Rabalais, N., Unknown, Louisiana Coastal Hypoxia Shelfwide Survey, July 1991.
This is a Point data set. It contains the following vector data types (SDTS terminology):
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0001. Longitudes are given to the nearest 0.0001. Latitude and longitude values are specified in Degrees and decimal minutes.
The horizontal datum used is WGS84.
The ellipsoid used is WGS84.
The semi-major axis of the ellipsoid used is 6378137.
The flattening of the ellipsoid used is 1/298.257223563.
| Range of values | |
|---|---|
| Minimum: | 3.18802 |
| Maximum: | 5.75249 |
| Units: | S/m |
| Range of values | |
|---|---|
| Minimum: | 8.8775 |
| Maximum: | 25.8825 |
| Units: | Density sigma-t |
| Range of values | |
|---|---|
| Minimum: | 0.003 |
| Maximum: | 60.219 |
| Units: | Meters |
| Range of values | |
|---|---|
| Minimum: | -0.3635 |
| Maximum: | 8.965 |
| Units: | volts |
Character field, generally numeric equivalent of text value except in 15 cases where "">10.0"" indicates fluorometer was maximized.
| Range of values | |
|---|---|
| Minimum: | 0.34660972 |
| Maximum: | 9.07748825 |
| Units: | mg/L |
| Range of values | |
|---|---|
| Minimum: | 5.2 |
| Maximum: | 135.7 |
| Units: | Percent |
| Range of values | |
|---|---|
| Minimum: | 36.6 |
| Maximum: | 97.5 |
| Units: | Percent |
| Range of values | |
|---|---|
| Minimum: | 17.8274 |
| Maximum: | 36.4342 |
| Units: | ppt |
Character field
| Range of values | |
|---|---|
| Minimum: | 1049 |
| Maximum: | 1231 |
| Units: | Integer |
| Range of values | |
|---|---|
| Minimum: | 19.749 |
| Maximum: | 31.6567 |
| Units: | Degrees centigrade |
| Range of values | |
|---|---|
| Minimum: | 0.0 |
| Maximum: | 60.14 |
| Units: | Meters |
| Range of values | |
|---|---|
| Minimum: | 0.2 |
| Maximum: | 64.7 |
| Units: | µg-at/L |
| Range of values | |
|---|---|
| Minimum: | 0.1 |
| Maximum: | 7.2 |
| Units: | µg-at/L |
| Range of values | |
|---|---|
| Minimum: | 0.2 |
| Maximum: | 75.6 |
| Units: | µg-at/L |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 68.4 |
| Units: | µg-at/L |
| Range of values | |
|---|---|
| Minimum: | 0.1 |
| Maximum: | 6.5 |
| Units: | µg-at/L |
| Range of values | |
|---|---|
| Minimum: | 1.3 |
| Maximum: | 44.8 |
| Units: | µg-at/L |
Character field
| Range of values | |
|---|---|
| Minimum: | 1049 |
| Maximum: | 1231 |
| Units: | Integer |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 60.14 |
| Units: | Meters |
| Range of values | |
|---|---|
| Minimum: | 0.05 |
| Maximum: | 19.04 |
| Units: | µg/L |
| Range of values | |
|---|---|
| Minimum: | 0.68 |
| Maximum: | 2.04 |
| Units: | FoFa ratio |
| Range of values | |
|---|---|
| Minimum: | 0.11 |
| Maximum: | 12.9 |
| Units: | µg/L |
Character field
| Range of values | |
|---|---|
| Minimum: | 1049 |
| Maximum: | 1231 |
| Units: | Integer |
| Range of values | |
|---|---|
| Minimum: | 0.17 |
| Maximum: | 31.94 |
| Units: | µg/L |
| Range of values | |
|---|---|
| Minimum: | 19910716 |
| Maximum: | 19910720 |
| Units: | YYYYMMDD |
| Range of values | |
|---|---|
| Minimum: | 4.5 |
| Maximum: | 62.5 |
| Units: | meters |
| Range of values | |
|---|---|
| Minimum: | 28.4998 |
| Maximum: | 29.706 |
| Units: | Decimal degrees |
| Range of values | |
|---|---|
| Minimum: | -93.5783 |
| Maximum: | -89.4748 |
| Units: | Decimal degrees |
Character field. Most depth are in meters. Stations K5 and H4 have values of >9.0m and >9.5m respectively.
