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Düsedau, Luisa; Fredriksen, Stein; Brand, Markus; Fischer, Philipp; Karsten, Ulf; Bischof, Kai; Savoie, Amanda; Bartsch, Inka: Semi-quantitative macroalgae survey on abundance and lower depth distribution of dominant brown algal species collected at Hansneset, Kongsfjorden, Spitsbergen in 2021 [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.963583 (dataset in review)

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Abstract:
Surveys were performed of abundance and lower depth distribution of biomass dominant brown algae species at Hansneset, Blomstrand in Kongsfjorden, Svalbard, between 2 m and 20 m depth in June - August 2021. This dataset is part of a time series currently spanning over 25 years and complements the studies conducted in 1996/98 (Hop et al., 2012, doi:10.1515/bot-2012-0097) and 2012-14 (Bartsch et al., 2016, doi:10.1007/s00300-015-1870-1). The aim was to document changes in Arctic kelp forests dynamics in an Arctic fjord system influenced by glacial melt by repeatedly sampling the same site in a standardized manner. As ocean temperatures in the Arctic have risen substantially and underwater light climate continuously deteriorated over this time period alterations were observed in the seaweed community, especially kelps as major coastal foundation species.
The depth distribution of biomass dominant brown algae was semi-quantitatively (visually) investigated by scientific divers in five parallel transects off the coastline covering the vertical gradient between 2 m and 20 m depth. For each replicate a 1x1 m quadrat divided into four 50 x 50 cm subquadrats was placed on the ground or above the kelps at every depth meter along the transect and species occurrence was documented as attached frequency within each subquadrat. This resulted in a relative frequency of 0 - 4 per replicate (Frequency count). Additionally, the visual presence of the species in the close surroundings of each replicate was documented 0 or 1 (Additional Presence). In summary this generates in a maximum presence score of 5 for each species per replicate. The target replication was five per depth but due to depth corrections to chart datum this resulted in n = 3–8 for each depth and species. The presence (1) or absence (0) of rocks, pebbles, and/or sand was all documented.
Keyword(s):
Biomass; Depth transect; kelp forest; leaf area index (LAI); Svalbard
Supplement to:
Düsedau, Luisa; Fredriksen, Stein; Brand, Markus; Fischer, Philipp; Karsten, Ulf; Bischof, Kai; Savoie, Amanda; Bartsch, Inka (in prep.): Arctic kelp forest decline - a consequence of melting glaciers? Ecology and Evolution
References:
Bartsch, Inka; Paar, Martin; Fredriksen, Stein; Schwanitz, Max; Daniel, Claudia; Hop, Haakon; Wiencke, Christian (2016): Changes in kelp forest biomass and depth distribution in Kongsfjorden, Svalbard, between 1996–1998 and 2012–2014 reflect Arctic warming. Polar Biology, 16 pp, https://doi.org/10.1007/s00300-015-1870-1
Hop, Haakon; Wiencke, Christian; Vögele, Barbara; Kovaltchouk, Nikolaj A (2012): Species composition, zonation, and biomass of marine benthic macroalgae in Kongsfjorden, Svalbard. Botanica Marina, 55(4), 399-414, https://doi.org/10.1515/bot-2012-0097
Project(s):
Coverage:
Latitude: 78.995800 * Longitude: 11.987200
Date/Time Start: 2021-06-21T00:00:00 * Date/Time End: 2021-06-23T00:00:00
Minimum DEPTH, water: 2.13 m * Maximum DEPTH, water: 20.77 m
Event(s):
Hansneset_KELP_2021 * Latitude: 78.995800 * Longitude: 11.987200 * Method/Device: Observation (OBSE) * Comment: Observation between June - August 2021
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethod/DeviceComment
1DATE/TIMEDate/TimeDüsedau, LuisaGeocode
2Transect numberTransect noDüsedau, Luisa
3DEPTH, waterDepth watermDüsedau, LuisaGeocode
4LevelLevelmDüsedau, LuisaDepth leve
5Presence/absencePresence/absenceDüsedau, LuisaVisual descriptionPebbles
6Presence/absencePresence/absenceDüsedau, LuisaVisual descriptionRock
7Presence/absencePresence/absenceDüsedau, LuisaVisual descriptionSand
8SpeciesSpeciesDüsedau, LuisaSpecies and comment
9Species, unique identificationSpecies UIDDüsedau, Luisa
10Species, unique identification (Semantic URI)Species UID (Semantic URI)Düsedau, Luisa
11Species, unique identification (URI)Species UID (URI)Düsedau, Luisa
12CountsCounts#Düsedau, LuisaCounted
13CoverageCov%Düsedau, LuisaEstimated
14Presence/absencePresence/absenceDüsedau, LuisaVisual descriptionAdditional species presence
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:
5000 data points

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