Modelling how corals apply the Goldilocks Principle to engineer their habitat
Item statusRestricted Access
Embargo end date10/03/2023
The importance of the growth, proliferation and longevity of reef-forming cold-water corals is paramount as they support various complex bio-diverse habitats and provide many essential ecosystem services. These cold-water coral reefs consist of layers of living coral tissue that grow above large masses of coral skeleton. Here, the Goldilocks Principle is used to promote growth in `just right' conditions and model how cold-water corals engineer their habitat in order to slow down incoming ows that are usually an order of magnitude higher than the optimal ow conditions for catching prey. The growth and death of the simulated coral colonies depend on the dynamically changing energetic reserves and the ability of the coral particles to store energy in optimal conditions. A further improvement on this model is the introduction of a `nutrient rule'. With this added condition, coral growth now depends not only on hydrodynamics but nutrient availability as well. This new rule allows investigations of how coral particles within a colony compete for the available resources or even how multiple colonies compete among each other for the nite nutrient resources. The model is then used to investigate the threat that cold-water corals face due to ocean acidi cation and the ever-shallowing aragonite saturation horizon. In these more acidic conditions coral prosperity becomes more di cult, as coral skeletons can be dissolved in aragonite under-saturated waters; that can potentially lead to a net loss of reef accretion. Modelling the mechanisms behind coral skeleton dissolution in various acidi cation scenarios is a helpful way to visualize the e ect of ocean acidi cation to cold-water coral reefs and help determine reef recovery times and conditions. Finally, the model evaluates restoration practices for cold-water colonies. The computational uid dynamics model is based on the Smoothed Particle Hydrodynamics method, a mesh-free Lagrangian numerical method. It is written in the C++ programming language and parallelised with OpenMP to improve its e ciency and reduce the execution times.