Character field
| Range of values | |
|---|---|
| Minimum: | 1049 |
| Maximum: | 1231 |
| Units: | Integer |
| Range of values | |
|---|---|
| Minimum: | 0:27 |
| Maximum: | 23:15 |
| Units: | HH:mm |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 29.34 |
| Units: | meters |
Character field.
| Range of values | |
|---|---|
| Minimum: | 1062 |
| Maximum: | 1231 |
| Units: | Integer |
| Range of values | |
|---|---|
| Minimum: | 2.3 |
| Maximum: | 44 |
| Units: | mg/L |
How to obtain this tool:
Whom to contact for more information:
Tom Oswald
110 Coastal Studies Coastal Ecology Institute LSU
Baton Rouge, LA 70803
225 388-6700 (voice)
Unknown
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Turner Designs Inc.
845 W. Maude Avenue
Sunnyvale, CA 94085
US
877 316-8049 (voice)
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Wet Labs, Inc.
620 Applegate St.
Philomath, OR 97370-0518
US
541 929-5650 (voice)
How to obtain this tool:
Whom to contact for more information:
Sea-Bird Electronics, Inc.
1808 136th Place NE
Bellevue, WA 98005
USA
425 643-9866 (voice)
seabird@seabird.com
How to obtain this tool:
Whom to contact for more information:
Sea-Bird Electronics, Inc.
1808 136th Place NE
Bellevue, WA 98005
USA
425 643-9866 (voice)
seabird@seabird.com
How to obtain this tool:
Whom to contact for more information:
Sea-Bird Electronics, Inc.
1808 136th Place NE
Bellevue, WA 98005
USA
425 643-9866 (voice)
seabird@seabird.com
How to obtain this tool:
Whom to contact for more information:
Sea-Bird Electronics, Inc.
1808 136th Place NE
Bellevue, WA 98005
USA
425 643-9866 (voice)
seabird@seabird.com
How to obtain this tool:
Whom to contact for more information:
Sea-Bird Electronics, Inc.
1808 136th Place NE
Bellevue, WA 98005
USA
425 643-9866 (voice)
seabird@seabird.com
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Whom to contact for more information:
Northstar Technologies Inc.
Northstar Technologies
Acton, Mass. 01720
978-897-6600 (voice)
service@northstarcmc.co
How to obtain this tool:
Whom to contact for more information:
Wet Labs, Inc.
620 Applegate St.
Philomath, OR 97370-0518
US
541 929-5650 (voice)
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Whom to contact for more information:
Japan Radio Co. Ltd.
Akasaka Twin Tower (Main), 17-22, Akasaka 2-chome,
Minato-ku,
TOKYO, Unknown Unknown
JAPAN
81-3-3584-8836 (voice)
Rabalais, N.N., Turner, R.E. and Wiseman Jr, W.J. Funding: Funds for the research were provided by the National Oceanographic and Atmospheric Administration, Nutrient Enhanced Coastal Ocean Productivity (NECOP) program.
Nancy N. Rabalais
Louisiana Universities Marine Consortium
Louisiana Universities Marine Consortium 8124 Hwy 56
Chauvin, LA 70344
USA
985 851 2800 (voice)
985 851 2874 (FAX)
Unknown
The physical, biological and chemical data collected are part of a long-term coastal Louisiana dataset. The goal is to understand physical and biological processes that contribute to the causes of hypoxia and use the data to support environmental models for use by resource managers.
Water for chlorophyll analyses was collected from surface by bucket and bottom waters in 5 liter Niskin bottles. Water for chlorophyll analysis (50 - 100 ml) is filtered on board ship through GF/F (0.7 micron) filters, which are then fixed in 5 ml of DMSO/90% acetone (40/60) solution, allowed to extract for at least one hour in the dark, then measured pre- and post-acidification on a Turner Model 10 fluorometer.
Stations were occupied along 14 generally North-South transects across the Louisiana coastal shelf and into Texas waters. Station depths ranged from 4.5 to 62.5 meters. The objective was to delimit and describe the area of midsummer bottom dissolved oxygen less than 2 (mg/L). Northern end stations of transects were chosen based on the survey vessel's minimum depth limits for each longitude. The northern extent of hypoxia was not reached on five transects. Optimally, one or two stations South of the Southern most station with bottom dissolved oxygen less than 2 (mg/L) were sampled.
Water for nutrient analyses was collected from surface by bucket and bottom waters in 5-liter Niskin bottles. Care was taken that the collector's hands were clean and avoided touching the water. Three replicate sample vials and caps were triple rinsed with sample before vial filling and closing. Samples were not filtered. The sample vials were frozen for later analysis in the laboratory.
The CTD unit was mounted on a rosette sampler fitted with 12 5-liter Niskin bottles for recovering water samples at discrete depths.
