Abstract:

This dataset contains zooplankton and ichthyoplankton data collected aboard R/V Point Sur cruise PS17_02 (PTS03) in the northern Gulf of Mexico from 2016-07-24 to 2016-07-30. Depth-discrete and surface plankton samples were collected using a Bedford Institute of Oceanography Net Environmental Sampling System (BIONESS). The BIONESS (0.25 m2 opening), a depth-discrete sampler, 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 variable freshwater discharge and low dissolved oxygen conditions characteristic of the summer. Other related station data (e.g., sampling time, station locations, oceanographic observations, etc.), net data (e.g., depth bins), and CTD profiles (temperature, salinity, depth) for BIONESS tows collected during the same cruise are available under GRIIDC Unique Dataset Identifier (UDI): R4.x260.000:0003 (DOI: 10.7266/N74T6GQD).

Suggested Citation:

Culpepper, Carla and Frank Hernandez. 2020. Zooplankton and ichthyoplankton data collected aboard R/V Point Sur cruise PS17_02 (PTS03) in the northern Gulf of Mexico from 2016-07-24 to 2016-07-30. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-0txv-z733

Purpose:

To assess the horizontal and vertical distribution, species composition, and abundance of zooplankton and ichthyoplankton under variable freshwater discharge and low dissolved oxygen conditions during the CONCORDE summer 2016 field experiment.

Data Parameters and Units:

