gov.noaa.nodc:0181898 eng utf8 dataset NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NOAA Contact Information Information for contacts at NCEI. information custodian 2025-11-21T14:19:26Z ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Seagrass canopy height, water depth, chlorophyll-a concentration and other plant and water quality indicators in Coastal Waters of Texas (NCEI Accession 0181898) 2018-12-19 publication 2025-03-19 revision 2018-12-03 creation International DOI Foundation (IDF) 10.25921/3gcr-4x94 NOAA National Centers for Environmental Information gov.noaa.nodc:0181898 NCEI Archive Management System 0181898 NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information publisher Timothy L. Whiteaker The University of Texas at Austin (UT Austin) twhit@ig.utexas.edu https://www.utexas.edu/ HTTPS The University of Texas at Austin (UT Austin) website Institution web page information resourceProvider UT Austin Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information resourceProvider Ken Dunton UT Austin Marine Science Institute ken.dunton@utexas.edu http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information principalInvestigator Kim Jackson UT Austin Marine Science Institute kim.jackson@utexas.edu http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information collaborator Sara Wilson UT Austin Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information collaborator Victoria Congdon UT Austin Marine Science Institute vmcongdon@utexas.edu http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information collaborator Wayne Hall UT Austin Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information collaborator Madison Becker UT Austin Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information collaborator Meiman Joe National Park Service (NPS) https://www.nps.gov HTTPS National Park Service (NPS) website Institution web page information collaborator Young, Lisa UT Austin Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information collaborator Kelly, Marty Texas State Parks and Wildlife Department (TPWD) http://www.tpwd.state.tx.us/spdest/ HTTP Texas State Parks and Wildlife Department (TPWD) website Institution web page information collaborator Kyle Capistrant-Fossa UT Austin Marine Science Institute kacf242@gmail.com http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information pointOfContact Timothy L. Whiteaker The University of Texas at Austin (UT Austin) whiteaker@utexas.edu https://www.utexas.edu/ HTTPS The University of Texas at Austin (UT Austin) website Institution web page information collaborator Meaghan Cuddy UT Austin Marine Science Institute meaghan.cuddy@utexas.edu http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information collaborator Patrick Bohannon Texas Commission on Environmental Quality collaborator Faye Grubbs Texas State Parks and Wildlife Department (TPWD) http://www.tpwd.state.tx.us/spdest/ HTTP Texas State Parks and Wildlife Department (TPWD) website Institution web page information collaborator Cindy Hobson Texas State Parks and Wildlife Department (TPWD) http://www.tpwd.state.tx.us/spdest/ HTTP Texas State Parks and Wildlife Department (TPWD) website Institution web page information collaborator Dunton, Ken University of Texas; University of Texas - Austin; Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Jackson, Kim University of Texas; University of Texas - Austin; Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Wilson, Sara University of Texas; University of Texas - Austin; Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Congdon, Victoria University of Texas; University of Texas - Austin; Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Capistrant-Fossa, Kyle University of Texas; University of Texas - Austin; Marine Science Institute kacf242@gmail.com http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Young, Lisa University of Texas; University of Texas - Austin; Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Cuddy, Meaghan University of Texas; University of Texas - Austin; Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Hall, Wayne University of Texas; University of Texas - Austin; Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Becker, Madison University of Texas; University of Texas - Austin; Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information author Meiman, Joe US DOI; National Park Service (NPS) https://www.nps.gov HTTPS National Park Service (NPS) website Institution web page information author Whiteaker, Timothy L. University of Texas - Austin twhit@ig.utexas.edu https://www.utexas.edu/ HTTPS The University of Texas at Austin (UT Austin) website Institution web page information author Bohannon, Patrick Texas Commission on Environmental Quality author Grubbs, Faye Texas Parks and Wildlife Department http://www.tpwd.state.tx.us/spdest/ HTTP Texas State Parks and Wildlife Department (TPWD) website Institution web page information author