Bahl, Alexis A; Lüskow, Florian; Décima, Moira; Steinberg, Deborah K; Pakhomov, Evgeny A: Southern Ocean Salpa thompsoni abundance day and night net data selected years spanning 4 decades (1989-2018) [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.983394 (dataset in review)
Abstract:
The salp species Salpa thompsoni was collected using depth-stratified net sampling conducted across six Southern Ocean locations during nine sampling years between 1989 and 2018. This dataset accounts for 12 day-night pairs and 10 single tows (8 daytime, 2 nighttime) collected across multiple research cruises (SO891, TAN1516, PS112, AG57, TAN0802, LMG09-01, LMG10-01, LMG11-01, LMG17-01) that were conducted in the Bransfield Strait, Chatham Rise, Elephant Island, Lazarev Sea, Ross Sea, and the Western Antarctic Peninsula. Salps were sampled using MOCNESS-1 (1 m² mouth area, 200 µm mesh), Rectangular Midwater Trawls (RMT-8, 8 m² mouth area, 4.5 mm mesh), and Juday nets (0.5 m² mouth area, 160 µm mesh), with depth-discrete sampling intervals spanning from the surface to, in some cases, 1200 m. Salp life cycle stage (LCS: blastozooid, oozoid), and occasionally developmental stage, and oral-atrial length (OAL, mm) were recorded for each individual, with salps assigned to three size classes based on maturity. For each depth stratum, abundance estimates (ind. m⁻³) were calculated by dividing the number of individuals by the volume of water filtered, then scaling by depth strata thickness if needed. This dataset comprehensively describes S. thompsoni abundance, stratified by depth, according to life cycle stage and size class, offering key insights into diel vertical distribution and regional variability.
References:
Conroy, John A; Steinberg, Deborah K; Thibodeau, Patricia; Schofield, Oscar (2020): Zooplankton diel vertical migration during Antarctic summer. Deep Sea Research Part I: Oceanographic Research Papers, 162, 103324, https://doi.org/10.1016/j.dsr.2020.103324
NOAA Global Monitoring Laboratory: NOAA Solar Calculator [web service]. https://gml.noaa.gov/grad/solcalc/ (Data retrieved on 2024-05-16)
NOAA National Centers for Environmental Information: Bathymetric Data Viewer [web service]. https://www.ncei.noaa.gov/maps/bathymetry/ (Data retrieved on 2023-12-24)
Pakhomov, Evgeny A; Hall, Julie Anne; Williams, Michael J M; Hunt, Brian P V; Stevens, Catherine J (2011): Biology of Salpa thompsoni in waters adjacent to the Ross Sea, Southern Ocean, during austral summer 2008. Polar Biology, 34(2), 257-271, https://doi.org/10.1007/s00300-010-0878-9
Perissinotto, Renzo; Pakhomov, Evgeny A (1998): Contribution of salps to carbon flux of marginal ice zone of the Lazarev Sea, southern ocean. Marine Biology, 131(1), 25-32, https://doi.org/10.1007/s002270050292
Voronina, Natalia M; Kosobokova, Ksenia Nikolaevna; Pakhomov, Evgeny A (1994): Composition and biomass of summer metazoan plankton in the 0?200 m layer of the Atlantic sector of the Antarctic. Polar Biology, 14(2), https://doi.org/10.1007/BF00234970
Funding:
Natural Sciences and Engineering Research Council (NSERC), grant/award no. RGPIN-2014-05107: Discovery grant
University of British Columbia (UBC), grant/award no. Graduate Four-Year Fellowship: University of British Columbia's Graduate Fellowship
University of British Columbia (UBC), grant/award no. International Doctoral Fellowship: International Doctoral Fellowship granted by the University of British Columbia
Coverage:
Median Latitude: -61.216008 * Median Longitude: -172.804449 * South-bound Latitude: -72.804500 * West-bound Longitude: 0.575667 * North-bound Latitude: -43.500500 * East-bound Longitude: -54.859567
Date/Time Start: 1989-03-11T11:00:00 * Date/Time End: 2018-04-29T01:39:00
Minimum ELEVATION: -4431 m a.s.l. * Maximum ELEVATION: -168 m a.s.l.
