radiolaria - Marum

Radiolaria 14 Bibliography - 1991
allowed us to the composition, trophic mode and biomass of the
spectrum of organisms that make up the winter plankton
assemblage.
Total nano- and microplankton biomass in the upper 100
meters of the water column ranged from 0.3 to 0.6 gC m -2 . The
biomass composition of plankton assemblages among the stations
was relatively uniform throughout the ice edge zone; however, the
autotrophic flagellates and dinoflagellates showed significantly
higher biomass at the ice edge or in open water relative to ice
covered stations. The heterotrophic biomass (protozooplankton)
exceeded the biomass of phytoplankton at most stations. Among the
autotrophic forms, dinoflagellates made up 38% of the biomass,
followed by other autotrophic flagellates (35%) and diatoms (27%).
The phytoplankton biomass was dominated by nanoplankton ( 20 µm dominated the
phytoplankton and standing stocks of Protozoa were lower, A. tonsa
obtained 2.3% of its daily carbon intake from protozoan prey. In the
subarctic North Pacific in June, where low phytoplankton standing
stocks are dominated by cells < 5 µm, N. phlumchrus CV obtained
11 - 18% of daily nutritional requirements from ciliate and
dinoflagellate Protozoa > 5 µm and was capable of clearing 11-16%
per day of the standing stock of Protozoa. In other protozoal taxa,
which were present but not included directly in our experiments, are
considered, N. plumchrus CV obtains potentially 28-59% of its daily
metabolic requirements from ingestion of protozoan prey.
Gorka, H. 1991. Les radiolaires du Turonien inférieur du
sondage de Leba IG 1 (Pologne). Cah. Micropal., 6/1, 39-45.
Lower Turonian Radiolarians (Polycystina) from the bore Leba IG
I (Poland, baltic region) are abundant and well preserved. Nine
species amongst spumellarians and six amongst nassellarians are
described.
Goto, H. & Ishiga, H. 1991. Study of late Ordovician
radiolarians from the Lachlan Fold Belt, Southeastern
Australia. Geol. Rep. Shimane Univ., 10, 57-62. (in
Japanese)
Gowing, M.M. & Garrison, D.L. 1991. Austral winter
distributions of large tintinnid and large sarcodinid
protozooplankton in the ice-edge zone of the Weddell/Sottia
seas. J. Marine Syst., 2, 131-141.
Seasonal distribution and abundance data for large sarcodinid
protozooplankton (Radiolaria, Foraminifera, Acantharia and the
heliozoan Sticholonche spp.) and larger tintinnid ciliates (e.g.,
Laackmaniella spp.) are necessary for evaluating their roles in food
webs and particle fluxes. As part of the Antarctic Marine Ecosystem
Research in the Ice Edge Zone (AMERIEZ) project, we sampled these
large ( ≥ 50 µm) protozooplankton in the winter ice edge zone of the
Scotia/Weddell Seas. Organisms alive at the time of capture were
counted in large volume (60 l) water samples from 5 paired depths
- 63 -
in the upper 2lO m from 17 stations. Relationships between
abundances and environmental factors in ice-covered, ice edge, and
open waters were assessed with correlation, cluster, and
multidimensional scaling analyses.
Mean abundances of large tintinnids were less than 3150 per
m 3 , and mean abundances of the individual sarcodine groups were
generally less than 1000 per m 3 . The most pronounced
distributional patterns were related to depth. In general, large
tintinnids were more abundant in the colder waters from 0-85 m, a
zone encompassed by the mixed layer and the euphotic zone.
Acantharians were more abundant in this upper zone only in icecovered
waters. Radiolaria (predominantly phaeodarians), and the
heliozoan Slicholonche spp. were more abundant from 115 to 210 m,
a zone of warmer, more saline water. Foraminiferan distributions
showed little pattern with depth. Results of the cluster analyses also
suggested that depth was the most significant effect determining
similarity among assemblages of large protozooplankton at the 17
stations. The few correlations between abundances of the groups
and chlorophyll a probably reflect relationships more complex than
grazing.
Abundances of large tintinnids were higher in surface waters
under the ice than at the ice edge or in open water. This could result
from their feeding on algal cells released from the base of the ice or
it may be a result of higher populations in the outflow of Weddell Sea
water. There were no consistent abundance patterns among large
sarcodines that could be related to ice cover. It is suggested that
the combination of low winter productivity, a dynamic environment,
and slower growth rates of these large protozoans may prevent them
from responding to local enhanced production with increased
abundances in the winter ice edge zone. Furthermore, although there
is enhanced productivity at the ice edge. this signal may not reach
the protozooplankton groups most abundant in the water layer below
the euphotic zone.
Guex, J. 1991. Biochronological Correlations. , Springer-
Verlag Berlin/Heidelberg/New York. , 250 p.
The object of this book is to explain how to create a synthesis
of complex biostratigraphic data, and how to extract from such a
synthesis a relative time scale based exclusively on the fossil
content of sedimentary rocks. Such a time scale can be used to
attribute relative ages to isolated fossil-bearing samples.
From a practical point of view, the method described in this
book will particularly interest paleontologists and geologists who
must construct zonations and establish correlations on the basis of
biostratigraphic data that are both plentiful and apparently
contradictory.
It is well known that the difficulties involved in constructing
biochronologic scales are largely due to the discontinuous nature of
the fossil record. We know that the relationships between the first
appearances (or disappearances) of different fossil species are
rarely constant in stratigraphic sections that are distant from each
other. It if often extremely difficult to discover datums or sets of
species that are useful in making significant biochronologic
correlations on a large scale.
The theoretical model explained here (known as the Unitary
Association Method) provides clear solutions to most of these
problems. That method is purely deterministic, as opposed to
statistical and probabilistic analytical techniques producing
"average" ranges. We demonstrate in Chapter 15 why most of these
techniques produce results which are usually not compatible with the
original biostratigraphic observations (i.e., the taxonomic contents
of the studied samples are not reproduced in the outputs).
The syntheses used here are in the form of a referential (i.e., a
system of chronologic reference); the chronologically significant
subdivisions of these referentials correspond roughly to the
Concurrent Range Zones and to the Oppel Zones of classical
stratigraphy. These zones are seen here as discrete (i.e.,
noncontiguous) units, isolated from each other by separation
intervals.
The operations required to construct such zonations are
elementary but not always simple. We will begin by analyzing the
fundamental properties of biochronologic referentials. This will
enable us to assess the validity of stratigraphic correlations based
on complex paleontological data. It will also help the reader master
the mathematics and algorithms that are indispensable for making
sense of the contradictory stratigraphic relationships so often
observed among species in different locations. The ideas presented
here were developed in a series of preliminary notes published
between 1977 and 1984. To avoid excessive self-citations, we will
mention in the text principally the ideas that are due to other
authors.
Two different computer programs making it possible to analyze
certain complex biostratigraphic data are used a number of time in
the present book. The oldest ones were written by Davaud and