Sediment and water quality in American Samoa

Funding agencies:  NOAA Coral Reef Conservation Program, National Fish and Wildlife Foundation, American Samoa Department of Commerce.

Alex Messina measuring sedimentation on reefs in American Samoa

Sediment and nutrient loading impacts the health of coral reefs.  This series of projects funded by NOAA and NFWF quantified the sources of sediment in a watershed draining to a sediment-impacted reef, and documented the impact of mitigation activities on sediment load. Since 2012, we have monitored stream discharge and sediment loading, with a particular focus on a highly-disturbed watershed (Faga’alu).  Monitoring included a pre- and post-mitigation effort, and ongoing work is documenting the impacts of mitigation on sediment loading and coral reef condition.


Biggs, T.W., Messina, A.T., Rice, S.H., Hattori, M.C., McMillan, H., 2023. Separating impacts of storm characteristics and mitigation activities on suspended sediment: Implications for sampling to evaluate mitigation success. J. Hydrol. 130525.

Holst-Rice, S., *Messina, A. T., Biggs, T. W., Vargas-Angel, B., & Whitall, D. (2016). Baseline Assessment of Faga’alu Watershed: A Ridge to Reef Assessment in Support of Sediment Reduction Activities and Future Evaluation of their Success. Silver Spring, MD.

*Messina, A. M., & Biggs, T. W. (2016). Contributions of human activities to suspended sediment yield during storm events from a small, steep, tropical watershed. Journal of Hydrology, 538, 726–742.

Storlazzi, C. D., Cheriton, O. M., *Messina, A. M., & Biggs, T. W. (2018). Meteorologic, oceanographic, and geomorphic controls on circulation and residence time in a coral reef-lined embayment: Faga’alu Bay, American Samoa. Coral Reefs.

Dataset on discharge, turbidity, and suspended sediment concentrations, 2012-2016:

NOAA Story on Faga’alu watershed here.

* indicates student co-author