Growth, Bleaching, Biodiversity & Ocean Chemistry
Coral reefs cover less than 0.1% of the ocean floor yet support 25% of all marine species. These living structures are built by tiny polyps that secrete calcium carbonate skeletons, powered by symbiotic algae called zooxanthellae. Explore how corals grow into branching, massive, and tabular forms; watch bleaching unfold as temperatures rise; see how ocean acidification dissolves reef foundations; and discover the intricate food webs, spawning synchronies, and ecosystem connections that make reefs the rainforests of the sea. Each simulation is grounded in real marine biology research.
How individual coral colonies grow, reproduce, and respond to environmental stress at the organism level.
Watch branching, massive, encrusting, and tabular corals grow in real time. Adjust light intensity and water flow to see how environment shapes coral form through accretive calcium carbonate deposition.
Raise ocean temperature past the 29°C threshold and watch zooxanthellae expulsion in action. Reactive oxygen species force corals to eject their symbiotic algae, turning white. Sustained heat causes mortality.
Over 100 coral species release eggs and sperm simultaneously, 3-6 nights after the full moon. Watch the lunar cycle drive mass spawning as gamete bundles rise through moonlit waters and fertilize.
The chemical environment that controls reef calcification, from pH to aragonite saturation.
The complex web of species interactions, disturbances, and feedback loops that determine reef health.
A Lotka-Volterra food web model: algae, coral, herbivorous parrotfish, predatory groupers, and crown-of-thorns starfish. Adjust fishing pressure, nutrients, and COTS larvae to trigger population collapses and recoveries.
COTS outbreaks cause half of all Great Barrier Reef coral loss. Watch starfish devour coral in real time. Control nutrient runoff (feeds larvae), fishing pressure (removes predators), and culling effort.
Fish migrate from mangrove nurseries through seagrass beds to adult reef habitat. Degrade any link and watch cascading effects: reduced fish biomass, increased sediment, and coral disease.
Reefs exist in two stable states: coral-dominated or algae-dominated. Push past the tipping point with storms, reduced herbivory, or excess nutrients and watch the irreversible phase shift unfold on a cellular grid.
Interactive tools to explore reef biodiversity and build your own reef ecosystem.
A living cross-section of a coral reef with 12 species across all trophic levels: parrotfish, tangs, urchins, clownfish, groupers, moray eels, reef sharks, and more. Hover over any organism to learn its ecological role.
Place branching, massive, and tabular corals, seagrass, rocks, fish, and urchins to build your own reef. Algae grows automatically on bare substrate -- maintain biodiversity and herbivore populations to keep your reef healthy!