Kenner, M.C. Leischner, T.C. Collins, K.F. Miles, A.K. Myers, S.L. Randell, Z. Sanchez, K. Story, A.A. Tomoleoni, J.A. 2024 spreadsheet https://doi.org/10.5066/P13TBWNZ Ryan E. Langendorf James A. Estes Jane C. Watson Michael C. Kenner Brian B. Hatfield M. Tim Tinker Ellen Waddle Megan L. DeMarche Daniel F. Doak 20250303 Publication Proceedings of the National Academy of Sciences (PNAS) Vol. 122, Issue 10 n/a Proceedings of the National Academy of Sciences https://doi.org/10.1073/pnas.2413360122 These data represent density per square meter of individuals of a suite of kelp and macroinvertebrate species on fixed 10-meter by 2-meter benthic transects on permanent subtidal monitoring sites around San Nicolas Island between 1980 and 2019. There are a total of nine sites, each of which has five 20 square meter band transects. Six of the sites were first sampled in 1980, one additional was added in 1987, and the other two were added in 2014. The sites have usually been monitored twice per year, most often in October and April. The target species list is as follows: Strongylocentrotus franciscanus (also known as Mesocentrotus franciscanus) Strongylocentrotus purpuratus Apostichopus parvimensis Pycnopodia helianthoides Patiria miniata Pisaster giganteus Astrometis sertulifera Dermasterias imbricata Haliotis corrugata Haliotis rufescens Megathura crenulata Megastraea undosa Cystoseira osmundacea (also known as Stephanocystis osmundacea) Eisenia arborea Laminaria spp. Macrocystis pyrifera <1 m tall Macrocystis pyrifera >1 m tall Pterygophora californica Young Laminariales (species uncertain) In fall 2014, the following additional organisms were added to the target list: Lytechinus anamesus Kelletia kelletii Crassadoma gigantea Aplysia californica Tealia lofotensis (also known as Urticina eques) Tethya aurantia (also known as Tethya aurantium) Sargassum horneri These data were collected as part of a long-term kelp forest ecosystem monitoring project. They provide the user an indication of the composition, persistence, and changes in kelp and macroinvertebrate populations in the near-shore rocky community around San Nicolas Island, CA. 19800826 20191005 ground condition Planned Irregular Naval Base Ventura County, San Nicolas Island, California -119.580100 -119.444100 33.273900 33.216000 ISO 19115 Topic Category biota Marine Realms Information Bank (MRIB) keywords kelp forest brown algae and kelp sea urchins and sand dollars Coastal and Marine Ecological Classification Standard Attached Sea Urchins Benthic Macroalgae USGS Thesaurus benthic ecosystems USGS Metadata Identifier USGS:670993ded34e969edc5a2d42 Common geographic areas San Nicolas Island Southern California Coastal California Northeast Pacific Pacific Integrated Taxonomic Information System (ITIS) and [World Register of Marine Species (WoRMS)] Strongylocentrotus franciscanus [Mesocentrotus franciscanus] Strongylocentrotus purpuratus Lytechinus anamesus Apostichopus parvimensis Pycnopodia helianthoides Patiria miniata Pisaster giganteus Astrometis sertulifera Dermasterias imbricata Aplysia californica Haliotis corrugata Haliotis rufescens Megathura crenulata Megastraea undosa Kelletia kelletii Crassadoma gigantea Tealia lofotensis [Urticina eques] Tethya aurantia [Tethya californiana or Tethya aurantium] Cystoseira osmundacea [Stephanocystis osmundacea] Sargassum horneri Eisenia arborea Pterygophora californica Macrocystis pyrifera Laminariales Laminaria U.S. Geological Survey 2013 Online Database https://doi.org/10.5066/F7KH0KBK www.itis.gov WoRMS Editorial Board Unknown Online Database https://doi.org/10.14284/170 https://www.marinespecies.org expert identifier Domain Eukaryota Kingdom Animalia animals Subkingdom Bilateria Infrakingdom Deuterostomia Phylum Echinodermata echinoderms Subphylum Echinozoa Class Echinoidea heart urchins sand dollars sea urchins urchins Subclass Euechinoidea Superorder Echinacea Order Echinoida Family Strongylocentrotidae Genus Strongylocentrotus Species Strongylocentrotus franciscanus TSN: 157971 Species Strongylocentrotus purpuratus TSN: 157975 Order Temnopleuroida Family Toxopneustidae Genus Lytechinus Species Lytechinus anamesus TSN: 157929 Class Holothuroidea sea cucumbers Order Synallactida Family Stichopodidae Genus Apostichopus Species Apostichopus parvimensis TSN: 1078867 Subphylum Asterozoa Class Asteroidea sea stars starfishes starfish Superorder Forcipulatacea Order Forcipulatida Family Pycnopodiidae Genus Pycnopodia Sunflower Star Species Pycnopodia helianthoides Sunflower Star TSN: 157274 Family Asteriidae Genus Pisaster Species