Alysha B. Putnam Ally R. Jones Lucy A. D. Lockwood Michelle D. Staudinger 20250617 tabular digital data ScienceBase U.S. Geological Survey https://doi.org/10.5066/P14697CK This data set contains information on the occurrence and abundance of intertidal marine invertebrates and macro algae collected across five islands with 10 sites in the Boston Harbor in 2023. This data was collected using an intertidal biodiversity monitoring protocol developed specifically for the mixed coarse substrate habitat found on the inner islands of Boston Harbor, including Gallops, Georges, Lovells, Peddocks, and Thompson Island. Species were identified and total counts of mobile invertebrates and percent cover for macro algae and sessile invertebrates in randomly distributed 0.5 square meter quadrats. Data included in this release was used to determine community composition and diversity metrics across high biodiversity and erosional sites for the five islands. This data was collected in support of the "A Novel Monitoring Framework to Assess Intertidal Biodiversity in Mixed Coarse Substrate Habitats Across the Boston Harbor Islands" project. It was developed because the Boston Harbor currently lacks a centralized list of the occurrence, distribution, and abundance of intertidal marine species. 20230608 20230809 ground condition Complete None planned -71.0100 -70.8600 42.3600 42.2500 ISO 19115 Topic Category biota oceans None Mixed coarse substrate Macro algae Marine invertebrates USGS Thesaurus biodiversity climate change USGS Metadata Identifier USGS:66cf2dddd34e98e8a924b8ac None Boston Harbor Islands National and State Park Boston Harbor None. Please see 'Distribution Info' for details. These data are marked with a Creative Common CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Alysha B. Putnam Northeast Climate Adaptation Science Center mailing and physical

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West Springfield MA 01089 United States 413-784-5094 aputnam@umass.edu This work was funded by the U.S. Geological Survey Northeast Climate Adaptation Science Center. This data was in part collected by Anne Pierre, Kayleah Unglaub, Angel Checo Reynoso, Cody Pajic, Isabelle Freda, Zoe Fu Chen, Sydney Jones, Lucy A. D. Lockwood, Michelle Staudinger and Taryn Broughal. No formal attribute accuracy tests were conducted. Data were checked for duplication, omission, and logical consistency. All values fall within expected ranges. Data set is considered complete for the information presented, as described in the abstract. Data represents occurrences only within the five Boston Harbor Islands listed within the abstract. Dataset only includes invertebrates and algae found in the intertidal and does not include any other taxon (e.g. birds, fish, and mammals). Users are advised to read the rest of the metadata record carefully for additional details. We constructed this biodiversity dataset using an intertidal biodiversity monitoring protocol designed for mixed coarse substrate habitats. We selected five islands, with two sites per island categorized as either high biodiversity or erosional. At each field site, we established a 48 m wide sampling grid divided into nine quadrants arranged in a 3 x 3 layout, spanning high, mid, and low intertidal zones. A horizontal transect tape was placed along the upper shoreline (48 m), and vertical transect lines were established every 16 m, extending from the upper shoreline down to mean low water. The vertical distance varied across sites depending on shoreline characteristics. Quadrats (0.5 m2) were placed at pre-determined coordinates within each quadrant. Teams of two surveyed each quadrat, identifying all species present and recording abundance as counts for mobile invertebrates and percent cover for macroalgae and sessile invertebrates. 20240204 Alysha B. Putnam Northeast Climate Adaptation Science Center mailing and physical

