Effectiveness of a multipurpose artificial underwater structure as a coral reef canopy

Abstract

The following research focuses on artificial underwater structures (a.k.a. artificial reefs) in a coral reef environment to mitigate the natural and anthropogenic pressures which reef systems are increasingly facing worldwide. The research question is stated as: “Establishing a method to determine if a multipurpose artificial underwater structure (MAUS) can perform the functions of a natural canopy cover on a coral reef flat”. To investigate this research question both ecological and hydrodynamic parameters are considered. The MAUS selected for this investigation is composed of a canopy of 1000’s of interlocking synthetic hooks known as ground consolidators (GCs). This investigation employs both a physical and numerical model. The relevant parameters required to assess the research question can be found by obtaining the flow characteristics inside the canopy and wave induced hydrodynamic dampening across the canopy. Wave driven velocities recorded in a 1:5 scale GC canopy model are used to assess the success of larval recruitment. In addition to ecological considerations in the canopy, the bulk-wave height reduction is computed. This component allows for GC canopy design and schematization in a numerical model application. A link between the bulk wave-height reduction and internal wave driven velocities within the canopy is desirable to understand the connectivity of hydrodynamics and larval recruitment. The evidence collected in this study gives an indication of the GC arrangement which can provide a suitable climate for the establishment, and long-term vitality of a benthic community within its pore structure. This study is unique in that it incorporates various fields of research to bridge the gaps needed to present a more complete and comprehensive design guideline for GCs, and other MAUS concepts. Additional outcomes from this study include a more thorough oversight and understanding of the required changes and considerations needed to improve current interpretation of porous canopy media.