Reef spawning in the SeaSim

A close-up of branching coral with extended tentacles from individual polyps. 

The National Sea Simulator supports the successful propagation of a range of marine organisms including coral, sponge and crown-of-thorns starfish.

  • With specialised infrastructure, SeaSim is able to replicate in situ spawning conditions in an experimental setting.
  • Ideally located adjacent to the Great Barrier Reef (GBR), the SeaSim also has ready access to reproductively fit specimens.

Collectively, SeaSim’s unique facilities and location provide unprecedented opportunities to undertake rigorous and innovative experiments that examine reproduction and the early-life history of marine invertebrates.    

See our spawning research activity page for the latest spawning activities in SeaSim.

Coral Spawning

Coral mass spawning is an annual natural phenomenon where multiple species of corals synchronise the release of sperm and eggs over several days following the full moon. For example, along the Great Barrier Reef spawning usually occurs after the full moon in October and November.

During spawning, the coral sperm and eggs float to the surface of the ocean, fertilise and then develop into larvae. The larvae eventually settle on the reef, creating new coral colonies. The spawning and larval phase of corals is a key event for the production of future coral generations and the replenishment of coral ecosystems.  

It is during these very narrow windows of opportunity that researchers have the capacity to collect samples of coral larvae and study the reproductive biology of broadcast spawning corals.



SeaSim’s coral spawning success

Each year, around ninety coral colonies from numerous different species successfully spawn in the SeaSim, producing approximately five million larvae. Sophisticated larval rearing facilities and dedicated settlement systems allowed for the mass settling of up to 50,000 larvae per day on experimental substrate. State-of-the-art experimental facilities enable these larval and juvenile corals to be used in a variety of manipulative experiments looking at impacts such as climate change and ocean acidification.


Spawning activities and collaborative opportunities

Along with AIMS researchers and students, SeaSim attracts national and international collaborators. Researchers travel from all over the world to work in the SeaSim during the Great Barrier Reef coral spawning season.  Scientists from a range of institutions work independently or alongside AIMS staff, contributing to a number of high-profile projects that seek to:

  • understand how climate change impacts the health of juvenile and adult corals and sponges, as well as the inheritance of temperature tolerance;
  • attempt to enhance coral resilience;
  • conduct experiments that examine the effects of dredging sediments, water quality and climate change on coral reproduction and their early life stages;
  • develop new tools for conservation and restoration, including extending the GBR coral cryo-repository; and
  • investigate food requirements of crown-of-thorns starfish in order to understand why these animals have destructive outbreaks.

For additional project details, please visit the SeaSim spawning activities page.

For more information about SeaSim, please contact:

Craig Humphrey
SeaSim Precinct Operations Manager

Download the National Sea Simulator booklet (PDF | 1980KB)

SeaSim uses smart technologies to replicate in situ spawning conditions.

Engineered substrates, called coral plugs, are prepared well in advance of the spawning event and create the substrate onto which coral larvae can settle.

AIMS' research vessel, R/V Cape Ferguson, takes AIMS staff to reef locations for the collection of reproductively fit specimens.

Expertly trained divers carefully collect corals from the reef.

Coral specimens are moved from the R/V Ferguson and taken to the SeaSim to spawn. After spawning, the colonies will be returned to the field, used in experiments or become part of the long term coral holdings at the aquarium facility.

Reproductive fragments of corals are collected in the field and used for spawning experiments at AIMS. Some of the spawning corals have been previously tagged.

Post-doctoral researcher, Dr Heidi Luter and PhD student, Katharina Damjanovic undertake experimental coral spawning at SeaSim. Coral colonies are isolated and observed with red lights so as not to disturb spawning behaviour. Released spawn is collected from the surface of the tanks and used in experiments.

Freshly collected coral spawn used for experiments at AIMS.

SeaSim’s dedicated spawning and rearing facilities support innovative research projects. Here, Technical Officer Natalie Giofre examines freshly collected coral spawn in the SeaSim larval rearing room.