Quantitative paleoenvironmental studies using freshwater ostracods in northeast Germany [Elektronische Ressource] / Finn Andreas Viehberg, geb. Heinrichs

Quantitative paleoenvironmental studies using freshwater ostracods in northeast Germany Inauguraldissertation zur Erlangung des akademischen Grades doctor rerum naturalium (Dr. rer. nat.) an der Mathematisch- Naturwissenschaftlichen Fakultät der ERNST - MORITZ - ARNDT - UNIVERSITÄT GREIFSWALD vorgelegt von Finn Andreas Viehberg, geb. Heinrichs geboren am 12.01.1975 in Braunschweig Dersekow, am 25. April 2005 Dekan: 1. Gutachter/in: 2. Gutachter/in: Tag der Promotion: Ostracoda Muschelkrebse (German) Seed-Shrimps (English) Musselkräftors (Swedish)Mosselkreeftjes (Dutch) Ma łżoraczki (Polish) Рак у шковые (Russian) F. A. Viehberg: Quantitative paleoenvironmental studies using freshwater ostracods in northeast Germany Table of contents 1. Introduction........................................................................................................................1 1.1. The use of ostracods in quantitative paleoenvironmental studies ....................................... 3 1.2. Main objectives...................................................................................................................... 6 2. Study area..........................................................................................................................7 3. Historical review of ostracod records in Mecklenburg-Vorpommern ...................
Publié le : samedi 1 janvier 2005
Lecture(s) : 64
Source : UB-ED.UB.UNI-GREIFSWALD.DE/OPUS/VOLLTEXTE/2006/73/PDF/VIEHBERG.PDF
Nombre de pages : 144
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Quantitative paleoenvironmental studies
using freshwater ostracods
in northeast Germany







Inauguraldissertation

zur Erlangung des akademischen Grades
doctor rerum naturalium (Dr. rer. nat.)
an der Mathematisch- Naturwissenschaftlichen Fakultät der
ERNST - MORITZ - ARNDT - UNIVERSITÄT GREIFSWALD


vorgelegt von
Finn Andreas Viehberg,
geb. Heinrichs
geboren am 12.01.1975 in Braunschweig
Dersekow, am 25. April 2005















Dekan:

1. Gutachter/in:
2. Gutachter/in:


Tag der Promotion:


















Ostracoda

Muschelkrebse (German)
Seed-Shrimps (English)
Musselkräftors (Swedish)
Mosselkreeftjes (Dutch)
Ma łżoraczki (Polish)
Рак у шковые (Russian)


F. A. Viehberg: Quantitative paleoenvironmental studies using freshwater ostracods in northeast Germany

Table of contents
1. Introduction........................................................................................................................1
1.1. The use of ostracods in quantitative paleoenvironmental studies ....................................... 3
1.2. Main objectives...................................................................................................................... 6
2. Study area..........................................................................................................................7
3. Historical review of ostracod records in Mecklenburg-Vorpommern ........................11
3.1. Checklist of recent and quaternary ostracods (Crustacea) from freshwater, brackish and
marine environments in Mecklenburg-Vorpommern, NE Germany.......................................... 11
4. Material and Methods......................................................................................................39
4.1. A new and easy method for qualitative sampling of meiobenthos-communities ............... 40
5. Paleoenvironmental studies...........................................................................................43
5.1. Paleolimnological study based on ostracods (Crustacea) in late-glacial and Holocene
deposits of Lake Krakower See (Mecklenburg-Vorpommern, NE Germany)........................... 43
5.2. Lateglacial and Holocene ostracod assemblage succession in the southern Baltic Sea
(Germany) .................................................................................................................................. 51
6. Training set......................................................................................................................72
6.1. Freshwater ostracod assemblages and their relationship to environmental variables in
waters from northeast Germany ................................................................................................ 72
7. Summary..........................................................................................................................94
8. Zusammenfassung..........................................................................................................95
9. References.......................................................................................................................96
Appendix ...........................................................................................................................109
A Species...........................................................................................................................109
A 1. Darwinuloidea Brady & Norman, 1889 ........................................................................... 109
A 2. Cypridoidea Baird, 1845.................................................................................................. 109
A 3. Cytheroidea Baird, 1850 ................................................................................................. 113
B Data ...........................................................................................................................115
B 1. Study sites (training set) ................................................................................................. 115
B 2. Training set...................................................................................................................... 117
B 3. Training set (lakes).......................................................................................................... 128
1. Introduction
1. Introduction

