Standard Presentation (15 mins) Australian Marine Sciences Association 2022

Colouring coral larvae for tracking mass larval deployments for reef restoration (#318)

Christopher Doropoulos 1 , George Roff 1
  1. CSIRO Oceans & Atmosphere, St Lucia, QLD, Australia

As coral reefs degrade, understanding patterns of coral connectivity is of increasing importance. Restoration interventions that deploy larvae en masse to increase broodstock are one of the most promising interventions for large-scale and ecologically relevant restoration. Yet, predictive models of coral dispersal that identify source-sink dynamics are often unvalidated, and restoration approaches that utilise larval deployments have yet to identify whether cultured larvae settle close to release sites. To overcome these limitations, we adapted classic cell-staining methods and applied them to developing larvae from six phylogenetically and functionally distinct broadcast spawning coral species. By refining incubation times and stain concentrations in a series of lab experiments over a two year period, we optimised the staining procedure to minimise the impact on larval survival and settlement. We then applied the staining method to wild-sourced coral larvae from multi-species coral spawn slicks to field validate the process from staining through to releasing and detecting larvae on reef substrates. Our approach is rapid, simple, effective, and cheap, making it suitable for remote field locations and to scientists and practitioners from developed and developing nations.