Abstract
Intertidal creeks (<5m width) weave through salt marshes,
delivering water, nutrients, and sediments into the marsh interior and
alter spatial heterogeneity in plant and animal distributions. Despite
their global prevalence, creek connectivity, and the mechanisms
controlling cross-marsh hydrodynamics, remain poorly resolved. In this
study, we measured flow and total suspended solids (TSS) transport in
three intertidal creeks within a confined drainage basin in a Georgia,
USA salt marsh. We discovered that the effective drag is 3 to 12 times
greater than bed drag, reaching levels similar to those observed in
coral reefs. Furthermore, the drag between tidal flood and ebb phases
differ, suggesting a non-symmetric drag. Analyses of along-channel
momentum reveal that the friction O(10E-3 - 10E-2 ) and pressure
gradient O(10E-3 - 10E-2) dominate creek momentum balance. Divergence in
tidal and TSS transport between adjacent creeks reveals opposing tidal
asymmetries within this confined basin. We suggest that these
differences may mediate the eco-geospatial evolution of salt marshes and
their response to sea level rise.