Ostracods (Crustacea, Ostracoda) are small bivalved aquatic crustaceans. They are one of
the most diverse groups in the Arthropoda with an excellent fossil record throughout the
entire Phanerozoic (Hinz-Schallreuter & Schallreuter 1999). Their carapace is composed of
two valves, which are hinged dorsally. The single valves are segregated of low-magnesium
(Mg) calcite, which are able to preserve in sediments with non-acidic porewaters. They
inhabit marine, brackish-, and freshwater environments and some species are also described
from semi-terrestrial habitats, inland saline, hot mineral springs, groundwaters, and other
extreme aquatic habitats.
The freshwater ostracods in the present study area are typically 0.5 to 1.5 mm long,
however, some interstitial forms are only 0.2 mm in size, while other species attain 3 mm.
They undergo a postembryonic ontogeny of eight larval stages, each composing a new
carapace, which is discarded during the next moult process. The duration of the whole
lifecycle is species and temperature dependant and lasts between several weeks to a year.
Frequently, it goes along with a stenochrone seasonal phenology of the species.
The present work focuses on extant and subfossil freshwater ostracods. The collected
species of the present work belong to the three podocopid superfamilies, Darwinuloidea
*Brady & Norman, 1889, Cypridoidea Baird, 1845, and Cytheroidea Baird, 1850. Their
representatives are sediment dwellers or fairly good swimmers of the benthos (Figure 1).
They are mainly scavengers or feed on organic detritus, microbial mats, algae and/or aquatic
fungi. Furthermore, some species live in specialized biocoenoses (e.g., pleuston, stygon)
and are well adapted to it.
But despite their potential to colonize a large range of water types, ostracods occur less
frequently in subneutral waters. Moreover, they react sensitive to various other ecological
variables. It is known that salinity, temperature, oxygen saturation, and chemical composition
of the host water influences the occurrence of ostracod species. The composition of ostracod
assemblages are equally influenced by habitat type and stability, water depth and energy
level. The tolerances and especially the preferences of each species are utilized in
environmental studies dealing with ostracods. So, they were successfully applied as indicator
organisms in water and sediment quality assessment (e.g., Namiotko et al. 1993, Mezquita et
al. 1999; Chial et al. 2003).
The knowledge can also be used to reconstruct paleoenvironmental conditions, because
ostracod valves are commonly preserved in Quaternary sediments. It is demonstrated in
various studies that ostracods are valuable indicators for describing changes in lakes
paleohydrology (e.g., Colman et al. 1994, Mourguiart et al. 1998) or trophic status (e.g.,
Scharf 1998). Furthermore, environmental variables are reconstructed, such as temperature
(e.g., Colman et al. 1990; Forester 1991), salinity (e.g., Gell et al. 1994; Boomer et al. 1996),
or ion-composition (e.g., Forester 1991; Smith et al. 1992).
The studies were able to describe distinct changes in the investigated basins, where the
ostracod record mostly co-varies with lithology and other proxy results. Anyway a
quantification of the reconstructed variables is often missing.

* In paleontological literature it is common to use the ending '-acea' for superfamily ranking. The suffix
'-oidea' is used here, according to Article 29 of the International Code of Zoological Nomenclature
(fourth edition, 1999)
-1- 1. Introduction
Geochemical analyses of subfossil ostracod valves focus on trace-element ratio (Sr/Ca and
18 13Mg/Ca) and stable isotope composition ( O and C). Signals in the geochemical record
reflect paleoenvironmental alterations on a more objective level (Holmes & Chivas 2002;
Schwalb 2003) and in some studies it is also possible to quantify the results (e.g., von
Grafenstein et al. 1992). But the knowledge of the ecology of living ostracods is essential to
interpret the geochemical results of the past (De Deckker 2002).
It is the general scope of the present work to refine the indicator ability of freshwater
ostracods and to use their described potential for aspects in Lateglacial and Holocene
paleolimnological research in northeast Germany. An evaluation of the available regional
data from previous paleontological and ecological studies revealed that this group was
already used to some extent in the study area, started already in the middle of the
th19 century (i.e., Ehrenberg 1842). However, ecological data of freshwater ostracods are still
rare. Similar limited effort has been made to use this group consequently as
paleoenvironmental indicator in Lateglacial or Holocene deposits according to the published
data (Frenzel & Viehberg 2002).
This thesis subsequently demonstrates a quantitative paleoecological approach that uses
freshwater ostracods in lacustrine and nearshore deposits in the study area for the first time.
Additionally, modern ecological data are analyzed to refine the ability of quantitative
paleoenvironmental reconstructions.


