Long Bay ship macronutrient concentrations from R/V Savannah (SAV-12-03, SAV-12-05, SAV-12-11) cruises in the South Atlantic Bight (SAB) continental shelf off Long Bay during 2012 (Long Bay Wintertime Bloom project) (NCEI Accession 0278255)

This dataset contains chemical data collected on R/V Savannah during cruises SAV-12-03, SAV-12-05, and SAV-12-11 in the North Atlantic Ocean from 2012-01-26 to 2012-03-20. These data include Silicate, depth, nitrate plus nitrite, and reactive phosphorus (PO4). The instruments used to collect these data include CTD Sea-Bird 25, CTD profiler, Nutrient Autoanalyzer, and Sea-Bird SBE 33 Carousel Deck Unit. These data were collected by Catherine Edwards and Dr James Nelson of Skidaway Institute of Oceanography and Dr Harvey E. Seim of University of North Carolina at Chapel Hill as part of the "Mechanisms of nutrient input at the shelf margin supporting persistent winter phytoplankton blooms downstream of the Charleston Bump (Long Bay Wintertime Bloom)" project. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2021-03-01.

The following is the text of the dataset description provided by BCO-DMO:

Long Bay ship macronutrient concentrations: nitrate + nitrite, phosphate, silicate

Dataset Description:
Acquisition Description:
At selected stations and depths, Niskin water samples were collected using the ship’s CTD/carousel water sampler (Sea-Bird SBE 25 Sealogger CTD; Sea-Bird SBE 32C carousel pylon; 8-L Ocean Test Equipment Model 110 external-closure water sampling bottles). Samples were transferred to 2 L polycarbonate bottles from the Niskin bottles via Tycon tubing and processed in the ship’s wet lab. Samples for nutrients were filtered through 0.45 µm syringe filters into 100 mL acid-cleaned polyethylene screw cap bottles. Sample bottles were labelled with a numbered adhesive label and logged on a sample log sheet. Sample log sheet information was entered into a spreadsheet on a laptop. Samples bottles were frozen in the ship wet lab freezer (~ -20°C) and transferred to a shore lab freezer following the cruise.

For analyses, selected samples were shipped frozen to the MSI Analytical Lab at the Marine Science Institute of the University of California, Santa Barbara (http://msi.ucsb.edu/services/analytical-lab/instruments/flow-injection-analyzer). Analyses were conducted by Flow Injection Analysis (FIA) using a Lachat Instruments model QuikChem 8000. Analytical manifolds for Nitrate plus Nitrite, ortho-Phosphate and Silicate were employed. The analysis results were provided as a spreadsheet files (analysis date 12/14/2012). Standard checks used concentrations of 4 micromolar phosphate, 20 micromolar silicate, and 6 micromolar nitrate along with separate standards of 12 micromolar and 30 micromolar nitrate plus nitrite. Reported method detection limits were 0.10 micromolar for phosphate, 1.0 micromolar for silicate and 0.2 micromolar for nitrate plus nitrite. Sample concentrations below method detection limits were indicated in the data report.

Samples were collected from Long Bay, South Atlantic Bight, SE United States. The primary study area was 60 km in the cross-shelf extending from the middle continental shelf (~ 30 m isobath) to upper slope (~260 m) off Myrtle Beach, SC (between 33.17/-78.33 and 32.85/-78.00) and 60 km in the along-shelf.