Abstract:

This dataset contains zooplankton and ichthyoplankton data collected aboard the R/V Point Sur (cruise PTS02) in the northern Gulf of Mexico from 2016-03-30 to 2016-04-10. Depth-discrete and surface plankton samples were collected during CONCORDE using a Bedford Institute of Oceanography Net Environmental Sampling System (BIONESS). The BIONESS (0.25 m2 opening) is a depth-discrete sampler that was fitted with six 333-µm mesh nets and three 202-µm mesh nets. Biological samples were collected generally between the 15 and 40 m depth contours between the Chandeleur Islands and the Alabama/Florida border to assess the horizontal and vertical distribution, species composition, and abundance of zooplankton and ichthyoplankton under high freshwater discharge conditions characteristic of the spring season. The dataset contains the date, latitudes, and longitudes of the sampling location.

Suggested Citation:

Culpepper, Carla and Frank Hernandez. 2021. Zooplankton and ichthyoplankton data collected aboard the R/V Point Sur (cruise PTS02) in the northern Gulf of Mexico from 2016-03-30 to 2016-04-10. Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-5fhx-ph26

Purpose:

Data collection of zooplankton and ichthyoplankton in the northern Gulf of Mexico to assess the horizontal and vertical distribution, species composition, and abundance of zooplankton and ichthyoplankton under high freshwater discharge conditions characteristic of the spring season.

Data Parameters and Units:

The cruise documentation was provided for the R/V Point Sur (cruise PTS03). The cruise was led by chief scientists Dr. Alison Deary and Dr. Adam Greer. Zooplankton Data tab: Cruise (PTS02), Sample, Date, Station (ECORR/MCORR/WCORR/PROCESS), Gear (BIONESS), Tow#, Sample ID, Latitude, Longitude, Net, Bin (m), Bin Category (Bottom/Mid/Surf/Oblique), Mesh (um) (335/202), Swept Volume (m^3), Displacement Volume (mL), Amphipod, Amphipod, Anthozoan larvae, Ascidian larvae, Barnacle cyprid, Barnacle nauplii, , Bivalve larvae, Brachiopoda (lingula larvae), Calanoid Copepod, Cephalopod, Chaetognath, Cladoceran, Copepod nauplii, Crab megalopa, Crab zoea, Ctenophores (larval), Cumacean, Cyclopoid Copepod, Doliolid, Echinoderm, Ectoprocta (Bryozoa larvae, Euphausiid, Gastropod larvae, Harpacticoid Copepod, Heteropod, Hyrdroid Polyp, Hydromedusae, Isopod, Juvenile crab, Lancelet, Larvacean, Lobster Larvae, Mysid Shrimp, Nematoda, Ostracod, Other decapod, Parasitic Copepod, Phoronida (actiontroch larvae), Polychaete, Polychaete larvae (trochophores), Pteropod, Pycnogonid, Salp, Siphonophore, Sipunculid, Stomatopod, Tanaid, Tornaria, Unidentified. Ichtyhoplankton Data tab: Cruise (PTS02), Sample Date, Station (ECORR/MCORR/WCORR/PROCESS), Gear (BIONESS), Tow #, Sample ID, Latitude, Longitude, Net, Bin (m), Bin Category (Mid/Bottom/Surf), Mesh (um) (335/202), Swept Volume (m^3), Displacement Volume (mL), Total Fish, Total Eggs, Family, Standard Length (mm), Measured, Not Measured, Total

Methods:

Plankton displacement volume was determined following the methods outlined in the ICES Zooplankton Methodology Manual (2000, Eds. R. Harris, P. Wiebe, J. Lenz, H.-R. Skjoldal and M. Huntley). Samples greater with displacement volumes > 60 mL were further split to generate "sample aliquots", of which one was selected for further processing. The sample aliquot for sorting was poured into a 1000 mL graduated pitcher, and the volume was adjusted to a total of at least 200 mL but no more than 500 mL; this "count volume" was recorded. The aliquot was then stirred and aerated for 1 minute to ensure homogeneity. After aerating, an aliquot using a Stempel Pipet was taken and the "zooplankton aliquot" volume was recorded. The ideal aliquot should be enough to provide a count of at least 200 copepods and 200 of the other organisms combined, but small enough to prevent going over 500 for either. All organisms in the aliquot were counted ("taxon count"). The aliquot was then set aside for quality assurance/quality control by another taxonomist. From every set of 10 sample aliquot counts processed by an individual, one counted aliquot was randomly selected and recounted by someone other than the original taxonomist. Two requirements must be fulfilled to pass the QA/QC process: 1) Copepod abundances and total non-copepod abundances must be no more than 10% different or no less than 90% the same. 2) The top 90% of organisms ranked by abundance should be in the same order for the initial sorter and the QA/QC sorter. Exceptions include reversing ranks based on abundances that are within 5% of one another. If the selected aliquot failed, another sample was randomly selected from the same batch and examined. If the second aliquot fails, the entire batch of 10 was re-counted. The total number of each zooplankton taxon for each sample (the column values in the data set for each taxon) was then estimated using the following equation: Total number in sample = Taxon count x (Count Volume / Zooplankton Aliquot) x Sample Aliquot The density (number per cubic meter) of each taxon can then be derived by dividing the column values for each taxon by the swept volume. Fish eggs were sorted from the samples and enumerated; fish larvae were sorted from the samples, identified to the lowest possible taxonomic level, and enumerated.

Provenance and Historical References:

ICES Zooplankton Methodology Manual (2000, Eds. R. Harris, P. Wiebe, J. Lenz, H.-R. Skjoldal and M. Huntley).

Individual Files: