Show more...
Abstract:
Summary:
The data was collected during the Nansen Legacy Joint Cruise 2-2 (JC2-2) 24th August - 29th September 2021 on the research vessel RV Kronprins Haakon (cruise number 2021710) on the research vessel RV Kronprins Haakon, along a transect from 82 N in the Nansen Basin across the Gakkel Ridge to 87.5 N in the Amundsen Basin. The dataset contains mesozooplankton occurrence. It has been sampled using a MultiNet Midi at 5 distinct depths. Small mesozooplankton were collected with a mesh-size 64 µm and large mesozooplankton were collected with a mesh-size 180 µm. All specimens are identified to the lowest taxonomical level and the occurrence is given for a specific species and stage or size group as ind/m3.
Sampling method:
The sampling covers a transect from 82 N in the Nansen Basin across the Gakkel Ridge to 87.5 N in the Amundsen Basin. Each sampling event includes 5 distinct depth layers; bottom-600, 600-200, 200-50, 50-20 and 20-0 m. Zooplankton has been collected using a Multinet Midi (HydroBios, opening: 0.25m2, net length: 250 cm). Small mesozooplankton were collected with a mesh-size 64 µm and large mesozooplankton were collected with a mesh-size 180 µm. All samples were preserved in 4 % formaldehyde free from acid. In addition, a Multinet Mammoth with 180 µm mesh-size was deployed at the southernmost station (P7, 2000-1500, 1500-1000, 1000-600, 600-200, 200-50, 50-20, 20-0m) and the northernmost station (P11, 3000-2000, 2000-1500, 1500-600, 600-400, 400-200, 200-50, 50-20, 20-0m). The different depth layers were due to problems with the closing of one of the nets.
PLEASE NOTE: THIS DATASET CONTAINS TWO COMPLETE DATASETS OF ZOOPLANKTON: ONE FOR SMALL MESOZOOPLANKTON (APPROX BODY SIZE BELOW 2 MM) COLLECTED WITH MULTINET 64 µM AND ONE FOR LARGE MESOZOOPLANKTON (APPROX BODY SIZE ABOVE 2 MM) COLLECTED WITH MULTINET 180 µM MESH SIZE. THE INFO ABOUT WHICH NET IS USED CAN BE FOUND IN gearType. USE EITHER 64 UM OR 180 UM DEPENDING ON WHETHER THE FOCUS IS SMALL OR LARGE MESOZOOPLANKTON.
Analyse method:
All samples have been analysed at Institute of Oceanology of the Polish Academy of Sciences (IOPAN). The organisms were identified and counted under a stereomicroscope equipped with an ocular micrometer, according to standard procedures (Harris et al. 2000). Small-sized zooplankters (most of Copepoda, juvenile stages of Pteropoda, Euphausiacea, Ostracoda, Amphipoda and Chaetognatha) were identified and counted in sub-samples obtained from the fixed sample volume by automatic pipette (approximately 500 individuals). Large zooplankters (big Copepoda, Pteropoda, Euphausiacea, Ostracoda, Amphipoda, Decapoda, Appendicularia, Chaetognatha, and Pisces larvae) were sorted out and identified from the whole sample. Representatives of Calanus spp. were identified at the species level based on morphology and prosome lengths of individual copepodid stages (Kwasniewski et al. 2003).
Data structure:
The data is following Darwin Core nomenclature as far as possible but also include variables that aren’t supported by Darwin Core. All information about the sampling such as eventDate, latitude, longitude, depts etc is located in event file while the results such as scientificName, lifeStage, occurrence etc. are found in the occurrence file
Header name index - events
-
expedition: cruise number for R/V Kronprins Haakon
-
eventID: UUID for the sample
-
parentID: UUID for the gear deployment (each MultiNet deployment has a unique parentID)
-
eventDate: the date-time when an event occurred, using ISO 8601-1:2019 format (2020-07-27T07:16:03.446Z).