Figure 1. Life-style of freshwater ostracods. 1: pleustobiont (e.g., Notodromas), 2-5: benthic,
2-3: swimmer (e.g., Cypria, Cyclocypris), 4-5: dweller (e.g., Candona, Darwinula), 6: stygobiont
(e.g., Nannocandona)
-2- 1. Introduction
1.1. The use of ostracods in quantitative paleoenvironmental studies

Subfossil remains which are identified and counted within a sample are basically quoted as
quantitative data. To make them not only relatively but directly comparable to other
assemblages, the given sample volume or dry weight has to be known.
Although, ostracod assemblages are usually studied quantitatively, the reconstructions may
be of qualitative nature and rather describe the environmental variables. Describing past
conditions is feasible and reliable to the given circumstances as long as the environmental
changes do not have to be quantified. However, quantitative reconstructions of past
environments are needed for climate models. Ostracod analysis has the potential to fulfill this
requirement, but only few methods are available and often regionally restricted.
There are three main approaches to reconstruct past environments quantitatively from
subfossil assemblages: Indicator species approach, assemblage approach, and multivariate
transfer function approach (Birks 2003).
But as a general requirement of all above mentioned methods, the ecological tolerances
have to be known of the investigated subfossil species. Additionally, the methodological
uniformitarianism has to be assumed when ecological data of extant species are linked to its
subfossil counterparts (Rymer 1978).
References which contribute to the ecological requirements of single ostracod species are
widely distributed throughout the literature and of different quality. Whole year surveys are
preferable, as they reflect the ecological affinities of the species in seasonal periodicity. (e.g.,
Nüchterlein 1969; Hiller 1972; Usskilat 1975; Vesper 1975; Scharf 1976; Mallwitz 1984).
In the following, the four different approaches in quantitative studies are outlined using
freshwater ostracods.
Descriptive approach
The descriptive approach is the most common analysis of ostracod remains. It considers the
subfossil assemblage as a whole and the proportion of its different taxa. The dominant
species are supposed to have lived in their ecological optima and therefore reflect the
environmental conditions best. The subdominant species are used to refine the past habitat.
More advanced descriptive approaches deal with ratios of dominant species (Forester et al.
1994), where the main species describe different conditions/situations (e.g., 'increased
salinity', 'shallow water', 'deep water'). Thus, shifting ratios visualize clearly changes in the
paleoenvironmental evolution of the investigated basin.
Indicator species approach
A quantitative reconstruction of single environmental parameters is possible due to an
indicator species approach. It requires information about what environmental factors
influence the distribution and abundance of the concerned species today. The commonest
means of obtaining such information is to compare present-day distributions of species with
selected climatic variables of potential ecological and physiological significance, such as
temperature. If the geographical trend of an ecoclimatic variable covaries with the species
distribution, a cause-and-effect relationship is often assumed. For example, Tonnacypris
glacialis (Sars, 1890) is widely distributed in Arctic fresh waters and described as an indicator
of mean summer temperatures of 6 °C (Griffiths et al. 1998). This information can be inferred
-3- 1. Introduction
to the European Pleistocene, where T. glacialis is found frequently (e.g., Diebel & Pietrzeniuk
1978, Krstic 1993).
Assemblage approach
An assemblage approach tries to put the descriptive approach on a more quantitative basis.
It is often referred to as modern analogue technique (MAT) in pollen literature (e.g.,
Overpeck et al. 1985, Cheddadi et al. 1998). The theoretical faunal assemblage (TFA)
method follows a similar statistical method to compare numerically the subfossil freshwater
ostracod assemblage with modern assemblages by dissimilarity measure (Delorme et al.
1977; Delorme 1989). The comparison is restricted to the net geographical distribution,
where the modern fauna occur in their natural range. This technique is based on faunistic,
physicochemical and climate information of over 6700 sites, mostly in the Canadian Interior
Plains sampled by Delorme (1965, 1970a-d, 1971, 1978). But although it was applied to
various paleoenvironmental reconstructions (Karrow et al. 1995; Delorme 1996; Porter et al.
1999; Curry & Delorme 2003) and led to very accurate quantitative results, the method is
geographically restricted and until now not published in total (Smith et al. 2003). In general,
assemblage approaches are limited in their handling as the modern datasets have to cover a
wide environmental and geographical range and there are no reliable error estimates for the
reconstructed values (Birks 1995). Additionally, methodological problems arises when no
modern assemblages are similar to the subfossil assemblage or several modern analogues
matches but differ widely in their climate origin (Huntley 1996).
Multivariate transfer function approach
The following approach models numerically the relationship between modern species
assemblages and the associated modern environmental variables. The resulting transfer
function is used to infer the past environmental variables from the subfossil species
assemblage, which is comprised of species used in the particular model (Figure 2). Like in
the previous methods the reconstruction accuracy depend on the quality of the original
ecological dataset (training set).
To assure a strong relationship between the taxa and the concerned environmental
variables, multivariate statistic such as ordination methods are applied. Environmental
parameters which are tested to be systematically related to the species fit the requirements
for the final model.
It was first used to estimate the summer and winter sea surface temperature and salinity in
the Pleistocene of the Caribbean Sea using foraminifers (Imbrie & Kipp 1971). Later, the
numerical procedure was adopted for freshwater environments (Birks 1995). The relatively
robust model based on the weighted averaging (WA) regression and calibration was already
used for several organism groups. Transfer functions are developed for diatoms (e.g., Pienitz
& Smol 1993; Pienitz et al. 1995; Dissolved organic carbon, dissolved inorganic carbon),
chironomids (e.g., Olander et al. 1999; water temperature), cladocerans (e.g., Lotter et al.
1997; water depth, temperature) and freshwater ostracods (e.g., Curry 1999; Mourguiart &
Carbonel 1994; Mourguiart et al. 1998; Mourguiart & Montenegro 2002; water depth, total
dissolved solids, dissolved bicarbonate, and calcium ion).
Similar to the above mentioned methods the modern training set has to include preferably as
much modern species as expected subfossil counterparts. WA-models are more complex
-4- 1. Introduction
indicator species approaches, but where several taxa are used in the transfer function.
Estimates of the 'optima' of the concerned parameter are derived from the modern training
set rather than from modern autecological observations. Another advantage of this method is
that the accuracy of the inferred environmental variable can be tested (e.g., Monte Carlo
permutation test) by error estimates (Birks 1998).
Transfer functions may be regionally restricted as the accounted species do not occur in the
modern training set. In general, the training set should consist of a wide geographical range
with a likely range of past environmental variables. Furthermore, it should have a consistent
taxonomy and nomenclature and sampled from the same sedimentary environment as the
collected subfossil material (e.g., lakes) (Birks 2003).







