MAINE SALT POOLS: STRATIGRAPHIC DESCRIPTION, ECOPHYSICAL CHARACTERIZATION, AND DISCUSSION OF THEIR ROLE IN ESTUARINE LANDSCAPE CHANGE

MAINESALT POOLS:  STRATIGRAPHIC DESCRIPTION, ECOPHYSICAL CHARACTERIZATION, AND DISCUSSION OF THEIR ROLE IN

ESTUARINE LANDSCAPE CHANGE

By Kristin R. Wilson

Thesis Advisor:  Dr. Joseph T. Kelley

A Lay Abstract of the Thesis Presented

in Partial Fulfillment of the Requirements for the

Degree of Doctor of Philosophy

(in Ecology and Environmental Sciences)

August, 2010

            Salt marshes are critical components of our coastal systems.  Salt pools, shallow, water-filled depressions, are common features found throughout north-temperate salt-marsh environments.  Despite this, little is known regarding their origin, stratigraphic signature, characterization, or potential role in driving surficial changes in salt-marsh systems.  This study combines approaches from geology, ecology, and spatial information sciences to characterize pools of six Maine salt marshes (from south to north:  Moody Marsh, Ogunquit; Webhannet Marsh, Wells; Maquoit Bay Marsh, Brunswick; Grand Marsh, Gouldsboro; Addison Marsh, Addison, and Lubec Spit Marsh, Lubec).  Overall, our study results indicate that marsh pools are highly dynamic, that this dynamism is recorded in the geologic record, and that total pool area within Maine marshes is increasing by a slight to moderate amount.  Finer-scale investigations of pool aquatic conditions reveal that this dynamism is seen at the pool scale in terms of variability in pool salinities, temperatures, and water levels and that groundwater flows may influence surficial pool morphologies.  This study demonstrates the dynamic nature of Maine’s salt-marsh and salt-pool environments, though it does not appear that Maine’s salt marshes are transitioning to open-water states at the rapid time scales observed for other regions.  Rather, Maine marshes appear to be in a state of dynamic equilibrium.