-
fieldNumber: human-readable sample ID (e.g. ZOT-001)
-
locationID: station name
-
decimalLongitude: geographic latitude (in decimal degrees, using the spatial reference system given in geodetic datum)
-
decimalLatitude: geographic longitude (in decimal degrees, using the spatial reference system given in geodeticDatum)
-
bottomDepthInMeters: bottom depth in meters
-
eventRemarks: comments or remarks about the event (free text field)
-
gearType: the gear used to take the sample e.g. MultiNet 200 µm
-
maximumDepthInMeters: bottom depth of the sampled layer
-
minimumDepthInMeters: top depth of the sampled layer
-
sampleType: description of the sample type according to a standard list
-
fieldSplit: info about whether the sample is splitted. If the sample was split in 2 then fieldSplit = 2
-
flowmeterStart: only recorded if a flowmeter is used
-
flowmeterStop: only recorded if a flowmeter is used
-
initialSampleVolume: The volume of water filtered through the plankton net. The initial sample volume can be calculated in three ways and should always divided by fieldSplit if the sample is split.
-
theoreticalSampleVolume: Calculated based on sample layer thickness and net opening area (initialSampleVolume = netOpeningArea * (maximumDepthInMeters – minimumDepthInMeters)) Bongonet opening area: 3.14*(0.3)^2=0.2826 m2 WP2 opening area: 3.14*(0.285)^2 = 0.2550 m2 Multinet Midi opening area: 0.25 m2
-
flowmeterSampleVolume: Calculated based on flow-meter readings (initialSampleVolume= (flowmeterStart- flowmeterStop )*( flowmeter pitch = meters/revolution )*netOpeningArea)
-
regressionMultiNetVolume: Calculated based on regression for MultiNet samples (initialSampleVolume = -1.2681+(0.3298*(maximumDepthInMeter – minimumDepthInMeter))
-
initialVolumeMethod: description of which of the three methods were used to calculate the initialSampleSizeValue
-
recordedBy: name of the person who took the samples
-
principalInvestigatorName: name of the person in charge of the sample collection
-
principalInvestigatorEmail: email address of the person in charge of the sample collection
-
principalInvestigatorInstitution: affiliated institution of the person in charge of the sample collection
Header name index - occurrence
- analysedFraction: fraction of the sampled volume that is examined for organism counted
- individualCount: the number of individuals present in the analysed volume (see extra information below)
- scientificName: full scientific name of the identified organism at the lowest taxonomic level that can be ascertained. The scientificName should be selected from a drop-down menu linked to the list in taxonomy sheet. (e.g Calanus finmarchicus).
- identificationQualifier: A standard term (sp., spp., and indet.) to express the determiner’s doubts about the Identification.
- lifeStage: the age class, life stage, or life form/morph of the organism.
- sizeGroupOperator: describes if the size group is less than or greater than a value (It = less than, gte = greater or equal to)
- sizeGroup: the size group in mm.
- organismRemark: indicates whether it is mesozooplankton, macrozooplankton, rare species
- identificationRemarks: a free text field for adding information relevant to the analysis
- identifiedBy: person who did the lab-analyse
- sampleSizeValue: the sample volume used to calculate the organismQuantity (sampleSizeValue 0 initialSampleVolume *analysedFraction)
- sampleSizeUnit: m3
- organismQuantity: the quantity of the organism per volume water in the environment (organismQuantity = individualCount/sampleSizeValue)
- organismQuantityType: ind/m3
Additional information for some of the fields
individualCount: The number of (all) organisms found in the sample examined
- for “mesozooplankton”, the number of mesozooplankton (medium size zooplankton organisms) encountered in all sub-samples
- for “macrozooplankton”, the number of macrozooplankton (large size zooplankton organisms, total length > 5 mm) encountered, identified in the entire sample
- for “rare” zooplankton, we only enter information about the finding of “rare” zooplankton in the database template, and its absolute number (“organismQuantity”) is not estimated
Funding:
The Nansen Legacy is funded by the Research Council of Norway and the Norwegian Ministry of Education and Research. They provide 50% of the budget while the participating institutions contribute 50% in-kind. The total budget for the Nansen Legacy project is 740 mill. NOK.