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The Albemarle Sound region was selected in 2012 as one of two demonstration sites in the Nation to test and improve the design of the National Water Quality Monitoring Council’s National Monitoring Network (NMN) for U.S. Coastal Waters and Tributaries. The goal of the NMN for U.S. Coastal Waters and Tributaries is to provide information about the health of our oceans, coastal ecosystems, and inland influences on coastal waters for improved resource management. The NMN is an integrated, multidisciplinary, and multi-organizational program using multiple sources of data and information to augment current monitoring programs. This report presents and summarizes selected waterquality and bed sediment-quality data collected as part of the demonstration project conducted in two phases. The first phase was an occurrence and distribution study to assess nutrients, metals, pesticides, cyanotoxins, and phytoplankton communities in the Albemarle Sound during the summer of 2012 at 34 sites in Albemarle Sound, nearby sounds, and various tributaries. The second phase consisted of monthly sampling over a year (March 2013 through February 2014) to assess seasonality in a more limited set of constituents including nutrients, cyanotoxins, and phytoplankton communities at a subset (eight) of the sites sampled in the first phase. During the summer of 2012, few constituent concentrations exceeded published waterquality thresholds; however, elevated levels of chlorophyll a and pH were observed in the northern embayments and in Currituck Sound. Chlorophyll a, and metals (copper, iron, and zinc) were detected above a water-quality threshold. The World Health Organization provisional guideline based on cyanobacterial density for high recreational risk was exceeded in approximately 50 percent of water samples collected during the summer of 2012. Cyanobacteria capable of producing toxins were present, but only low levels of cyanotoxins below human health benchmarks were detected. Finally, 12 metals in surficial bed sediments were detected at levels above a published sediment-quality threshold. These metals included chromium, mercury, copper, lead, arsenic, nickel, and cadmium. Sites with several metal concentrations above the respective thresholds had relatively high concentrations of organic carbon or fine sediment (silt plus clay), or both and were predominantly located in the western and northwestern parts of the Albemarle Sound. Results from the second phase were generally similar to those of the first in that relatively few constituents exceeded a water-quality threshold, both pH and chlorophyll a were detected above the respective water-quality thresholds, and many of these elevated concentrations occurred in the northern embayments and in Currituck Sound. In contrast to the results from phase one, the cyanotoxin, microcystin was detected at more than 10 times the water-quality threshold during a phytoplankton bloom on the Chowan River at Mount Gould, North Carolina in August of 2013. This was the only cyanotoxin concentration measured during the entire study that exceeded a respective water-quality threshold. The information presented in this report can be used to improve understanding of water-quality conditions in the Albemarle Sound, particularly when evaluating causal and response variables that are indicators of eutrophication. In particular, this information can be used by State agencies to help develop water-quality criteria for nutrients, and to understand factors like cyanotoxins that may affect fisheries and recreation in the Albemarle Sound region. Introduction The Albemarle Sound region was selected in 2012 as one of two demonstration sites in the Nation to test and improve the design of the National Water Quality Monitoring Council’s National Monitoring Network (NMN) for U.S. Coastal Waters and Tributaries. The goal of the NMN for U.S. Coastal Waters and Tributaries is to provide information about the health of our oceans, coastal ecosystems and inland influences on coastal waters for improved resource management. The NMN is an integrated, multidisciplinary, and multi-organizational program using multiple sources of data and information to augment current (2015) monitoring programs. 2 Water Quality and Bed Sediment Quality in the Albemarle Sound, North Carolina, 2012–14 The demonstration project began in February 2012, to document current and historic monitoring and research programs in the Albemarle Sound and identify monitoring gaps (Moorman and others, 2014). One of the identified data gaps was the need for increased monitoring of nutrients, metals, pesticides, and phytoplankton communities in the Albemarle Sound. As part of the demonstration project, the U.S. Geological Survey (USGS) collaborated with the North Carolina Department of Environment and Natural Resources (NCDENR) Division of Water Resources (DWR) to address this monitoring gap. This information can be used by DWR and its partners to help develop nutrient criteria