Hobson, Cindy Texas Parks and Wildlife Department http://www.tpwd.state.tx.us/spdest/ HTTP Texas State Parks and Wildlife Department (TPWD) website Institution web page information author Kelly, Marty Texas Parks and Wildlife Department http://www.tpwd.state.tx.us/spdest/ HTTP Texas State Parks and Wildlife Department (TPWD) website Institution web page information author National Park Service (NPS) https://www.nps.gov HTTPS National Park Service (NPS) website Institution web page information contributor The University of Texas at Austin (UT Austin) https://www.utexas.edu/ HTTPS The University of Texas at Austin (UT Austin) website Institution web page information contributor UT Austin Marine Science Institute http://www.utmsi.utexas.edu HTTP UT Austin Marine Science Institute website Institution web page information contributor tableDigital This dataset contains raw tier 2 sampling data starting from 2011 for Texas coastal waters related to seagrasses. Parameters measured include chlorophyll a concentration, water depth, dissolved oxygen, light attenuation, pH, salinity, Secchi depth, water temperature, total suspended solids, seagrass canopy height, and seagrass percent cover. Typical species represented within the data include Halodule wrightii, Thalassia testudinum, Syringodium filiforme, Halophila engelmannii, and Ruppia maritima. Sampling takes place at 567 permanent stations in Aransas and Redfish Bays, Corpus Christi Bay, and Upper and Lower Laguna Madre. Latitudes and longitudes for station locations are based on the NAD83 datum. There was limited sampling in 2016. This dataset also includes opportunistic sampling in Little Bay, San Antonio Bay, and Galveston Bay, as well as analytically measured tissue content of carbon, nitrogen, and phosphorus in Halodule wrightii and Thalassia testudinum plant samples collected from Aransas and Redfish Bays, Corpus Christi Bay, and the Laguna Madre along with stable isotope data from those samples. Data are provided in CSV format. These data were collected to support the study of a Texas Seagrass Monitoring Plan implemented using Tier 2 protocols, which are intended to provide rapid assessments of hydrography, seagrass areal coverage, species distributions and plant physiological conditions. These data can be used to evaluate spatial characteristics of seagrass habitat quality and identify regions exhibiting seagrass decline. Funding Agency: Mission-Aransas National Estuarine Research Reserve Funding Agency: Coastal Bend Bays & Estuaries Program Funding Agency: Texas General Land Office Funding Agency: Texas Coastal Management Program Funding Agency: National Oceanic and Atmospheric Administration Funding Agency: US DOI; National Park Service completed historicalArchive NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information pointOfContact asNeeded NCEI Accession 0181898 was revised and a new version of the archival package was published. Updates to existing archival packages may provide additional files or replace obsolete files. The latest version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession. Please see journal.txt in the /about directory for additional details on changes made. https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:0181898 Preview graphic PNG 0181898 NCEI ACCESSION NUMBER 2025-02-04 publication Carbon content of specimen CHLOROPHYLL A CONCENTRATION DELTA CARBON-13 DELTA NITROGEN-15 DISSOLVED OXYGEN LIGHT ATTENUATION Nitrogen content of specimen pH SALINITY Secchi depth suspended solids TOTAL PHOSPHORUS water depth WATER TEMPERATURE theme NODC DATA TYPES THESAURUS bottle laboratory analysis mass spectrometer multi-parameter water quality sensor PAR Sensor Secchi disk visual observation instrument NODC INSTRUMENT TYPES THESAURUS in situ laboratory analyses theme NODC OBSERVATION TYPES THESAURUS National Park Service The University of Texas at Austin UT Austin Marine Science Institute dataCentre NODC COLLECTING INSTITUTION NAMES THESAURUS UT Austin Marine Science Institute dataCentre NODC SUBMITTING INSTITUTION NAMES THESAURUS Coastal Waters of Gulf of America Coastal Waters of Texas Gulf of America Gulf of Mexico place NODC SEA AREA NAMES THESAURUS oceanography theme WMO_CategoryCode 2012-09-15 publication DOI/NPS > National Park Service, U.S. Department of the Interior dataCentre Global Change Master Directory (GCMD) Data Center Keywords 2025 revision 22 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > WATER DEPTH EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > CHLOROPHYLL EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITROGEN EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > OXYGEN EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PH EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > SUSPENDED SOLIDS EARTH SCIENCE > OCEANS > OCEAN OPTICS > ATTENUATION/TRANSMISSION EARTH SCIENCE > OCEANS > OCEAN OPTICS > SECCHI DEPTH EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE EARTH SCIENCE > OCEANS > SALINITY/DENSITY > SALINITY theme Global Change Master Directory (GCMD) Science Keywords 2025 revision 22 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Carbon to Nitrogen Ratio Carbon to Phosphorus Ratio Nitrogen to Phosphorus Ratio Sea Grasses - Canopy Height Sea Grasses - Percent Cover theme Provider Keywords MASS SPECTROMETERS > MASS SPECTROMETERS PAR SENSORS > Photosynthetically Active Radiation Sensors SECCHI DISKS > SECCHI DISKS VISUAL OBSERVATIONS > VISUAL OBSERVATIONS instrument Global Change Master Directory (GCMD) Instrument Keywords 2025 revision 22 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian PVC marked in 10 cm segments instrument Provider Instrument Types OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF AMERICA OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF MEXICO place Global Change Master Directory (GCMD) Location Keywords 2025 revision 22 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian 722X0X Send2NCEI Submission Package ID accessLevel: Public otherRestrictions Cite as: Dunton, Ken; Jackson, Kim; Wilson, Sara; Congdon, Victoria; Capistrant-Fossa, Kyle; Young, Lisa; Cuddy, Meaghan; Hall, Wayne; Becker, Madison; Meiman, Joe; Whiteaker, Timothy L.; Bohannon, Patrick; Grubbs, Faye; Hobson, Cindy; Kelly, Marty (2018). Seagrass canopy height, water depth, chlorophyll-a concentration and other plant and water quality indicators in Coastal Waters of Texas (NCEI Accession 0181898). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/3gcr-4x94. Accessed [date]. Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives. otherRestrictions Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose. Texas Statewide Seagrass Monitoring Program 2018 publication https://texasseagrass.org/ HTTPS https://texasseagrass.org/ Project website detailing the seagrass monitoring program for Texas Coastal Waters information crossReference program eng; USA utf8 environment oceans -97.508 -96.396 26 28.434 2011-07-15 2023-12-19 In this accession, NCEI has archived multiple versions of these data. The latest (and best) version of these data has the largest version number. NOAA National Centers for Environmental Information +1-301-713-3277 ncei.info@noaa.gov pointOfContact In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media. Contact NCEI for other distribution options and instructions. CSV ASCII TEXT 5.412 https://doi.org/10.25921/3gcr-4x94 HTTPS Web browser NCEI Dataset Landing Page Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/oas/181898 HTTPS Web browser Descriptive Information Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/download/181898 HTTPS Web browser HTTPS Navigate directly to the URL for data access and direct download. download ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0129/0181898/ FTP Any FTP client FTP These data are available through the File Transfer Protocol (FTP). FTP is no longer supported by most internet browsers. You may copy and paste the FTP link to the data into an FTP client (e.g., FileZilla or WinSCP). download dataset NCEI Accession 0181898 v1.1 was published. 2018-12-19T21:10:49Z NCEI Accession 0181898 v1.1 publication https://www.ncei.noaa.gov/archive/accession/0181898/1.1 HTTPS NCEI Accession 0181898 v1.1 published 2018-12-19T21:10:49Z download NCEI Accession 0181898 was revised and v2.2 was published. Updates were received for this dataset. These updates were copied into the data/0-data/ directory of this accession. These updates may provide additional files or replace obsolete files. This version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession. 2021-05-10T13:10:17Z NCEI Accession 0181898 v2.2 publication https://www.ncei.noaa.gov/archive/accession/0181898/2.2 HTTPS NCEI Accession 0181898 v2.2 published 2021-05-10T13:10:17Z download NCEI Accession 0181898 was revised and v3.3 was published. Updates were received for this dataset. These updates were copied into the data/0-data/ directory of this accession. These updates may provide additional files or replace obsolete files. This version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession. 2023-06-21T20:39:44Z NCEI Accession 0181898 v3.3 publication https://www.ncei.noaa.gov/archive/accession/0181898/3.3 HTTPS NCEI Accession 0181898 v3.3 published 2023-06-21T20:39:44Z download NCEI Accession 0181898 was revised and v4.4 was published. Updates were received for this dataset. These updates were copied into the data/0-data/ directory of this accession. These updates may provide additional files or replace obsolete files. This version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession. 2025-03-19T15:21:21Z NCEI Accession 0181898 v4.4 publication https://www.ncei.noaa.gov/archive/accession/0181898/4.4 HTTPS NCEI Accession 0181898 v4.4 published 2025-03-19T15:21:21Z download dataset Parameter or Variable: CHLOROPHYLL A CONCENTRATION (measured); Units: microgram/liter; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: Stations are approached slowly to ensure that the deceleration of the boat does not create a wake and resuspend sediments into the water column. All hydrographic and water column measurements are collected while the vessel is set to drift over the station to minimize interference from sediment plumes generated from physical disturbances of the bottom. Sonde deployment, water transparency and water sample collection must occur within 30 m of the station location. Measurements are made in the following order: (1) PAR, (2) visibility, (3) hydrography, (4) TSS, (5) depth, (6) percent coverage, (7) canopy height, and (8) blade samples for C:N:P ratios. While taking measurements, care is taken not to disturb the sediment or agitate seagrasses. The sonde is lowered so that the instrument probes are completely submerged.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: water depth (measured); Units: meter; Observation Category: in situ; Sampling Instrument: PVC marked in 10 cm segments; Sampling and Analyzing Method: Stations are approached slowly to ensure that the deceleration of the boat does not create a wake and resuspend sediments into the water column. All hydrographic and water column measurements are collected while the vessel is set to drift over the station to minimize interference from sediment plumes generated from physical disturbances of the bottom. Sonde deployment, water transparency and water sample collection must occur within 30 m of the station location. Measurements are made in the following order: (1) PAR, (2) visibility, (3) hydrography, (4) TSS, (5) depth, (6) percent coverage, (7) canopy height, and (8) blade samples for C:N:P ratios. While taking measurements, care is taken not to disturb the sediment or agitate seagrasses. Depth is measured using a PVC pipe marked in 10 cm segments. Care is taken to avoid allowing the PVC pole to sink into soft sediments.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: DISSOLVED OXYGEN (measured); Units: milligram/liter; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: Stations are approached slowly to ensure that the deceleration of the boat does not create a wake and resuspend sediments into the water column. All hydrographic and water column measurements are collected while the vessel is set to drift over the station to minimize interference from sediment plumes generated from physical disturbances of the bottom. Sonde deployment, water transparency and water sample collection must occur within 30 m of the station location. Measurements are made in the following order: (1) PAR, (2) visibility, (3) hydrography, (4) TSS, (5) depth, (6) percent coverage, (7) canopy height, and (8) blade samples for C:N:P ratios. While taking measurements, care is taken not to disturb the sediment or agitate seagrasses. The sonde is lowered so that the instrument probes are completely submerged.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: LIGHT ATTENUATION (measured); Units: kd/meter; Observation Category: in situ; Sampling Instrument: PAR Sensor; Sampling and Analyzing Method: Measurements of percent surface irradiance (% SI) and the diffuse light attenuation coefficient (k) are made from simultaneous measurements of surface (ambient) and underwater irradiance. Surface measurements of photosynthetically active radiation (PAR = ca. 400 to 700 nm wavelength) are collected using an LI-190SA quantum sensor that provides input to a LI-1000 datalogger (LI-COR Inc., Lincoln, Nebraska, USA). Underwater measurements are made using a LI-192SA or LI-193SA spherical quantum sensor. Measurements of % SI and k are based on three or more replicate determinations of instantaneous PAR collected by the surface and underwater sensors and recorded by the LI-1000 datalogger. Care is taken to reduce extraneous sources of reflected light (from boats or clothing). Percent surface irradiance available at the seagrass canopy is calculated as follows: % SI = (Iz/I0) x 100 where Iz and I0 are irradiance (μmol photons m-2sec-1) at depth z (meters) and at the surface, respectively. Light attenuation is calculated using the transformed Beer-Lambert equation: kd = -[ln(Iz/I0)]/z where k is the attenuation coefficient (m-1) and Iz and I0 are irradiance (μmol photons m-2 sec-1) at depth z (meters) and at the surface, respectively.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: pH (measured); Units: pH; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: Stations are approached slowly to ensure that the deceleration of the boat does not create a wake and resuspend sediments into the water column. All hydrographic and water column measurements are collected while the vessel is set to drift over the station to minimize interference from sediment plumes generated from physical disturbances of the bottom. Sonde deployment, water transparency and water sample collection must occur within 30 m of the station location. Measurements are made in the following order: (1) PAR, (2) visibility, (3) hydrography, (4) TSS, (5) depth, (6) percent coverage, (7) canopy height, and (8) blade samples for C:N:P ratios. While taking measurements, care is taken not to disturb the sediment or agitate seagrasses. The sonde is lowered so that the instrument probes are completely submerged.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: SEA GRASSES - PERCENT COVER (measured); Units: percent; Observation Category: in situ; Sampling Instrument: visual observation; Sampling and Analyzing Method: Species composition and areal coverage were obtained from four replicate quadrat samples per station at each of the four cardinal locations from the vessel. Percent cover of areal biomass was estimated by direct observation, looking down at the seagrass canopy through the water using a 0.25 m2 quadrat framer subdivided into 100 cells.; Data Quality Method: Data are checked against reasonable value ranges (0 to 100). A value of 9999 indicates no data available. Parameter or Variable: SALINITY (measured); Units: ppt; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: Stations are approached slowly to ensure that the deceleration of the boat does not create a wake and resuspend sediments into the water column. All hydrographic and water column measurements are collected while the vessel is set to drift over the station to minimize interference from sediment plumes generated from physical disturbances of the bottom. Sonde deployment, water transparency and water sample collection must occur within 30 m of the station location. Measurements are made in the following order: (1) PAR, (2) visibility, (3) hydrography, (4) TSS, (5) depth, (6) percent coverage, (7) canopy height, and (8) blade samples for C:N:P ratios. While taking measurements, care is taken not to disturb the sediment or agitate seagrasses. The sonde is lowered so that the instrument probes are completely submerged.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: SEA GRASSES - CANOPY HEIGHT (measured); Units: centimeter; Observation Category: in situ; Sampling Instrument: visual observation; Sampling and Analyzing Method: The four corners of the boat (port-stern, port-bow, starboard-bow, and starboard-stern) are used as seagrass sample locations. Measurements are taken approximately 2-4 meters from the boat by tossing a 0.25 m2 quadrat into the water and using a meter stick. Within each quadrat, five canopy height measurements are made for seagrass species present.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: SECCHI DEPTH (measured); Units: meter; Observation Category: in situ; Sampling Instrument: secchi disk; Sampling and Analyzing Method: Stations are approached slowly to ensure that the deceleration of the boat does not create a wake and resuspend sediments into the water column. All hydrographic and water column measurements are collected while the vessel is set to drift over the station to minimize interference from sediment plumes generated from physical disturbances of the bottom. Sonde deployment, water transparency and water sample collection must occur within 30 m of the station location. Measurements are made in the following order: (1) PAR, (2) visibility, (3) hydrography, (4) TSS, (5) depth, (6) percent coverage, (7) canopy height, and (8) blade samples for C:N:P ratios. While taking measurements, care is taken not to disturb the sediment or agitate seagrasses. When using a secchi disk for visibility measurements, sunglasses are removed and care is taken to prevent the vessel from shading the disk.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: WATER TEMPERATURE (measured); Units: degrees Celsius; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: Stations are approached slowly to ensure that the deceleration of the boat does not create a wake and resuspend sediments into the water column. All hydrographic and water column measurements are collected while the vessel is set to drift over the station to minimize interference from sediment plumes generated from physical disturbances of the bottom. Sonde deployment, water transparency and water sample collection must occur within 30 m of the station location. Measurements are made in the following order: (1) PAR, (2) visibility, (3) hydrography, (4) TSS, (5) depth, (6) percent coverage, (7) canopy height, and (8) blade samples for C:N:P ratios. While taking measurements, care is taken not to disturb the sediment or agitate seagrasses. The sonde is lowered so that the instrument probes are completely submerged.; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: suspended solids (measured); Units: milligram/liter; Observation Category: in situ; Sampling Instrument: bottle; Sampling and Analyzing Method: Replicate water samples were obtained at each station for determination of Total Suspended Solid (TSS) concentration. Bottles and lids are rinsed three times with sample water before collecting the sample. Gloves