverse range of species and allow the re-establishment of reef communities.
While coral spawn naturally travels long distances between reefs, assisting the transfer of wild corals would require measures to ensure the introduced corals did not harm the local population.
Image courtesy of Doropoulos et al, Testing industrial-scale coral restoration techniques: harvesting and culturing wild coral-spawn slicks. Frontiers in Marine Science, 2019