modern ostracods



training set
(ecological dataset)

subfossil ostracods

















Figure 2. Outline of the transfer function approach to paleoenvironmental reconstructions
(modified from Juggins, unpubl.)
-5- 1. Introduction
1.2. Main objectives

The present thesis is defined as a initial paleolimnological study. It follows two independent
approaches using freshwater ostracods. One investigates the regional subfossil fauna
(Chapter 5.1. & 5.2.), while the other focuses on modern species assemblages (Chapter
6.1.). Both have in common to utilize and strengthen the group for future paleoenvironmental
investigations.

Lateglacial and Holocene ostracod fauna
Investigations on Lateglacial and Holocene freshwater ostracods in northeast Germany are
rare and their records fragmentary. Nonetheless, the group occur frequently in lacustrine
sediments throughout the area. So it is reasonable to use this group for paleoenvironmental
reconstruction in regional investigations. Despite the paleoecological potential, ostracods
have received less attention from Quaternary researchers in the study area than other
microfossilgroups such as pollen (e.g., Kliewe & Lange 1968; Janke 1996; de Klerk 2002) or
diatoms (e.g., Dreßler et al. 2002; Hübener & Dörfler 2004).
It is an objective of the present work to analyze the subfossil ostracod record of two
exemplary coring sites by quantitative means, to maximize their indicator ability, and
eventually demonstrate the potential of this zoological indicator for future investigations.

Modern ecological data set
An understanding of a species’ ecology is vitally important to any explanation of its
occurrence, behavior, and reproductive biology and a sound knowledge of modern ecological
affinities is essential for any paleoecological inquiry. Recently, Meisch (2000) compiled
ecological data of all known species from West and Central Europe, but he and other authors
(e.g., Holmes 2003) regret that only limited quantitative ecological data are available. As a
consequence, most paleoenvironmental reconstructions based on freshwater ostracods fail
to quantify their results.
To contribute to this issue, it is one objective of the present work to build a modern ecological
dataset (training set) and develop a quantitative transfer function for paleoenvironmental
variables. Previously established transfer functions using freshwater ostracods are applied
as powerful paleoecological tools, but unfortunately not regionally applicable. The present
model will be the first which is usable in the study area for future paleoenvironmental
investigations.
-6-

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