Predictions of turbidity due to enhanced sediment resuspension resulting from sea-level rise on a fringing coral reef: evidence from Molokai, HI

The UW Sediment Dynamics group has been involved in the USGS Coral Reef studies on the Molokai, HI reef flat focusing on the evaluation of sediment-transport conditions, mechanisms, and impacts on depositional processes, and ultimately coral reef health. A specific goal of this work is to evaluate the sedimentary processes in light of projected sea-level rise. Discussion about effect of climate change on coral reef health and sustainability has largely focused on the effects of rising sea-surface temperature. However, increased sedimentation has also been correlated to coral stress and bleaching. The presence of suspended sediment may stress corals by reducing incident light levels, and moreover, particles that settle on coral surfaces interfere with photosynthesis and hinder feeding. The effects of increased water-surface elevation on coral reefs can be varied, and include increased circulation due to broader interaction with offshore water and changes in exposure to dissolved and particulate matter. Increased water-surface elevation will also change rates of erosion, resuspension and transport of terrigenous sediment on fringing reefs, and these impacts on turbidity are explored in this study.

Project publications:

Field, M.E., Ogston, A.S., Storlazzi, C.D. (2012) Rising sea level and increased turbidity on fringing coral reefs. EOS Transactions, AGU, 93, 23.

Ogston, A.S., Field, M.E. (2010) Predictions of turbidity due to enhanced sediment resuspension resulting from sea-level rise on a fringing coral reef: evidence from Molokai, HI. Journal of Coastal Research 26; 1027-1037.

Presto, M.K., Ogston, A.S, Storlazzi, C.D., Field, M.E., (2006) Seasonal variation of sediment transport on a fringing reef. Estuarine, Coastal and Shelf Science 67: 67-81.

Ogston, A.S., Storlazzi, C.D., Field, M.E. and Presto, M.K. (2004). Sediment resuspension and transport patterns on a fringing reef flat, Molokai, Hawaii, Coral Reefs 23: 559-569.

People:   Andrea Ogston