Nitrogen and phosphorus were analyzed according to methods described in EPA publication EPA 600/4-79-020 (1979), method 350.1 for ammonia-N, method 353.2 for nitrate/nitrite-N, and method 365.1 for phosphate-P. Silicate was analyzed according to Technicon Industrial method 186-72 W/B (1977).
CTD data were post processed using Seasoft version 3.3. All scans were processed without averaging or interpolation with a bin size of one scan. Data values reported are from downcasts. Adjustment was not made to compensate for the delay in oxygen sensor response time. Downcast scans selected for each CTD station are chosen to illustrate: 1) data values as near to the surface as possible, 2) data values at whole meter increments, and 3) data values as close to the bottom as the CTD was lowered. In certain cases where data values of a parameter changed significantly between whole meter increments, 0.1 or 0.2 meter scans were selected.
Water for suspended sediment samples was collected from surface by bucket and other depths by 5-liter Niskin bottles. Water (approximately 300 to 500 ml) was filtered on board ship through pre-weighed GF/F filters. The filters were placed in Petri dishes and frozen for later analysis.
Suspended sediment filters were dried 24 hours at 40 - 60 degrees centigrade for 24 hours. Filters were weighed. Total suspended sediments was derived from volume filtered, pre-weight and post weight values.
S791Hydro: Temperature, dissolved oxygen, percent oxygen saturation, conductivity, salinity, density, percent light transmission, fluorescence and depth were acquired with a SeaBird 911 CTD system which was used to obtain water column profiles at all stations.
Oxygen concentration determinations, upper and lower end, were made prior to the cruise by the LUMCON CTD technician and entered into the SeaSoft configuration file. Winkler oxygen titrations were conducted during the cruise. A regression equation developed from Winkler titrations, demonstrated that a correction of the SeaBird oxygen data could not be determined from the range of Winkler values. Oxygen data were omitted from the top of casts if concentrations indicated that the CTD oxygen probe was not equilibrated due to inadequate "soak" time or too fast a lowering speed. Oxygen data were removed from one or more depths at 44 of the 69 the stations sampled.
Data reductions from the SeaBird were generated by Ben Cole and quality controlled by Nancy Rabalais.
Sea-Tech Fluorometer values were negative at one or more depth sampled at 39 of 69 CTD stations. Negative values imply bad connection, calibration or configuration. Fluorometer voltage data should be considered suspect.
S791Nutrient: Nutrient analyses were conducted by Tom Oswald under the supervision of R. E. Turner
S791Pigment: The Turner Designs model 10 fluorometer was calibrated for chlorophyll a against a chemical supply house chlorophyll a standard measured on a spectrophotometer yearly (or more frequently if needed). During the cruise, the Fluorometer was blanked and calibrated daily in accordance with Turner Designs recommended procedures. Chlorophyll concentrations were supervised and quality controlled by Nancy Rabalais.
S791Stns Station Depth (JRC fathometer) values are less than maximum SeaBird CTD pressure sensor depth values at stations B4, B6 and F7.
S791SuspSed: Suspended sediment concentrations were supervised and quality controlled by Nancy Rabalais
N. Rabalais performed an additional procedure in quality-control/quality-assurance by evaluating relationships between the data in S791Hydro, S791Nutrient, S791Pigment and S791Stns.
Station positions were logged from RV Pelican's NorthStar LORAN C at the beginning of sampling operations. Manufacturer's accuracy claim is 30 meters 90% of the time. Wind, currents and tidal forces may have moved the ships from the beginning positions.
Unknown.
Unknown
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- 1. Dataset credit required. 2. Experience with similar datasets has shown that when data are plotted or used in further analysis, outlying values may occasionally be discovered. Please report any possible problems with the data to N. Rabalais.
Nancy N. Rabalais
Louisiana Universities Marine Consortium
Louisiana Universities Marine Consortium 8124 Hwy 56
Chauvin, LA 70344
USA
985 851 2800 (voice)
985 851 2874 (FAX)
Unknown
I, the data requestor, agree to credit the data originators in any publications, reports or presentations generated from this data. I also accept that although these data have been processed successfully on a computer system at the Louisiana Universities Marine Consortium, no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. I recognize that these data are best acquired from the originator and not from a secondary source. I recognize that careful attention must be paid to the contents of the metadata file associated with these data. I will not hold Louisiana Universities Marine Consortium liable for improper or incorrect use of the data described and/or contained herein. This disclaimer applies both to individual use of the data and aggregate use with other data.
| Data format: | MDB (version 9) Size: 0.52 |
|---|---|
| Media you can order: |
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Ben Cole
Louisiana Universities Marine Consortium
LUMCON 8124 Hwy 24
Chauvin, LA 70344
USA
985 851 2800 (voice)
985 851 2874 (FAX)
Unknown