Spatial dispersion of benthic Foraminifera in the abyssal central North Pacific 1

Abstract

Five 0.25‐m2 box cores (four open cores and one vegematic core subdivided in situ into 25 contiguous 10‐ × 10‐cm subcores) reveal that populations of benthic agglutinated Foraminifera in the central North Pacific are extremely abundant and diverse. As many as 120 species and 10,310 total fragments occur in a single open core, and the Foraminifera outnumber all metazoan taxa combined by at least an order of magnitude. Significant patchiness occurs on both the between‐core scale of kilometers and the within‐core scale of centimeters. Few species occurred in all cores and those that did were not abundant. Hierarchical classification and multiple discriminant analysis on the resultant subcore groups in the vegematic core suggest potential interactions between certain species of Foraminifera and such external variables as surface deposit feeders, subsurface deposit feeders, carnivores, filter feeders, biogenic surface structure, and manganese nodules. Multiple regressions of foraminiferan species against all the external variables substantiate the existence of patterns of association. Foraminifera are important components of the benthic fauna, acting, among other things, as predators and disturbance agents. It may well be that they have a more significant effect on the structure and dynamics of deep‐sea henthic communities than have any of the metazoan macrofaunal taxa that are the usual objects of deep‐sea studies.

Response of the benthic foraminiferal community to a simulated short-term phytodetritus pulse in the abyssal North Pacific

“…Observations on population densities in the central North Pacific (Hessler & Jumars 1974, Bernstein et al 1978, Snider et al 1984 and in the Northeast Pacific at Stn M (Drazen et al 1998) have shown the numerical importance of benthic foraminifera among the sediment-inhabiting fauna in this region, indicating their important contribution to carbon cycling here. Especially monothalamous soft-walled foraminifera are important components of deep-sea sediments (Gooday 1994), in particular in oligotrophic areas and below the carbonate compensation depth with an assumed diet of refractory organic material and bacteria (Gooday et al 2008).…”

Influence of seasonally deposited phytodetritus on benthic foraminiferal populations in the bathyal northeast Atlantic. the species response

“…There were also some significant differences in the abundance and variance of species in the total populations (Tables 7 to 9). Patchy distributions of benthic foraminiferal populations are well documented in both shallow water (Buzas 1968, 1970, Lee et al 1969, Matera & Lee 1972, Bernhard 1987, Hohenegger et al 1989) and the deep-sea (Bernstein et al 1978, Bernstein & Meador 1979, Kaminski 1985. Such spatial heterogeneity may have contributed to at least some of the differences observed between the April and July assemblages.…”

Cenozoic deep-water agglutinated foraminifera in the North Atlantic

“…Habitat partitioning --A number of studies have suggested microhabitat partitioning as an important factor for the maintenance of diversity in deep sea benthic communities (Jumars, 1975;Bernstein et al, 1978). Under equilibrium conditions, species which do not share the same microhabitat do not compete with one another, and the diversity of the community can be maintained at high levels.…”