are worn if the collector is wearing sunscreen to prevent contamination of sample. The TSS method is adapted from EPA Method 160.2. Summary of Method: A well-mixed sample is filtered through a glass fiber filter, and the residue retained on the filter is dried to constant weight at 103-105°C. Sample Handling and Preservation Non-representative particulates such as leaves, sticks, fish, and lumps of fecal matter should be excluded from the sample if it is determined that their inclusion is not desired in the final result. Preservation of the sample is not practical; analysis should begin as soon as possible. Refrigeration or icing to 4°C, to minimize microbiological decomposition of solids, is recommended. Interferences: Filtration apparatus, filter material, pre-washing, post-washing, and drying temperature are specified because these variables have been shown to affect the results. Samples high in Filterable Residue (dissolved solids), such as saline waters, brines and some wastes, may be subject to a positive interference. Care must be taken in selecting the filtering apparatus so that washing of the filter and any dissolved solids in the filter minimizes this potential interference. Laboratory Procedures: 1) Dry new filters at 60°C in oven prior to use. 2) Weigh filter immediately before use. After weighing, handle the filter or crucible/filter with forceps or tongs only. 3) Place the glass fiber filter (i.e. Glass fiber filter discs, without organic binder, such as Millipore AP-40, Reeves Angel 934-AH, Gelman type A/E, or equivalent; Our lab uses 47 mm GF/F 0.7 micron retention) on the membrane filter apparatus. NOTE: Because of the physical nature of glass fiber filters, the absolute pore size cannot be controlled or measured. Terms such as “pore size”, “collection efficiencies” and “effective retention” are used to define this property in glass fiber filters. 4) For a 47 mm diameter filter, filter 100 mL of sample. If weight of captured residue is less than 1.0 mg, the sample volume must be increased to provide at least 1.0 mg of residue. If other filter diameters are used, start with a sample volume equal to 7 mL/cm of filter area and collect at least a weight of residue proportional to the 1.0 mg state above. NOTE: If filtering clear pristine water, start with 1 L. If filtering turbid water start with 100 mL. NOTE: If during filtration of this initial volume the filtration rate drops rapidly, or if filtration time exceeds 5 to 10 minutes, the following scheme is recommended: Use an unweighed glass fiber filter affixed in the filter assembly. Add a known volume of sample to the filter funnel and record the time elapsed after selected volumes have passed through the filter. Twenty-five mL increments for timing are suggested. Continue to record the time and volume increments until filtration rate drops rapidly. Add additional sample if the filter funnel volume is inadequate to reach a reduced rate. Plot the observed time versus volume filtered. Select the proper filtration volume as that just short of the time a significant change in filtration rate occurred. 5) Assemble the filtering apparatus and begin suction. 6) Shake the sample vigorously and quantitatively transfer the predetermined sample volume selected to the filter using a graduated cylinder. Pour into funnel. 7) Remove all traces of water by continuing to apply vacuum after sample has passed through. 8) With suction on, wash the graduated cylinder, filter, non-filterable residue and filter funnel wall with three portions of distilled water allowing complete drainage between washing. Remove all traces of water by continuing to apply vacuum after water has passed through. NOTE: Total volume of distilled rinse water used should equal no less than 50 mLs following complete filtration of sample volume. 9) Carefully remove the filter from the filter support. 10) Dry at least one hour at 103-105°C. Overnight drying ensures accurate filter weight. 11) Cool in a desiccator and weigh. 12) Repeat the drying cycle until a constant weight is obtained (weight loss is less than 0.5 mg). Calculations: TSS (mg/L) is calculated as follows: 1000 x (A-B) x (1000/C) = TSS where A = weight of filter (or filter and crucible) + residue (mg), B = weight of filter (or filter and crucible) (mg), and C = amount of sample filtered (mL).; Data Quality Method: Data are checked against reasonable value ranges. A value of 9999 indicates no data available. Parameter or Variable: Carbon content of specimen (calculated); Units: percent; Observation Category: laboratory analysis; Sampling Instrument: mass spectrometer; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N).; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. Blank values indicate the analysis was not run. Parameter or Variable: Nitrogen content of specimen (measured); Units: percent; Observation Category: laboratory analysis; Sampling Instrument: mass