Colonization of over a thousand Cibicidoides wuellerstorfi (foraminifera: Schwager, 1866) on artificial substrates in seep and adjacent off-seep locations in dysoxic, deep-sea environments

Abstract

2016-11-03T14:11:40

Epifaunal Foraminifera in an Infaunal World: Insights Into the Influence of Heterogeneity on the Benthic Ecology of Oxygen-Poor, Deep-Sea Habitats

“…Results from this study indicate that the epifaunal taxa, C. wuellerstorfi and H. nipponica, can be abundant in habitats where BWO values fall well below the upper threshold of dysoxia. Epifauna such as these are clearly not restricted to welloxygenated environments, and our results along with those of other recent studies (Burkett et al, 2016;Rathburn et al, 2018), indicate that the physiological limitations of C. wuellerstorfi, and probably other epifauna, should be expanded to include oxygenpoor environments. These results have appreciable consequences for methods that use epifauna for paleo-oxygenation indicators, and provide a greater understanding of the responses of benthic foraminiferal populations to deoxygenation.…”

“…Previous studies found C. wuellerstorfi in BWO concentrations as low as 71.5 µmol/l in the SCB (Bernhard and Reimers, 1991), and a recent global study that included specimens from the SCB, found living C. wuellerstorfi in habitats ranging from ∼2 to 277 µmol/l with abundant specimens below 45 µmol/l (Rathburn et al, 2018). A year-long study off the coast of Oregon found that over one-thousand C. wuellerstorfi had colonized hard, artificial substrates in BWO concentrations of ∼11 µmol/l (Burkett et al, 2016). In a colonization study at 4000 m off the coast of California, the epifaunal species Cibicides lobatulus, was the most abundant organism attached to glass rods after a year on the seafloor well below the lysocline (Beaulieu, 2001).…”

“…Elevated epibenthic taxa (those that live attached above the average sediment-water interface) prefer a hard substrate for attachment. C. wuellerstorfi is commonly found attached to hard surfaces at or above the sediment-water interface (e.g., Lutze and Thiel, 1989;Burkett et al, 2016). Other unattached epifauna may also prefer access to bottom water than to be surrounded by sediment and pore water.…”

“…However, relatively few studies have evaluated protoplasm-containing foraminifera from coarse-grained habitats in oxygen-poor settings. Substrate and attachment surfaces are known to be important for epifaunal foraminifera (e.g., Lutze and Thiel, 1989;Burkett et al, 2016), and increased abundances of epifaunal taxa in coarsergrained sediments has been noted in deep-water environments (Schönfeld, 2002). An understanding of the factors that influence benthic foraminifera in oxygen-poor environments is needed for high-resolution paleoceanographic studies (e.g., Stott et al, 1996;Hendy and Kennett, 2000), and to predict the responses of benthic species to deoxygenation in a globally warmer future.…”

Methane release from the southern Brazilian margin during the last glacial

“…The calcareous shells of benthic foraminifera living in cold seep habitats have more negative stable carbon isotopic ( δ 13 C) values compared to the same species living in non-seep environments (see supplementary information) 13 – 15 because of the incorporation of negative δ 13 C from ambient methane 16 . Recent laboratory culture experiments using pressure chambers to expose deep-water foraminifera species to labeled methane showed that these species can live in a methane-laden environment and that the δ 13 C of calcareous benthic foraminiferal tests are influenced by the δ 13 C signature of methane 17 .…”