Event(s):
AGUL57_DO68 (AG57_DO68) * Latitude Start: -68.228667 * Longitude Start: 0.594167 * Latitude End: -68.260833 * Longitude End: 0.597667 * Date/Time: 1995-01-03T04:35:00 * Elevation: -4422.0 m * Location: Lazarev Sea * Campaign: AG57 (SAAMES IV cruise) * Basis: S. A. Agulhas * Method/Device: Rectangular midwater trawl 4500 µm (RMT8)
AGUL57_DO81 (AG57_DO81-82) * Latitude Start: -68.191500 * Longitude Start: 0.589667 * Latitude End: -68.164833 * Longitude End: 0.575667 * Date/Time: 1995-01-06T11:07:00 * Elevation: -4430.0 m * Location: Lazarev Sea * Campaign: AG57 (SAAMES IV cruise) * Basis: S. A. Agulhas * Method/Device: Rectangular midwater trawl 4500 µm (RMT8)
AGUL57_DO82 (AG57_DO81-82) * Latitude Start: -68.193167 * Longitude Start: 0.622167 * Latitude End: -68.168167 * Longitude End: 0.576167 * Date/Time: 1995-01-06T15:59:00 * Elevation: -4430.0 m * Location: Lazarev Sea * Campaign: AG57 (SAAMES IV cruise) * Basis: S. A. Agulhas * Method/Device: Rectangular midwater trawl 4500 µm (RMT8)
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Event label | Event | ||||
| 2 | Cruise/expedition | Expedition | Bahl, Alexis A | Unique identifier for the research cruise | ||
| 3 | Station label | Station | Bahl, Alexis A | |||
| 4 | Ocean and sea region | OS region | Bahl, Alexis A | Region | ||
| 5 | DATE/TIME | Date/Time | Bahl, Alexis A | Geocode – UTC | ||
| 6 | Date/Time local | Date/Time local | Bahl, Alexis A | UTC +/- HH:mm | ||
| 7 | UTC offset | UTC offset | Bahl, Alexis A | UTC +/- HH:mm | ||
| 8 | Year of sampling | Year sampl | Bahl, Alexis A | |||
| 9 | Day of the year | DOY | day | Bahl, Alexis A | ||
| 10 | Local Time | Local time | Bahl, Alexis A | Sunrise and sunset times extracted from the NOAA Solar Calculator using latitude, longitude, time, and date (NOAA Solar Calculator) | Local time of sunrise at the sampling location (HH:mm:ss format). | |
| 11 | Local Time | Local time | Bahl, Alexis A | Sunrise and sunset times extracted from the NOAA Solar Calculator using latitude, longitude, time, and date (NOAA Solar Calculator) | Local time of sunset at the sampling location (HH:mm:ss format). | |
| 12 | Photoperiod, hours of daylight | Photoperiod | h | Bahl, Alexis A | Photoperiod calculated as difference between sunrise and sunset times | Photoperiod was calculated as the difference between sunrise and sunset times, extracted from the NOAA Solar Calculator (https://gml.noaa.gov/grad/solcalc/; retrieved May 16, 2024) using latitude, longitude, time, and date as reference variables. |
| 13 | Time of day | Time of day | Bahl, Alexis A | Derived from sunset and sunrise | Day or night defined by local sunrise and sunset times | |
| 14 | LATITUDE | Latitude | Bahl, Alexis A | Geocode | ||
| 15 | LONGITUDE | Longitude | Bahl, Alexis A | Geocode | ||
| 16 | ELEVATION | Elevation | m a.s.l. | Bahl, Alexis A | Depth sounding or extraction from NOAA Bathymetric Data Viewer | Geocode – If bottom depth was not recorded, it was extracted from the NOAA Bathymetric Data Viewer (https://www.ncei.noaa.gov/maps/bathymetry/; retrieved December 24, 2023). |
| 17 | Gear | Gear | Bahl, Alexis A | The Rectangular Midwater Trawl (RMT-8) has a mouth opening of 8 m² and a mesh size of 4.5 mm. The multi-RMT-1+8 trawl consists of an RMT-1 (1 m² mouth area, 330 µm mesh size) and an RMT-8 (8 m² mouth area, 4.5 mm mesh size). Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS-1) is equipped with a rectangular 1 m² mouth area and nine 200 µm mesh size nets. Juday net has a 0.5 m² mouth area and a 160 µm mesh size. | ||
| 18 | Net opening | Net opening | m2 | Bahl, Alexis A | ||
| 19 | Mesh size | Mesh s | µm | Bahl, Alexis A | ||
| 20 | Net ID | Net ID | Bahl, Alexis A | Unique net identifier assigned sequentially to each sampled depth strata (between "Depth, water, bottom/minimum" and "Depth, water, bottom/maximum"). | ||
| 21 | Depth, water, top/minimum | Depth water top | m | Bahl, Alexis A | Minimum depth (upper boundary) of the sampled depth strata | |
| 22 | Depth, water, bottom/maximum | Depth water bot | m | Bahl, Alexis A | Maximum depth (lower boundary) of the sampled depth strata | |
| 23 | Pair ID | Pair ID | Bahl, Alexis A | Pair ID linking day and night stations. Paired stations (day-night pairs) are labeled as "PX", where "X" denotes the pair order across all regions. Single-tow stations are labeled as "LOCATION-DNX", where "DN" indicates whether the tow was completed during the day or night, and "X" indicates the station's sequence within that region. | ||
| 24 | Fraction of sample | Fraction sample | # | Bahl, Alexis A | Calculated | Fraction of the total sample analyzed, used for subsampling correction. The N (i.e., number of individuals) column accounts for this fraction, ensuring that abundance estimates are scaled appropriately. |
| 25 | Water volume, filtered | Vol filtered | m3 | Bahl, Alexis A | Measured or calculated | Estimated based on flowmeter readings attached to the net frame, accounting for net opening area and tow duration. If a flowmeter was unavailable, volume was estimated using ship speed, tow duration, and net mouth area. |
| 26 | Collector | Collector | Bahl, Alexis A | Responible scientist(s) | ||
| 27 | Uniform resource locator/link to reference | URL ref | Bahl, Alexis A | Articles in which some data is already published | ||
| 28 | Species, unique identification | Species UID | Bahl, Alexis A | Reference in WoRMS (WoRMS) | ||
| 29 | Species, unique identification (URI) | Species UID (URI) | Bahl, Alexis A | Reference in WoRMS (WoRMS) | ||
| 30 | Species, unique identification (Semantic URI) | Species UID (Semantic URI) | Bahl, Alexis A | Reference in WoRMS (WoRMS) | ||
| 31 | Size class | Size class | Bahl, Alexis A | Category | Categorized three size classes of each Salpa thompsoni life cycle stage based on oral-atrial length (e.g., Small, Medium, Large) and/or developmental stage. Blastozooids: Small (OAL ≤17 mm, developmental stages 0–2), Medium (18–23 mm, stages 3–4), Large (≥24 mm, stages 5, M, X); Oozoids: Small (≤50 mm, stages 0–3), Medium (51–74 mm, stages 4, 4A, 4B), Large (≥75 mm, stages 5, 5A, 5B, X). | |
| 32 | Salpa thompsoni, length | S. thompsoni l | mm | Bahl, Alexis A | Measured with calliper | Total length (TL) of the salp measured from tip to tip to the nearest millimeter. Converted to oral-atrial length (OAL). |
| 33 | Salpa thompsoni, oral-atrial length | S. thompsoni OAL | mm | Bahl, Alexis A | Measured or calculated | Measured as the straight-line distance from the oral siphon to the atrial siphon using digital calipers or a dissecting microscope with a calibrated eyepiece micrometer. If only total length (TL) was measured, the following conversion factor from Lüskow et al. (2020) was applied to derive OAL (mm): Oozoid OAL [mm] = 0.91 x TL [mm], Blastozooid OAL [mm] = 0.67 x TL [mm]. |
| 34 | Salpa thompsoni | S. thompsoni | # | Bahl, Alexis A | Counted, calculated | Number of individuals (N) counted within the net. |
| 35 | Salpa thompsoni, life stage | S. thompsoni LS | Bahl, Alexis A | Visual identification (VID) | Life Cycle Stage (LCS), either "Blastozooid" (aggregate) or "Oozoid" (solitary) stage. | |
| 36 | Salpa thompsoni, developmental stage | S. thompsoni dev stage | Bahl, Alexis A | Category | Developmental stage identifier for the individual salp, indicating reproductive or growth stages. Defined according to Foxton, 1966; Casareto and Nemoto, 1986; Chiba et al., 1999; Daponte et al., 2001. | |
| 37 | Salpa thompsoni, abundance | S. thompsoni abund | #/1000 m3 | Bahl, Alexis A | Calculated | Calculated as the number of individuals counted in the sample divided by the volume of water filtered. |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0) (License comes into effect after moratorium ends)
Status:
Curation Level: Enhanced curation (CurationLevelC)
Size:
222568 data points
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