spectrometer; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N).; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. Blank values indicate the analysis was not run. Parameter or Variable: TOTAL PHOSPHORUS (calculated); Units: percent; Observation Category: laboratory analysis; Sampling Instrument: laboratory analysis; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue phosphorous content is determined following procedures described in [Chapman, H.D. and Pratt, P.F. 1961. Methods of Analysis for Soils, Plants and Water. Univ. California, Berkeley, CA, USA].; Data Quality Method: P analysis is run against a prepared standard curve approximately every 20 samples to ensure the spec is properly calibrated and reading correctly. If a value is extremely abnormal (for example, an order of magnitude higher or lower than what would be expected, clearly indicating some sort of contamination) it is excluded from the dataset. A value of -9991 indicates not enough phosphorus sample to run. Blank values indicate the analysis was not run. Parameter or Variable: Carbon content of specimen (measured); Units: micromole/milligram; Observation Category: laboratory analysis; Sampling Instrument: mass spectrometer; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N).; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. Blank values indicate the analysis was not run. Parameter or Variable: Nitrogen content of specimen (measured); Units: micromole/milligram; Observation Category: laboratory analysis; Sampling Instrument: mass spectrometer; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N).; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. Blank values indicate the analysis was not run. Parameter or Variable: TOTAL PHOSPHORUS (calculated); Units: micromole/milligram; Observation Category: laboratory analysis; Sampling Instrument: laboratory analysis; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue phosphorous content is determined following procedures described in [Chapman, H.D. and Pratt, P.F. 1961. Methods of Analysis for Soils, Plants and Water. Univ. California, Berkeley, CA, USA].; Data Quality Method: P analysis is run against a prepared standard curve approximately every 20 samples to ensure the spec is properly calibrated and reading correctly. If a value is extremely abnormal (for example, an order of magnitude higher or lower than what would be expected, clearly indicating some sort of contamination) it is excluded from the dataset. A value of -9991 indicates not enough phosphorus sample to run. Blank values indicate the analysis was not run. Parameter or Variable: DELTA CARBON-13 (measured); Units: per mille; Observation Category: laboratory analysis; Sampling Instrument: mass spectrometer; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N).; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. Blank values indicate the analysis was not run. Parameter or Variable: DELTA NITROGEN-15 (measured); Units: per mille; Observation Category: laboratory analysis; Sampling Instrument: mass spectrometer; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N).; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. Blank values indicate the analysis was not run. Parameter or Variable: Carbon to Nitrogen Ratio (calculated); Units: dimensionless; Observation Category: laboratory analysis; Sampling Instrument: laboratory analysis; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N).; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. Blank values indicate the analysis was not run. Parameter or Variable: Carbon to Phosphorus Ratio (calculated); Units: dimensionless; Observation Category: laboratory analysis; Sampling Instrument: laboratory analysis; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N). Tissue phosphorous content is determined following procedures described in [Chapman, H.D. and Pratt, P.F. 1961. Methods of Analysis for Soils, Plants and Water. Univ. California, Berkeley, CA, USA].; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. P analysis is run against a prepared standard curve approximately every 20 samples to ensure the spec is properly calibrated and reading correctly. If a value is extremely abnormal (for example, an order of magnitude higher or lower than what would be expected, clearly indicating some sort of contamination) it is excluded from the dataset. A value of -9991 indicates not enough phosphorus sample to run. Blank values indicate the analysis was not run. Parameter or Variable: Nitrogen to Phosphorus Ratio (calculated); Units: dimensionless; Observation Category: laboratory analysis; Sampling Instrument: laboratory analysis; Sampling and Analyzing Method: Collect samples of Thalassia and Halodule blades by manually snapping the seagrass shoot from the rhizome and keeping the sheath intact. Rinse sediment from tissue samples in the field. Be careful not to contaminate samples with sunscreen, lotion, etc. Roll the seagrass blades (minimum of 6 for Thalassia and 15 for Halodule) and