Pisaster giganteus TSN: 157256 Genus Astrometis Species Astrometis sertulifera TSN: 157264 Superorder Valvatacea Order Valvatida Family Asterinidae cushion stars Genus Patiria Species Patiria miniata TSN: 157133 Family Asteropseidae Genus Dermasterias Leather Star Garlic Star Species Dermasterias imbricata Leather star TSN: 157139 Infrakingdom Protostomia Superphylum Lophozoa Phylum Mollusca molluscs mollusks Class Gastropoda gastropods slugs snails Subclass Opisthobranchia Order Anaspidea Family Aplysiidae Genus Aplysia Species Aplysia californica California seahare TSN: 78032 Subclass Prosobranchia Order Archaeogastropoda Superfamily Pleurotomarioidea Family Haliotidae abalone Genus Haliotis abalone Species Haliotis corrugata pink abalone TSN: 69499 Species Haliotis rufescens red abalone TSN: 69497 Superfamily Fissurelloidea Family Fissurellidae Genus Megathura Species Megathura crenulata giant keyhole limpet TSN: 69627 Family Turbinidae Genus Megastraea Species Megastraea undosa wavy turban TSN: 567871 Order Neogastropoda Family Buccinidae Genus Kelletia Species Kelletia kelletii TSN: 73862 Class Bivalvia bivalves clams Subclass Pteriomorphia Order Ostreoida Family Pectinidae Genus Crassadoma Species Crassadoma gigantea giant rock-scallop TSN: 567420 Subkingdom Radiata Phylum Cnidaria cnidarians coelenterates Subphylum Anthozoa Class Anthozoa Subclass Hexacorallia Order Actiniaria anemones sea anemones Suborder Nyantheae Infraorder Thenaria Family Actiniidae Genus Tealia Species Tealia lofotensis TSN: 52572 Phylum Porifera sponges Class Demospongiae Order Hadromerida Family Tethyidae Genus Tethya Species Tethya aurantia TSN: 48574 Kingdom Chromista Subkingdom Chromista Division Phaeophyta brown algae Class Phaeophyceae Order Fucales Family Cystoseiraceae Genus Cystoseira Species Cystoseira osmundacea TSN: 11367 Family Sargassaceae Genus Sargassum TSN: 11389 Order Laminariales TSN: 11211 Family Alariaceae Genus Eisenia Species Eisenia arborea TSN: 11308 Genus Pterygophora Species Pterygophora californica TSN: 11303 Family Lessoniaceae Genus Macrocystis Species Macrocystis pyrifera TSN: 11274 Family Laminariaceae Genus Laminaria TSN: 11217 No access constraints. Please see 'Distribution Info' for details. No use constraints. Questions pertaining to appropriate use or assistance with understanding limitations or interpretation of the data are to be directed to the individuals/organization listed in the Point of Contact section. U.S. Geological Survey, Western Ecological Research Center Data Manager mailing address

3020 State University Drive, Modoc Hall, suite 4004

Sacramento CA 95819 US 279-782-0904 gs-b-werc_data_management@usgs.gov Thanks to the following for foresight, organizational support and/or diving assistance: James Estes, Tim Tinker, Chris Harrold, James Bodkin, and many volunteer divers. Thanks to the US Navy for access to the island and funding from 2014 to present. Windows 10, Excel 365 SNI_Swath_Densities.csv 3,302 kb These data consist of density calculated from counts made by scuba divers in variable oceanic conditions and may contain errors in counts or identification. Efforts have been made to verify that the data table reflects the records made by the observers. Density calculations are based on a nominal defined search area of 20 square meters per swath and this area is an under estimation of the actual search area due to sea floor rugosity. These data have been checked for outlying or nonsensical values to the extent possible. These data represent densities of target organisms at fixed sites only. The list of species and the number of sites was expanded slightly in fall 2014. The absence of the additional species in earlier data does not imply their actual absence in the field. The data do not represent all the species and densities found in the region. The swath/band transect method was used to determine densities of kelps and benthic macroinvertebrates. Five permanent 10-m x 2-m swaths, which run perpendicular to the main 50-m transect, were sampled by divers at each site. Although nominally 20 square meters, the actual substrate sampled per swath is more, because of reefs, undercuts, boulders and other benthic features. First, researchers attached a meter tape at a fixed point on the main transect and swam it out to an eyebolt embedded in the sea floor approximately 10 m away. On each swath the divers, using meter sticks as guides, then counted and recorded the target organisms that occurred within 1 m on either side of the tape. Below is the list of target organisms: Strongylocentrotus