| Processing Steps |
- 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.
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