18 glenview drive

West Springfield MA 01089 United States 413-784-5094 aputnam@umass.edu Intertidal_biodiversity_boston_harbor23.csv Comma Separated Value (CSV) file containing data. Producer Defined Date Date from when the data was collected in the field, represented in a YYYYMMDD format. Producer Defined 20230608 20230809 Island Name of the Boston Harbor Island where the observations were made. Producer Defined Islands and peninsulas of the Boston Harbor. Site Name of the sampling site on the island. Producer Defined Erosional Site identified by National Park Service that is both of cultural importance and has erosion occurring. Producer defined High Biodiversity Site identified by scientific expertise as having high number of species present. Producer defined ObsID A unique identifying value for quadrat observations. Producer Defined 1 358 QuadratNumber Quadrat identification number. Producer Defined A 0.5^2m frame used in field research to isolate a standard area in order to represent a larger habitat. Acts as individual numbered sample sites to assess distribution of algae and invertebrates. Tidalzone One of three tidal height zones determined by dividing the total vertical length of the field site into approximate thirds. Producer Defined High Upper third of the field site. Producer defined Mid Middle third of the field site. Producer defined Low Lower third of the field site. Producer defined Biozone One of five zones determined based on the dominance of a particular species of interest. Not all zones are present at every site. This is derived from the NPS Long Term Monitoring Protocol. Producer Defined NA No Data Producer defined Ascophyllum Zone in a rocky intertidal habitat mainly comprised of ascophyllum. Producer defined Fucus Zone in a rocky intertidal habitat mainly comprised of fucus. Producer defined None Zone in a rocky intertidal habitat that is not dominated by any algal or sessile invertebrate. Producer defined Red algae Zone in a rocky intertidal habitat mainly comprised of red algae. Producer defined Barnacle Zone in a rocky intertidal habitat mainly comprised of barnacle. Producer defined Mussels Zone in a rocky intertidal habitat mainly comprised of mussel. Producer defined Taxon The taxon that the recorded species resides in, grouped into either invertebrate or algal group. Producer Defined NA No Data Producer defined Algae Marine seaweed. Producer defined Invertebrate An animal lacking a backbone. Producer defined Phylum The phylum that the recorded species resides in. Producer Defined NA No Data Producer defined The field contains the taxonomic designation as listed in WoRMS for the species recorded. Class The class that the recorded species resides in. Producer Defined NA No Data Producer defined The field contains the taxonomic designation as listed in WoRMS for the species recorded. Order The order that the recorded species resides in. Producer Defined NA No Data Producer defined The field contains the taxonomic designation as listed in WoRMS for the species recorded. Family The family that the recorded species resides in. Producer Defined NA No Data Producer defined The field contains the taxonomic designation as listed in WoRMS for the species recorded. Genus The genus that the recorded species resides in. Producer Defined NA No Data Producer defined The field contains the taxonomic designation as listed in WoRMS for the species recorded. Species The scientific name of the recorded species. Producer Defined NA No Data Producer defined A Latin scientific name that consists of a genus, specific epithet, and/or subspecies or variety name. Appears as listed in WoRMS for the species recorded. Subspecies Subspecies name if known and identifiable. Producer Defined NA No Data Producer defined A Latin scientific name that consists of a genus, specific epithet, and subspecies. Appears as listed in WoRMS for the subspecies recorded. Status The origin status that the recorded species observed belongs to. Producer Defined NA No Data Producer defined Native Species that have been historically present in a region as determined by scientific evidence, such as paleobiogeography and molecular analysis. Producer defined NIS Species that are found outside of their native range, having been transported by human activities to an area where they have previously been absent. Producer defined Percent The percent value of sessile species observed in a quadrat. Producer Defined NA No Data Producer defined When observing and making an estimate of cover of sessile species, each grid square is further divided into approximate quarters. The total number of squares covered is then calculated as a percentage of the full 25 grid squares within the quadrat and is entered in decimal form. Species measured in percent cover include algae, barnacles, mussels, colonial invertebrates (bryozoans, tunicates). Count The count of number of individual species of mobile invertebrates observed in a quadrat. Producer Defined NA No Data Producer defined The number or count of mobile invertebrates observed in a quadrat. Species measured by number or count typically include arthropods, gastropods, or echinoderms. Substrate The type of substrate within the quadrat using a set of categories adapted from the Wentworth scale. Producer Defined Boulders Substrate within quadrat is comprised of >75% boulders. Producer defined Mixed coarse & fine Substrate within quadrat includes fine particles, no substrate type exceeds 75% cover, <50% boulders. Producer defined Gravel Substrate within quadrat is >75% granule and pebbles. Producer defined Mixed coarse Substrate within quadrat consists of sand and boulders, no substrate type exceeds 75% cover. Producer defined Cobble Substrate within quadrat is >75% cobble. Producer defined Shell Substrate within quadrat is >75% shell. Producer defined Sand Substrate within quadrat is >75% sand. Producer defined Mud Substrate within quadrat is >75% mud. Producer defined Notes Notes on the data observation that are not listed in the drop down options. Producer Defined NA No Data Producer defined Notes on the data observation such as changes to data while in field, such tide pool proximity, and other items not listed in the drop down. Name The initials of researchers. Producer Defined NA No Data Producer defined Initials of researchers who recorded the observations of species in the field. DataQAQC Notes on observations or changes made to the data. Producer Defined NA No Data Producer defined Additional notes on if any changes were made to the data during the data cleaning process, along with an initial of the researcher who made the change. GS ScienceBase U.S. Geological Survey mailing

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Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P14697CK None 20250617 CASC Data Management Team U.S. Geological Survey - CASC mailing and physical

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Reston VA 20192 United States NA casc-data@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998