franciscanus [Mesocentrotus franciscanus] Strongylocentrotus purpuratus Apostichopus parvimensis Pycnopodia helianthoides Patiria miniata Pisaster giganteus Astrometis sertulifera Dermasterias imbricata Haliotis corrugata Haliotis rufescens Megathura crenulata Megastraea undosa Cystoseira osmundacea [Stephanocystis osmundacea] Eisenia arborea Laminaria spp. Macrocystis pyrifera <1 m tall Macrocystis pyrifera >1 m tall Pterygophora californica Young Laminariales (species uncertain) In fall 2014, the following additional organisms were added to the target list: Lytechinus anamesus [Lytechinus pictus] Kelletia kelletii Crassadoma gigantea Aplysia californica Tealia lofotensis [Urticina eques] Tethya aurantia [Tethya aurantium] Sargassum horneri Unknown The density of each species was calculated on each swath by dividing the species count by the nominal area of the swath (20 meters). Unknown 0.0197763038 0.0235272080 Decimal seconds WGS_1984 WGS 84 6378137.0 298.257223563 SNI_Swath_Densities.csv Density per square meter of target species counted on fixed band transects. Producer Defined Period Sequential sampling time period. Odd numbers are "fall" (August–December), even numbers are "spring" (February–June) beginning as "1" in fall 1980. Refer to SNI_SamplingPeriods.csv for list. Producer Defined Time periods ranging from 1 to 79. See SNI_Sampling_Periods.csv. PeriodDef Abbreviation of period definition Producer Defined F or S (fall or spring) and 2 digit year. See SNI_SamplingPeriods.csv. Site Numeric subtidal site name. More information in SNI_Subtidal_Sites.csv Producer Defined Site numbers ranging from 1 to 9. See SNI_Subtidal_Sites.csv. SiteName Verbal subtidal site name. More information in SNI_Subtidal_Sites.csv Producer Defined Nav Fac Site on the north side of the island - contiguous to Nav Fac North Producer defined West End Urchin Site on the southwest side of the island - contiguous with West End Kelp Producer defined West End Kelp Site on the southwest side of the island - contiguous with West End Urchin Producer defined West Dutch Harbor Site on the south side of the island - near East Dutch Harbor Producer defined East Dutch Harbor Site on the south side of the island - near West Dutch Harbor Producer defined Daytona Beach Site on the southeast side of the island - contiguous to South Daytona Beach Producer defined Sandy Cove Site on the west side of the island Producer defined Nav Fac North Site on north side of the island - installed contiguous to Nav Fac in 2014 Producer defined South Daytona Beach Site on southeast side of the island - installed contiguous to Daytona in 2014 Producer defined Swath Identities the permanent 20 m square band transect - approximate starting position along 50-m main transect and direction (Right or Left) Producer Defined 10R 10 meters along main transect and to the right Producer defined 22R 22 meters along main transect and to the right Producer defined 32L 32 meters along main transect and to the left Producer defined 39R 39 meters along main transect and to the right Producer defined 45R 45 meters along main transect and to the right Producer defined 10L 10 meters along main transect and to the left Producer defined 22L 22 meters along main transect and to the left Producer defined 32R 32 meters along main transect and to the right Producer defined 39L 39 meters along main transect and to the left Producer defined 45L 45 meters along main transect and to the left Producer defined SpeciesCode Code number for each species. See SNI_Swath_Species.csv for list. Producer Defined See SNI_Swath_Species.csv for list. Invertebrates are coded 24-158. Algae are coded 553-598. SpeciesName Name of species Producer Defined These are names as accepted by the Integrated Taxonomic Information System (itis.gov) in February 2024. Density_1m Density of the species per square meter on the swath calculated as the count divided by 20 square meters. Producer Defined 0 139.95 count per square meter 0.01 Date Date of sample Producer Defined Date as mm/dd/yyyy SNI_Sampling_Periods.csv Time periods when sampling was conducted, code and time period description. Producer Defined Period Sequential sampling time period. Producer Defined Time periods ranging from 1 to 79. Odd numbers are "fall" (August-December), even numbers are "spring" (February-June) beginning as "1" in fall 1980. PeriodName Season (Fall or Spring) and year. Producer Defined Season and year of sample that corresponds to Period PeriodNameBrief Abbreviation of period definition. Producer Defined F or S (fall or spring) and 2 digit