Showing papers by "Frans Jorissen published in 2012"
TL;DR: The aim is to standardise methodologies used in bio-monitoring only and not to limit the use of different methods in pure scientific studies, and to propose two types of recommendations about living (stained) benthic foraminiferal assemblages.
366 citations
TL;DR: Improved knowledge of deep-sea foraminiferal biogeography requires sound morphology-based taxonomy combined with molecular genetic studies, and endemism may be more prevalent than currently realized.
Abstract: Benthic foraminifera, shell-bearing protists, are familiar from geological studies. Although many species are well known, undescribed single-chambered forms are common in the deep sea. Coastal and sublittoral species often have restricted distributions, but wide ranges are more frequent among deep-water species, particularly at abyssal depths. This probably reflects the transport of tiny propagules by currents across ocean basins that present few insurmountable barriers to dispersal, combined with slow rates of evolution. Undersampling of the vast deep-sea habitat, however, makes it very difficult to establish the ranges of less common foraminiferal species, and endemism may be more prevalent than currently realized. On continental slopes, some species have restricted distributions, but wide-ranging bathyal species that exhibit considerable morphological variation are more common. This may be linked to the greater heterogeneity of continental slopes compared with oceans basins. Improved knowledge of deep-sea foraminiferal biogeography requires sound morphology-based taxonomy combined with molecular genetic studies.
112 citations
TL;DR: In this article, dead benthic foraminiferal assemblages were studied in the >150μm fraction of 4-5 cm deep sediment levels at 18 stations in the Whittard Canyon area in June 2007.
43 citations
TL;DR: In this article, live benthic foraminifera were studied in eight cores collected along a depth transect ranging 282-4987 m on the Portuguese margin, and three groups of stations were distinguished: (1) eutrophic upper-slope stations (282-1002 m) with faunas dominated by Uvigerina mediterranea, U. elongatastriata, Melonis barleeanus, Bigenerina nodosaria, Trifarina bradyi, Epistominella vitrea, Cribrost
Abstract: Live benthic foraminifera were studied in eight cores collected along a depth transect ranging 282-4987 m on the Portuguese margin. Total standing stocks (TSS) and species assemblages from both 63-150- and >150-mu m fractions are compared between stations along the transect and with previous live foraminiferal studies from the Bay of Biscay and western Iberian margin. Based on the sedimentary organic matter contents and ecological traits of the retrieved foraminifera, three groups of stations are distinguished: (1) eutrophic upper-slope stations (282-1002 m) with faunas dominated by Uvigerina mediterranea, U. elongatastriata, Melonis barleeanus, Bigenerina nodosaria, Trifarina bradyi, Epistominella vitrea, Cribrostomoides bradyi, and Bolivina robusta, (2) mesotrophic middle- to lower-slope stations (1374-2475 m) with faunas dominated by Uvigerina peregrina, Globobulimina affinis, and Repmanina charoides, and (3) oligotrophic lower-slope and abyssal-plain stations (2908-4987 m) with faunas in the larger size fraction dominated by Cibicides kullenbergi and agglutinated species such as Reophax fusiformis and Recurvoides sp. 1. The smaller size fraction is dominated by opportunistic calcareous species such as Bulimina translucens, Epistominella exigua, and Nuttallides pusillus, along with Reophax fusiformis, but most of these species are diminished at 4987 m, where Reophax fusiformis, Pullenia salisburyi, and various monothalamous agglutinates are dominant. This succession of assemblages probably reflects the increasing scarcity of trophic resources with water depth. This hypothesis is corroborated by 1) the clear decrease of TSS with increasing water depth, and 2) the decreasing sediment phytopigment concentrations towards deeper sites. Moreover, the decreasing percentage of perforate calcareous foraminifera, and increasing percentage of agglutinated foraminifera with water depth, suggests that, in general, perforate calcareous species have higher trophic requirements than agglutinated ones.
40 citations
TL;DR: The first results show that foraminifera have a strong physiological response to a 30-day incubation with high concentrations of all tested pollutants, and NABM (non aqueous based mud) has a higher toxicity than WBM (water based mud).
38 citations
TL;DR: In this paper, a shallow water benthic foraminiferal species Ammonia tepida was cultured in controlled temperature conditions (20°C) at three different salinities (29.8, 32.2, and 35.5).
29 citations
TL;DR: In this article, a new Mg/Ca-temperature calibration for the benthic foraminifer Bulimina marginata, based on cultures under a range of temperatures (4-14 ° C), was presented.
Abstract: The reconstruction of past temperatures is often achieved through measuring the Mg/Ca value of foraminiferal test carbonate. The diversity in foraminiferal Mg/Ca-temperature calibrations suggests that there is also a biological control on this proxy. This study presents a new Mg/Ca-temperature calibration for the benthic foraminifer Bulimina marginata, based on cultures under a range of temperatures (4-14 ° C). Measured Mg/Ca values for B. marginata correlate well with temperature (Mg/Ca = 1.10 ± 0.10e0.045 ± 0.009T, R2=0.28, p
1 citations