Intertidal Rockweed and Oysters in Great Bay, New Hampshire - Monitoring Dataset

InvestigatorsRay Grizzle, David Burdick, Krystin Ward, Gregg Moore, Lauren White, and Grant McKownOrganizationJackson Estuarine Laboratory, School of Marine Sciences & Ocean Engineering, University of New HampshireContactGrant McKown, [e-mail] or [e-mail] DescriptionRockweed macroalgae (Ascophyllum and Fucus sp.) was mapped through automated classification in Google Earth Engine using 2015 Leaf-off Imagery and 2012 - 2016 NAIP imagery. Thresholds were assigned to pre-selected remote sensing indices (Brown Algae Index, Water Index, Red - Blue Ratio, and Elevation). Preliminary classification of rockweed distribution was then refined through boat field surveys to remove erroneously classified salt marshes and overhanging canopy, which is inherent to the classification process. Accuracy assessments were carried out (n = 230 points) across the estuary and an overall accuracy of 90.5% was observed. Field survey sites (n = 25) were extracted from rockweed distribution and surveyed for eastern oyster and mussel use underneath rockweed canopy. Salinity metrics for each region of Great Bay were calculated from SWMP water quality datasondes between 2015 - 2023.Please Note - After a minor error on oyster density calculations were discovered in Februar 2026, corrections were made to rectify the miscalculations throughout the dataset and statistical models. The corrected dataset has replaced the original dataset. The authors humbly apologize for the misoversight.