Living deep-sea benthic foraminifera from the Cap de Creus Canyon (western Mediterranean): Faunal-geochemical interactions
Contreras-Rosales, L.A.; Koho, K.A.; Duijnstee, I.A.P.; de Stigter, H.C.; García, R.; Koning, E.; Epping, E. (2012). Living deep-sea benthic foraminifera from the Cap de Creus Canyon (western Mediterranean): Faunal-geochemical interactions. Deep-Sea Res., Part 1, Oceanogr. Res. Pap. 64: 22-42. dx.doi.org/10.1016/j.dsr.2012.01.010 In: Deep-Sea Research, Part I. Oceanographic Research Papers. Elsevier: Oxford. ISSN 0967-0637; e-ISSN 1879-0119, more |  |
| Keyword | | | Author keywords | Benthic foraminifera; Redox chemistry; Submarine canyons; Sedimentaryphytopigments |
| Authors | | Top | - Contreras-Rosales, L.A.
- Koho, K.A.
- Duijnstee, I.A.P.
- de Stigter, H.C., more
| - García, R.
- Koning, E., more
- Epping, E., more
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| Abstract | Rose-Bengal-stained benthic foraminifera were sampled along a depth transect from the Cap de Creus Canyon and the adjacent slope. Well-stained individuals were studied in the top 5 cm of sediment and the faunal abundances and assemblages were compared against pore-water geochemistry and biochemical composition of the sediment. Total standing stocks (TSS) of foraminifera were positively correlated with the chloroplastic pigment equivalents inventory (CPEinv; here interpreted as food quantity) and the ratio of chlorophyll-a and phaeopigment inventories (Chl-a(inv)/Phaeo(inv); here interpreted as food quality), suggesting food quality as well as quantity play an important role in structuring the foraminiferal community. Food quality and food quantity were also identified by detrended correspondence analyses (DCA) as being the most important environmental parameters shaping the foraminiferal community structure (abundance and faunal composition). In addition, sediment redox chemistry (based here on pore-water nitrate) played an important role in controlling the foraminiferal diversity (H') as a negative correlation was seen between this parameter and pore-water nitrate penetration depth (NPD). No conclusive evidence of intense physical disturbance on the benthic canyon community was observed, although it could be anticipated in the area due to shelfwater downwelling (SWD) and dense shelf-water cascading (DSWC). However, foraminiferal faunas living in the canyon head and upper canyon environments may profit from the higher organic-matter availability, which is likely to be related to SWD and DSWC. The similarity between the deeper canyon and slope faunas suggests that sediment characteristics and the associated organic-matter transported by SWC and DSWC do not have a permanent effect at these depths. |
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