[1] Analysis is presented of detailed observations of turbulence in stratified flow over topography. Key results are: 1) Directly measured dissipative energy losses due to skin friction and an internal hydraulic transition are relatively small, each accounting for approximately 10% of the mean flow energy loss, and 2) Production and dissipation of turbulent kinetic energy in flow over the topographic feature are in approximate balance throughout the transition from sub-to super-critical mean flow. The study is two-dimensional and a closed energy budget through direct measurement remains elusive; it is concluded that horizontal aspects of barotropic form drag such as eddy-shedding are responsible for as much as 30-40% of the mean flow energy loss. Citation: Inall, M., T. Rippeth, C. Griffiths, and P. Wiles (2005), Evolution and distribution of TKE production and dissipation within stratified flow over topography, Geophys. Res. Lett., 32, L08607,

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BackgroundCompared with a wealth of information regarding coral-reef recovery patterns following major disturbances, less insight exists to explain the cause(s) of spatial variation in the recovery process.Methodology/Principal FindingsThis study quantifies the influence of herbivory and water quality upon coral reef assemblages through space and time in Tutuila, American Samoa, a Pacific high island. Widespread declines in dominant corals (Acropora and Montipora) resulted from cyclone Heta at the end of 2003, shortly after the study began. Four sites that initially had similar coral reef assemblages but differential temporal dynamics four years following the disturbance event were classified by standardized measures of ‘recovery status’, defined by rates of change in ecological measures that are known to be sensitive to localized stressors. Status was best predicted, interactively, by water quality and herbivory. Expanding upon temporal trends, this study examined if similar dependencies existed through space; building multiple regression models to identify linkages between similar status measures and local stressors for 17 localities around Tutuila. The results highlighted consistent, interactive interdependencies for coral reef assemblages residing upon two unique geological reef types. Finally, the predictive regression models produced at the island scale were graphically interpreted with respect to hypothesized site-specific recovery thresholds.Conclusions/SignificanceCumulatively, our study purports that moving away from describing relatively well-known patterns behind recovery, and focusing upon understanding causes, improves our foundation to predict future ecological dynamics, and thus improves coral reef management.