The worksheet "Zooplankton Data": Cruise [Unique name assigned to each research cruise, PTS03]; Sample Date [Date of sample collection, mm/dd/yyyy]; Station [CONCORDE station name assigned]; Gear [Type of plankton net sampler used; BIONESS, Neuston Net, Ring Net]; Tow Number [Unique number assigned to each BIONESS tow]; Sample ID [Unique number assigned to each plankton sample]; Net [BIONESS net number]; Latitude [Latitude of sample collection, decimal degrees]; Longitude [Longitude of sample collection, decimal degrees]; Bin (m) [Nominal depth range sampled during the BIONESS tow (in meters)]; Bin Category [Categorical classification of depth bin location: oblique=whole water column; surface=upper water column; Mid=middle water column; Bottom=lower water column]; Mesh (um) [BIONESS plankton net mesh size (in micrometers)]; Swept Volume (m^3) [Volume of water filtered (m3) during plankton net tow]; Displacement Volume (mL) [Estimate of plankton biomass in mL]; Amphipod [Estimated total number of Amphipods in the sample]; Anthozoan larvae [Estimated total number of Anthozoan larvae in the sample]; Ascidian larvae [Estimated total number of Ascidian larvae in the sample]; Barnacle cypprid [Estimated total number of Barnacle cypprid in the sample]; Barnacle nauplii [Estimated total number of Barnacle nauplii in the sample]; Bivalve larvae [Estimated total number of Bivalve larvae in the sample]; Brachiopoda (lingula larva) [Estimated total number of Brachiopoda (lingula larva) in the sample]; Calanoid copepod [Estimated total number of Calanoid copepods in the sample]; Cephalopod [Estimated total number of Cephalopods in the sample]; Chaetognath [Estimated total number of Chaetognaths in the sample]; Cladoceran [Estimated total number of Cladocerans in the sample]; Copepod nauplii [Estimated total number of Copepod nauplii in the sample]; Crab megalopa [Estimated total number of Crab megalopa in the sample]; Crab zoea [Estimated total number of Crab zoea in the sample]; Ctenophores (larval) [Estimated total number of Ctenophores (larval) in the sample]; Cumacean [Estimated total number of Cumaceans in the sample]; Cyclopoid copepod [Estimated total number of Cyclopoid copepods in the sample]; Doliolid [Estimated total number of Doliolids in the sample]; Echinoderm [Estimated total number of Echinoderms in the sample]; Ectoprocta (Bryozoa larvae) [Estimated total number of Ectoprocta (Bryozoa larvae) in the sample]; Euphausiid [Estimated total number of Euphausiid in the sample]; Gastropod larvae [Estimated total number of Gastropod larvae in the sample]; Harpacticoid copepod [Estimated total number of Harpacticoid copepods in the sample]; Heteropod [Estimated total number of Heteropods in the sample]; Hydroid polyps [Estimated total number of Hydroid polyps in the sample]; Hydromedusae [Estimated total number of Hydromedusae in the sample]; Isopod [Estimated total number of Isopods in the sample]; Juvenile Crab [Estimated total number of Juvenile crabs in the sample]; Lancelet [Estimated total number of Lancelets in the sample]; Larvacean [Estimated total number of Larvaceans in the sample]; Lobster larvae [Estimated total number of Lobster larvae (phyllosoma) in the sample]; Mysid shrimp [Estimated total number of Mysid shrimp in the sample]; Nematoda [Estimated total number of Nematoda in the sample]; Ostracod [Estimated total number of Ostracods in the sample]; Other decapod [Estimated total number of Other decapods in the sample]; Parasitic copepod [Estimated total number of Parasitic copepods in the sample]; Phoronida (actinotroch larvae) [Estimated total number of Phoronida (actiontroch larvae) in the sample]; Polychaete larvae (trochophores) [Estimated total number of Polychaete larvae (trochophores) in the sample]; Polychaete [Estimated total number of Polychaetes in the sample]; Pteropod [Estimated total number of Pteropods in the sample]; Pycnogonids [Estimated total number of Pycnogonids in the sample]; Salps [Estimated total number of Salps in the sample]; Siphonophore [Estimated total number of Siphonophores in the sample]; Sipunculid [Estimated total number of Sipuncula in the sample]; Stomatopod [Estimated total number of Stomatopods in the sample]; Tanaid [Estimated total number of Tanaids in the sample]; Tornaria Larvae [Estimated total number of Torria Larvae in the sample]; and Unidentified organisms [Estimated total number of Unidentified organisms in the sample]. The worksheet "Ichthyoplankton Data": Cruise [Unique name assigned to each research cruise, PTS03]; Sample Date [Date of sample collection, mm/dd/yyyy]; Station [CONCORDE station name assigned]; Gear [Type of plankton net sampler used; BIONESS, Neuston Net, Ring Net]; Tow # [Unique number assigned to each BIONESS tow]; Sample ID [Unique number assigned to each plankton sample]; Latitude [Latitude of sample collection, decimal degrees]; Longitude [Longitude of sample collection, decimal degrees]; Net [BIONESS net number]; Bin (m) [Nominal depth range sampled during the BIONESS tow (in meters)]; Mid=middle water column; Bottom=lower water column]; Mesh (um) [BIONESS plankton net mesh size (in micrometers)]; Swept Volume (m^3) [Volume of water filtered (m3) during plankton net tow]; Displacement Volume (mL) [Estimate of plankton biomass in mL]; Total Fish [Estimated number of fish larvae (all taxa) in the sample]; Total Eggs [Estimated number of fish eggs in the sample]; Family [Identification to the lowest taxonomic classification]; Standard Length (mm) 1 - 10 [Standard length of specimen (unless noted with NL, then used notochord length)]; Measured [The total number of individual larval fish by taxa measured]; Not Measured [The total number of individual larval fish by taxa not measured]; Total [The total number of individual larval fish by taxa]; and Comments [Comments by ichtyhoplankton taxonomist]. The file "GRIIDC_Cruise_Data_Documentation_PTS03" is the cruise documentation with the cruise information for the R/V Point Sur cruise PS17_02 (CONCORDE cruise PTS03) led by chief scientist Dr Christian Briseño-Avena. Please note that that the heading “Bin Category” is not applicable to “Ichthyoplankton Data”.

Methods:

Zooplankton Processing: Plankton displacement volume was determined following the methods outlined in the ICES (International Council for the Exploration of the Sea) Zooplankton Methodology Manual. 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: 1) Total number in sample = Taxon count x (Count Volume / Zooplankton Aliquot) x Sample Aliquot 2) 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. Ichthyoplankton Processing: 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:

Harris, Roger, Peter Wiebe, Jurgen Lenz, Hein Rune Skjoldal, and Mark Huntley. (Eds.). (2000). ICES zooplankton methodology manual. Elsevier. https://doi.org/10.1016/B978-0-12-327645-2.X5000-2

Individual Files: