Publication Date:
2023-07-10
Description:
Fjords have been described as hotspots for carbon burial, potentially playing a key role within the carbon cycle as climate regulators over multiple timescales. Nevertheless, little is known about the long-term fate of the carbon that may become stored in fjordic sediments. One of the main reasons for this knowledge gap is that carbon arriving on the seafloor is prone to post-depositional degradation, posing a great challenge when trying to discriminate between an actual change in carbon deposition rate and post depositional carbon loss. In this study, we evaluate the use of modern benthic foraminifera as bio-indicators of carbon content in six voes (fjords) on the west coast of Shetland. Benthic foraminifera are sensitive to changes in carbon content in the sediments, and changes in their assemblage composition therefore reflect synchronous variations in the quantity and quality of carbon reaching the seafloor. We identified four environments based on the relationship between benthic foraminiferal assemblages and carbon content in the sediments: 1) Land-locked regions influenced by riverine/freshwater inputs of organic matter, namely the head of fjords with a restricted geomorphology; 2) Stressed environments with a heavily stratified water column and sediments rich in organic matter of low nutritional value; 3) Depositional environments with moderate organic content and mild or episodic current activity; 4) Marginal to coastal settings with low organic content, such as fjords with an unrestricted geomorphology. We conclude that foraminifera potentially provide a tool to disentangle primary carbon signals from post-depositional degradation and loss of carbon because of their environmental sensitivity and high preservation potential in the sedimentary record.
Keywords:
Aith Voe, Shetland; Ammonia spp.; Ammoscalaria runiana; Benthic foraminifera assemblages; Bolivina pseudoplicata; Bolivina pseudopunctata; Bolivina skagerrakensis; Bolivina spathulata; Bolivina variabilis; Buccella frigida; Buccella tenerrima; Bulimina elongata; Bulimina gibba; Bulimina marginata; Buliminella elegantissima; Busta Voe, Shetland; Cassidulina laevigata; Cassidulina obtusa; Cibicides spp.; Clift Sound, Shetland; Connemarella rudis; Cornuspira sp.; Counting 〉63 µm fraction; DEPTH, sediment/rock; Discanomalina sp.; Eggerelloides scaber; Elphidium aculeatum; Elphidium albiumbilicatum; Elphidium crispum; Elphidium excavatum; Elphidium gerthi; Elphidium incertum; Elphidium margaritaceum; Elphidium sp.; Elphidium williamsoni; Epistominella vitrea; Event label; Fissurina spp.; Foraminifera, benthic indeterminata; Globobulimina affinis; Haplophragmoides sp.; Haynesina germanica; Hyalinea balthica; Lagena clavata; Lagena semistriata; Lagena setigera; Lamarckina heliotidea; Latitude of event; Longitude of event; MD15-01; MD15-02; MD15-03; MD15-04; MD15-05; MD15-06; MD15-07; MD15-08; MD15-09; MD15-10; MD15-11; MD15-12; MD15-13; MD15-14; MD15-15; MD15-16; MD15-17; MD15-18; MD15-19; MD15-20; MD15-21; Miliolinella subrotunda; Nonion depressulum; Nonionella turgida; Nonion porporatum; Number of species; Olna Firth, Shetland; Oolina hexagona; Oolina melo; Oolina sp.; Oolina squamosa; Oolina williamsoni; Patellina corrugata; Planorbulina distoma; Quinqueloculina bicornis; Quinqueloculina seminulum; Quinqueloculina sp.; Reophax fusiformis; Reophax scotti; Rosalina anomala; Rosalina sp.; Sample ID; Sand Sound, Shetland; Spirillina vivipara; Spiroloculina rotunda; Spiroplectinella wrightii; Stainforthia fusiformis; Textularia earlandi; Trifarina angulosa; Trochammina sp.; Vaila Sound, Shetland; van Veen Grab; VGRAB
Type:
Dataset
Format:
text/tab-separated-values, 1521 data points
