Project Impacts

1. Developed robust predictive algorithms to relate in situ water quality parameters (phycocyanin, colored dissolved organic matter (CDOM), and suspended particulate matter (SPM)) to remotely sensed reflectance data collected with unmanned aerial systems (UAS). Algorithm estimates for cyanobacteria (via phycocyanin), CDOM, and SPM were consistent with lab measured water samples.


2. Evaluated geologic controls on the location of submarine groundwater discharge (SGD) and resulting modification of water quality parameters proximal to oyster reefs in Mississippi Sound through the collection and synthesis of seismic and isotopic tracer data.


3. Synthesized seismic survey data results indicate the presence of a complex network of Pleistocene paleochannels cross-cutting the study area. The paleochannels exhibit relief ranging from 10-15 m as well as widths ranging from 0.3 – 2 km and are infilled with geophysically distinct sediments.


4. Synthesized an extensive database of archived and newly collected seismic reflection profile data as well as archived core data in order to characterize the structure of the Pleistocene-Holocene unconformity surface under the western Mississippi Sound.


5. Isotopic tracer data indicates that SGD is an active process in the study area but that it is not spatially correlated with paleochannels or oyster habitat. In conclusion: (1) The inverse relationship between SGD concentration and distance from the shoreline is commonly observed and suggests that SGD may be sourced from unconfined coastal aquifers, (2) the shore parallel orientation of the observed paleochannels is not commonly observed and suggest that the eastward prograding St. Bernard lobe of the Mississippi River delta may have exerted a degree of influence on later Holocene surface drainage patterns in the study area, and (3) the morphology of the larger paleochannels suggests MBRACE Core Research Program 1 Summary Report | 8 that they evolved from fluvial to estuarine environments as the Holocene transgression submerged and reworked them.


6. Created benthic habitats maps of seabed sedimentary characteristics proximal to oyster reefs in Mississippi Sound through the collection and synthesis of physical samples and acoustic reflectivity data. Variability in backscatter intensity across the surveyed area was associated with substrate classes defined as oyster shell, mud dominated sediment, and sand dominated sediment. High resolution imagery of the bed clearly shows well defined areas of oyster shell, mud dominated sediment, and sand dominated sediment. These interpreted geoacoustical results were ground-truthed with physical samples of sea floor sediment.