place in a labeled Whirl-pak bag, removing all air, sealing, and placing on ice. In the lab, newly formed leaves (the youngest leaf in a shoot bundle) are gently scraped and rinsed in tap water to remove algal and faunal epiphytes. The rinsed tissue samples are then dried to a constant weight at 60°C and homogenized by grinding to a fine powder using a mortar and pestle. Tissue C:N Content, del-C13 and del-N15 tissue samples are analyzed for carbon and nitrogen concentrations and isotopic values using either a PDZ Europa ANCA-GSL elemental analyzer coupled to a PDZ Europa 20-20 isotope ratio mass spectrometer (UC-Davis; precision 0.2 per mille for 13C and 0.3 per mille for 15N), or a Carlo Erba 2500 elemental analyzer coupled to a Finnigan MAT DELTAplus isotope ratio mass spectrometer 23 (UTMSI; precision 0.3 per mille for both 13C and 15N). Tissue phosphorous content is determined following procedures described in [Chapman, H.D. and Pratt, P.F. 1961. Methods of Analysis for Soils, Plants and Water. Univ. California, Berkeley, CA, USA].; Data Quality Method: The EA-IRMS (all C and N parameters) is calibrated and run against known reference standards from the National Institute of Standards and Technology (NIST) to ensure that machine is running properly. Our CORE lab technician also performs regular independent checks and calibrations. This is done every every 10 samples, along with a size series at the set of samples. P analysis is run against a prepared standard curve approximately every 20 samples to ensure the spec is properly calibrated and reading correctly. If a value is extremely abnormal (for example, an order of magnitude higher or lower than what would be expected, clearly indicating some sort of contamination) it is excluded from the dataset. A value of -9991 indicates not enough phosphorus sample to run. Blank values indicate the analysis was not run. Parameter or Variable: CHLOROPHYLL A CONCENTRATION (measured); Units: microgram/liter; Observation Category: laboratory analysis; Sampling Instrument: bottle; Sampling and Analyzing Method: Analyzed following EPA 445.0*; Chlorophyll a - fluorometic method, with a modification contained in TCEQ SOP - HLAB 158; Data Quality Method: TCEQ SOP - HLAB 158 asNeeded Metadata are developed, maintained and distributed by NCEI. Updates are performed as needed to maintain currentness. NOAA National Centers for Environmental Information custodian bottle bottle any type of water bottle sampling device Generic name for water collection device; usually used to determine temperature, salinity and provide water aliquots for measurement of a wide range of parameters; often referred to by a specific type of water sampling bottle, such as a Nansen or Niskin bottle. laboratory analysis laboratory analysis use as an observation type mass spectrometer mass spectrometer Instrument that measure the massess and relative concentrations of atoms and molecules multi-parameter water quality sensor multi-parameter water quality sensor used to measure temperature, salinity, dissolved oxygen, and other parameters Instrument used to measure temperature, salinity, dissolved oxygen, and other parameters, often used to measure water quality parameters. Can be a hand-held instrument or a sonde for unattended monitoring. Often used in coastal water monitoring stations. YSI is the preeminent brand (as of 2024). PAR Sensor PAR Sensor Photosynthetically Active Radiation Sensor The PAR sensor measures global solar radiation from 400 to 700 nm, which approximates the spectral band active in photosynthesis. The response of the instrument falls sharply to zero on either side of this band, and between 400 and 670 nm it increases monotonically from about 50% to 100%. There is no protective glass dome over the receiving surface. Irradiance from the sun passes through a small white visible bandpass filter/diffuser in the shape of a horizontal disk at the top of the instrument. Within the instrument radiation is directed through a series of colored glass filters and onto a silicon photodiode detector. The factory-supplied calibration converts the signal from the detector to a flux of photons in micro-mole (of photons) s-1 m-2. (One micro-mole equals 6.022 E17 photons.) For the solar spectrum, these units may be converted to watts per square meter by dividing by 4.6. (http://www.srrb.noaa.gov/instrument/par.htm) Secchi disk Secchi disk The Secchi disk (or Secchi disc), as created in 1865 by Angelo Secchi, is a plain white, circular disk 30 cm (12 in) in diameter used to measure water transparency or turbidity in bodies of water. The disc is mounted on a pole or line, and lowered slowly down in the water. The depth at which the disk is no longer visible is taken as a measure of the transparency of the water. This measure is known as the Secchi depth and is related to water turbidity. [Wikipedia, 2021-09-02] visual observation visual observation not an instrument - maybe an observation type