Sample collection: Net tows and mid-water trawls were conducted in the western Ross Sea, Antarctica on board the R/V Nathaniel B. Palmer in January-February 2018 (cruise number 18-01). Both the ring net (1 m diameter, 333 um mesh, non-filtering cod end) and the Issacs-Kidd Midwater Trawl (IKMT, 1.8 m frame, 500 um mesh, non-filtering cod end) were fitted with a calibrated General Oceanics flow meter. Contents of each tow were concentrated and preserved with buffered formaldehyde (4% final concentration) in 500 ml wide-mouth glass jars. Samples were sent back to the home laboratory (Rutgers University) for analysis.
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Analyses: Contents of each tow (or a subsample if the density of zooplankton or fish was high) were sorted by taxa and, in some cases, developmental stage. Measurements for abundance were conducted using a dissecting microscope (Zeiss Discovery.V8).
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Volume of water (cubic meter) that passed through the net/trawl during each tow was calculated using flowmeter rotor constant, flowmeter start and end values, and the area of net opening.
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Abundance per cubic meter per tow/trawl was then calculated for each species and, in some cases, developmental stage, by dividing the number of individuals for each species/developmental stage by the volume of water.
Isaacs-Kid Midwater Trawl (IKMT) hauls were conducted during the R/V Nathaniel B. Palmer cruise NBP18-01 in Jan-Feb 2018. These data represent the zooplankton species and abundance analysis resulting from these sample collections. A companion dataset of ring net tow\u00a0abundances is also available.
BCO-DMO Processing Notes:
\nversion 1:
\n- added conventional header with dataset name, PI name, version date
\n- modified parameter names to conform with BCO-DMO naming conventions
\n- in Method column, replaced commas with semicolons
\n- converted latitudes and longitudes\u00a0to decimal degrees
\n- two columns were named 'Latitude end'; renamed second one 'lon_end_decdeg' as it's clearly a longitude.
\n- reformatted start and end date and times to\u00a0ISO-format (from m/d/yy to yyyy-mm-ddTHH:MM:SSZ)
\nversion 2:
\n- same as v1 - changes didn't 'take'.
\nversion 3:
\n-\u00a0corrected ISO_DateTime_UTC by removing an extra \":00\" at end of the string (eg.\u00a02018-01-10T02:04:00:00Z)
\nversion 4:\u00a0
\n- revised volume filtered and zooplankton abundance values.