for the Albemarle Sound region under the Clean Water Act of 1972. Background The Albemarle Sound is part of the Albemarle-Pamlico estuarine system, the second largest estuary in the lower 48 States of the United States (Giordano and Holloman, 2001). Albemarle Sound and its tributaries form a shallow, low salinity lagoonal estuary (Jia and Li, 2012) oriented east to west in northeastern North Carolina and southeastern Virginia (fig. 1). The Albemarle Sound covers a surface area of 2,330 square kilometers surrounded by more than 800 kilo meters (km) of shoreline and has a drainage area of 47,552 square kilometers (Steel, 1991). For the purpose of this report, the Albemarle Sound study area has been defined as a region including the Pasquotank, Lower Roanoke, and Chowan River Basins that includes the waters and adjacent wetlands draining into and out of the Albemarle Sound. In addition, lower portions of the Meherrin, Nottoway, and Blackwater River Basins are included because most of the Chowan River is tidally influenced. The precise boundary of the study area was based on the boundaries of the hydrologic units identified by their USGS 12-digit hydrologic unit codes. The Albemarle Sound study area lies completely within the Coastal Plain of North Carolina and Virginia and comprises an extensive complex of creeks, rivers, wetlands, and open sound. In their calculations of the annual water budget for the Albemarle Sound, Giese and others (1979) computed an average influx of 17,000 cubic feet per second (ft3/s) of water entering the Albemarle Sound. Although runoff and precipitation vary seasonally, annual mean flow estimates based on data from USGS streamgages indicated the Roanoke and Chowan Rivers contribute 8,900 and 4,600 ft3/s, respectively. Several smaller rivers and tidal creeks drain coastal-area swamps, including the Perquimans, Little, Pasquotank, and North Rivers in the northern part of the Albemarle Sound and the Scuppernong and Alligator Rivers in the southern part of the sound, but they accounted for only a quarter (approximately 2,900 ft3/s) of the total freshwater inflow to the sound. An additional 3,400 ft3/s of water was estimated to be contributed by direct precipitation on the water surface. Although the Giese and others (1979) study is nearly 30 years old, it is still the most current and used streamflow data that dated back to the 1920s for some sites. The approximate residence time of water in the sound is 45 days because there is no direct connection to, and little exchange with, the Atlantic Ocean. Barrier islands form the eastern boundary of the study area and isolate the sound from the ocean (Giese and others, 1979). Because there is little tidal exchange between the Albemarle Sound and Oregon Inlet, wind-driven tides are the primary driver of water movement in the sound, with southwesterly winds predominating except during major storm events (Jia and Li, 2012). The climate for the region is relatively mild, with mean winter temperatures ranging between 6 and 8 degrees Celsius and mean summer temperatures commonly exceeding 32 degrees Celsius. Mean annual precipitation in the study area ranges from 111 to 137 centimeters per year (Parameterelevation Regressions on Independent Slopes Model [PRISM], 2012). There is little seasonal variation in rainfall, but the amount can vary substantially between dry years, when total precipitation can be less than 89 centimeters, and wet years, when total precipitation can exceed 200 centimeters (Carpenter and Dubbs, 2012). The Albemarle Sound region has been recognized as a location most likely to be affected by climate change because of its geography (Ezer and others, 2013). The Albemarle Sound study area is predominantly rural, with a population of approximately 520,000 people and few urban areas, except for tourism-related development near the coast along the barrier islands and City of Virginia Beach suburbs (U.S. Census Bureau, 2011). According to the 2006 National Land Cover Database, 28.1 percent of the land in the study area was wetland; 24.1 percent was cropland; 15.1 percent was forested; 21.2 percent was open water; 6.4 percent was barren, shrub/scrub, or grassland; and 5.2 percent was classified as developed (Fry and others, 2011). Before settlement, much of the land consisted of peat wetlands known as pocosins. In the past century, most of the pocosins have been ditched and drained to allow agricultural and silvicultural activities (Copeland and others, 1983). In general, there has been a decline in the extent of forests and wetlands in the area during the past 20 years (Carpenter and Dubbs, 2012, p. 45–53). Accelerated eutrophication from increased nutrient inputs associated with changing land use is of concern. Harmful algal blooms can disrupt aquatic ecosystems and trigger fish kills from bloom decomposition and food web changes (Burkholder, 1998; Anderson and others, 2002). Cyanobacteria and cylindrospermopsin, a cya

Water quality and bed sediment quality in the Albemarle Sound, North Carolina, 2012–14