2.2.2 Salinity
Because data collected through the NCDMF monitoring program may have preferential sampling bias, we sought to analyze additional salinity data collected from an unbiased monitoring program in order to understand how the NCDMF observations compared to an independent dataset. We accessed the North Carolina Division of Water Resources (NCDWR) Water Quality Portal (Water Quality Portal, 2021). The NCDWR dataset consists of 17 monitoring stations that had at least 10 years of salinity data between the years 1999 and 2021 and were within proximity to the NCDMF water quality sampling stations (Figure 2); stations with fewer than 10 years of data or in portions of the estuary that did not overlap with NCDMF stations (e.g., fresh headwaters) were not considered in the analysis. However, data from NCDWR sites in SGAs D and E were still considered despite being relatively distant from NCDMF monitoring locations as these were the only NCDWR sites present in SGAs D and E.