Hydrodynamics on Fringing Reef Systems with Spur and Groove Structures

Fringing coral reefs are the most common kind of coral reef systems, they represent around the 50% of the global reef area. Spurs and grooves (SAG) can be found on the fore reef and offshore of fringing reef systems down to a depth of 30m. They are composed of shore-normal ridges (spurs) where live coral grows, and separated by narrow channels (grooves) that usually are covered with coral rubble and sand. In recent years coral reef efficacy at dissipating wave energy has been highlighted as a very important ecosystem service of reefs and has received considerable attention. In contrast, SAG hydrodynamics research remains limited. It is therefore unclear how the SAG morphology influences wave energy dissipation and reef lagoon circulation. The objective of this work is to determine the effect of SAG morphology on wave dissipation processes and reef lagoon circulation patterns. The site of study is Xahuayxol, Quintana Roo (Mexico) in which depth differences between spurs and grooves can be up to 5 m , and can be spaced in the horizontal ~10m. Field measurements were carried out between the 27^th of November and 5^th December, 2018. Bathymetric, wave and currents measurements were taken using arrays of wave and current meters. Preliminary results of the field work show a complex wave transformation process where spurs and grooves seem to have a high influence on circulation and wave shoaling.