year. SNI_Subtidal_Sites.csv Site names, locations, and when first sampled. Producer Defined Site Numeric subtidal site name. Producer Defined Numeric name of the 9 long-term subtidal sites around San Nicolas Island. SiteName Verbal subtidal site name. Producer Defined Nav Fac Site on the north side of the island - contiguous with North Nav Fac. Producer defined West End Urchin Site on the southwest side of the island - contiguous with West End Kelp. Producer defined West End Kelp Site on the southwest side of the island - contiguous with West End Urchin. Producer defined West Dutch Harbor Site on the south side of the island - near East Dutch Harbor. Producer defined East Dutch Harbor Site on the south side of the island - near West Dutch Harbor. Producer defined Daytona Beach Site on the southeast side of the island - contiguous with South Daytona Beach. Producer defined Sandy Cove Site on the west side of the island - has no paired site. Producer defined Nav Fac North Site on north side of the island - installed contiguous to Nav Fac in 2014. Producer defined South Daytona Beach Site on southeast side of the island - installed contiguous to Daytona in 2014. Producer defined SiteLat Approximate latitude (decimal degrees) near site center. WGS84 Producer Defined 33.216 33.2739 Degrees Latitude SiteLon Approximate longitude (decimal degrees) near site center. WGS84 Producer Defined -119.5801 -119.4441 Degrees Longitude SuperSite Numeric subtidal supersite name. The supersites are pairings of adjacent sites except for 15 which is only composed of one site. Producer Defined 11 composed of site 1 and site 8 Producer defined 12 composed of site 2 and site 3 Producer defined 13 composed of site 4 and site 5 Producer defined 14 composed of site 6 and site 9 Producer defined 15 composed of site 7 only Producer defined SuperSiteName Verbal subtidal supersite name. The supersites are pairings of adjacent sites except for Sandy Cove 50 which is only composed of one site. Producer Defined Nav Fac 100 Composed of Nav Fac and Nav Fac North. Producer defined West End Composed of West End Urchin and West End Kelp. Producer defined Dutch Harbor Composed of West Dutch Harbor and East Dutch Harbor. Producer defined Daytona 100 Composed of Daytona Beach and South Daytona Beach. Producer defined Sandy Cove 50 Consists of Sandy Cove site only. Producer defined Depth_m Approximate depth of site in meters Producer Defined 11.6 15.2 meters FirstSampled Season and year first sampled Producer Defined Season (F = Fall) followed by last two digits of year when site was first sampled. SNI_Swath_Species.csv Target species names, phylum, and category. Producer Defined SpeciesCode Code number for each organism or grouped organisms that were counted in the SNI_Swath_Densities.csv. Producer Defined Invertebrates are coded 24-158. Algae are coded 553-598. Lumped group or substrate Description of group if not a distinct genus or species Producer Defined << empty cell >> Does not apply Producer defined Young laminariales Juvenile kelps of the order Laminariales that were not identified to genus or species. Producer defined SpeciesName (current ITIS Feb 2024) Genus or genus and species name recognized as valid on ITIS.gov as of February, 2024. Producer Defined << empty cell >> None or not determined Producer defined Genus or genus and species name for organism. SpeciesNameWoRMS Feb 2024 Genus or genus and species name recognized as valid on www.marinespecies.org as of February, 2024. Producer Defined << empty cell >> None or not determined Producer defined Genus or genus and species name for organism. Phylum Phylum of the organism Producer Defined The taxonomic phylum that the organism belongs to. Category General category of organism. Producer Defined Motile Invert Invertebrate not adhered to the substrate Producer defined Cucumber Holothurian Producer defined Brown algae Phaeophyte that is not in the order Laminariales Producer defined Kelp Phaeophyte in the order Laminariales Producer defined Non-motile Invert Invertebrate adhered to the substrate Producer defined GS ScienceBase U.S. Geological Survey mailing address

Denver Federal Center, Building 810, Mail Stop 302

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 on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. CSV https://doi.org/10.5066/P13TBWNZ None 20250306 Michael C Kenner U.S. Geological Survey, SOUTHWEST REGION Wildlife Biologist mailing address

2885 Mission Street

Santa Cruz CA 95060 US 831-254-5184 831-459-2249 mkenner@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999