CTD, water quality, plankton species abundance, quantitative phytoplankton profiles and chlorophyll a and b concentrations in sediment samples data collected from R/V Bellows cruise BE-1212 in the northern Gulf of Mexico from 2011-05-21 to 2013-09-16 (NCEI Accession 0175053)

For this, one-liter samples were collected from the surface and at different depths using Niskin bottles. Samples were filtered onto a 0.45 micrometer nitrocellulose filter and air-dried. A portion of each filter was mounted on an aluminum stub, sputter-coated, and examined with a JEOL JSM-6480 LV scanning electron microscope.

Diatoms, coccolithophores, and armored dinoflagellates were identified to the lowest possible taxonomic category. The number of cells of each taxon in a field of view at a magnification of 1000x was recorded, with up to 700 fields-of-view examined, depending on the density of phytoplankton in the sample. Similarly, sediment samples were collected using replicate Shipek sediment grabs from 28 samples sites between 2011-05-21 and 2013-09-16.

Sediment was frozen in the field for transfer to the laboratory. Once in the laboratory, samples were acetone extracted and fluorescence was determined on a Perkin Elmer scanning fluorometer. Standard chlorophyll preparations were used for sample quantification.