Temporal and Spatial Analysis of Water Quality and Landscape Characteristics for Albemarle Sound, North Carolina

Abstract

Albemarle Sound, a lagoonal estuarine system on the North Carolina coast, has experienced a large decline in recreational and commercial fisheries over the years and managers are concerned about water quality, including the impacts of nutrient enrichment, or eutrophication. In an effort to help the United States Geological Survey improve its water quality monitoring network, this report compiles and analyzes over 40 years of historic data for the sound using three approaches. Based on the current monitoring program and available historic data collected, five chemical and biological water quality parameters were chosen to characterize the water quality in Albemarle Sound: chlorophyll-a (Chl-a), dissolved oxygen (DO), turbidity, inorganic nitrogen (nitrate and nitrate) as N and phosphate-phosphorus as P. This project 1) statistically analyzes the relationships between water quality parameters within and among sub-sections of the Sound; 2) combines multiple sources of LULC data into sub-sections to better understand water quality drivers; 3) develops a GIS-based user interactive toolkit to identify the sensitive location(s). Statistical and geospatial analyses show: 1) Overall, water quality in Albemarle Sound is good over time. 2) Seasonal effects may influence parameter values in some parts of the sound. 3) In light of inorganic nitrogen and phosphate-phosphorus levels, we may pay more attention to the North and South sections, as these two sections were more vulnerable to nutrient problems in history. 4) There are major differences in landscape characteristics between sections, offering some explanation for differences in water quality, and 5) There are some signals in the average concentrations of the five water quality parameters from 2006-2013, indicating that terrestrial drivers such as CAFO animal density and percent cultivated area could be important for water quality in the Albemarle Sound. This report provides fundamental guidance that can be used to inform both management plans and future studies in Albemarle Sound