Table Of ContentProcesses of calcification and sedimentation
of the tropical marine green macro-alga genus Halimeda
and effects of ocean acidification
on its calcareous microstructure
Thesis for the completion of a Dr. rer. nat.
Department of Geosciences (FB5)
University of Bremen
André Wizemann
Geoecology and Carbonate Sedimentology
Group leader and supervisor: Prof. Dr. Hildegard Westphal
Second referee: Prof. Dr. Helmut Willems
Bremen, June 2015 / colloquium 20.07.2015
Name : André Wizemann Datum: 01.06.2015
Anschrift : Kulenkampffallee 77, 28213 Bremen
Erklärung
_____________________________________________________________________
Hiermit versichere ich, dass ich
(1) die Arbeit ohne unerlaubte fremde Hilfe angefertigt habe,
(2) keine anderen als die von mir angegebenen Quellen und
Hilfsmittel benutzt habe,
(3) die den benutzten Werken wörtlich oder inhaltlich
entnommenen Stellen als solche kenntlich gemacht habe und
(4) weder diese noch eine ähnliche Arbeit an einer anderen
Abteilung oder Hochschule im Rahmen eines
Prüfungsverfahrens vorgelegt, veröffentlicht oder zur
Veröffentlichung vorgelegt habe.
Bremen, den 01.06.2015
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(Unterschrift)
Table of Contents
Acknowledgments ........................................................................................................ I(cid:1)
Abstract ...................................................................................................................... III(cid:1)
Zusammenfassung ...................................................................................................... V(cid:1)
Conference contributions ........................................................................................ VII(cid:1)
Overview of publications (chapters in this thesis) ................................................... X(cid:1)
1. Introduction .............................................................................................................. 1(cid:1)
1.1 Calcareous green macro-algae genus Halimeda .................................................... 1(cid:1)
1.1.1 Halimeda opuntia (L.) lineage Opuntia ....................................................................... 1(cid:1)
1.1.2 The morphological microstructure of the Halimeda segment ...................................... 3(cid:1)
1.1.3 The process of calcification in the macro-alga genus Halimeda .................................. 4(cid:1)
1.1.4 The development of the skeletal microstructure of the Halimeda segment ................. 4(cid:1)
1.1.5 External carbonic anhydrase activity (eCA) within the IUS ........................................ 6(cid:1)
1.2 The process of ocean acidification: present, future and past ................................. 6(cid:1)
1.2.1 The effect of ocean acidification on marine calcifiers ................................................. 8(cid:1)
1.2.2 Effects of ocean acidification on the calcification of Halimeda .................................. 9(cid:1)
1.3 Halimeda sediments .............................................................................................. 9(cid:1)
1.3.1 Species-specific sedimentary Halimeda segments and their early preservation
potential ........................................................................................................................... 11(cid:1)
2. Materials and methods .......................................................................................... 13(cid:1)
2.1 Laboratory studies ............................................................................................... 13(cid:1)
2.1.1 Setup of seawater aquaria and laboratory conditions ................................................. 13(cid:1)
2.1.1.1 Calcification experiment setup ............................................................................................13(cid:1)
2.1.1.2 Elevated pCO experiment in mesocosms ...........................................................................13(cid:1)
2
2.1.2 Water parameter control and measurements (both experiments) ............................... 14(cid:1)
2.1.3 Laboratory sample collection and preparation for SEM analyses .............................. 14(cid:1)
2.1.3.1 Stub samples ........................................................................................................................15(cid:1)
2.1.3.2 Thin-sections .......................................................................................................................15(cid:1)
2.2 Sedimentary studies ............................................................................................. 15(cid:1)
2.2.1 Field sampling and sediment screening ...................................................................... 15(cid:1)
2.2.2 Field sample preparation for SEM analysis ............................................................... 15(cid:1)
3. Manuscript I : A new model for the calcification of the green macro-alga
Halimeda opuntia (Lamouroux) (2014) Wizemann A, Meyer FW, Westphal H .. 17(cid:1)
3.1 Extended discussion on the calcification of the green macro-alga genus
Halimeda .................................................................................................................. 32(cid:1)
3.1.1 Primary calcification .................................................................................................. 32(cid:1)
3.1.1.1 The role of external carbonic anhydrase activity (eCA) in the calcification of macro-algae
genus Halimeda ............................................................................................................................33(cid:1)
3.1.1.2 Crystal growth initiation at acidic macro-molecules on the cell wall .................................35(cid:1)
3.1.2 Micro-anhedral carbonate (MAC) formation ............................................................. 36(cid:1)
3.1.2.1 Segments of different Halimeda species and their density in MAC ...................................38(cid:1)
3.1.3 Secondary calcification .............................................................................................. 40(cid:1)
3.1.4 Ca2+ ion fluxes in the Halimeda skeleton ................................................................... 41(cid:1)
3.1.5 Seawater metal ion ratio alteration (m Mg / Ca ratio); Further evidence for biotic
calcification in macro-algae genus Halimeda .................................................................. 41(cid:1)
4. Manuscript II : Ocean acidification alters the calcareous microstructure of the
green macro-alga Halimeda opuntia (2015) Wizemann A, Meyer FW, Hofmann
LC, Wild C, Westphal H ........................................................................................... 43(cid:1)
4.1 Extended discussion on the effect of elevated seawater pCO on the skeletal
2
features of the green macro-alga genus Halimeda ................................................... 62(cid:1)
4.1.1 Primary calcification and elevated seawater pCO .................................................... 62(cid:1)
2
4.1.2 Primary cementation and elevated seawater pCO ..................................................... 63(cid:1)
2
4.1.3 Secondary calcification and elevated seawater pCO ................................................ 64(cid:1)
2
4.2 A theoretical model for the process of calcification in macro-algae of the genus
Halimeda and the effects of ocean acidification ...................................................... 65(cid:1)
4.2.1 Daytime processes under ambient seawater carbon chemistry .................................. 65(cid:1)
4.2.2 Nighttime processes under ambient seawater carbon chemistry ................................ 66(cid:1)
4.2.3 Daytime processes under elevated seawater pCO ..................................................... 66(cid:1)
2
4.2.4 Nighttime processes under elevated seawater pCO .................................................. 67(cid:1)
2
5. Manuscript III : Microstructural analyses of sedimentary Halimeda segments
from the Spermonde Archipelago (SW Sulawesi, Indonesia): a new indicator for
sediment transport in tropical reef islands? (2015) Wizemann A, Mann T,
Klicpera A, Westphal H ............................................................................................ 71(cid:1)
5.1 Extended discussion on the carbonate sediment formation of the green macro-
alga genus Halimeda ................................................................................................ 90(cid:1)
5.1.1 Halimeda segments from sediments worldwide ........................................................ 91(cid:1)
5.1.2 Origin and alteration of Halimeda segments in the sediment .................................... 92(cid:1)
5.1.2.1 Cementation and dissolution as in-situ processes ...............................................................93(cid:1)
5.1.2.2 Physical surface abrasion during sediment transport ..........................................................94(cid:1)
5.1.2.3 Micro-bioerosion .................................................................................................................94(cid:1)
5.1.3 The potential of Halimeda segments as proxies for sediment transport .................... 95(cid:1)
6. Conclusions and scientific outlook ....................................................................... 97(cid:1)
6.1 Insights into the process of calcification of macro-algae genus Halimeda ......... 97(cid:1)
6.1.1 The role of alkaline phosphatase in CaCO biomineralization .................................. 98(cid:1)
3
6.1.2. High resolution structural analyses on the composition of the CaCO skeleton ....... 99(cid:1)
3
6.2 The alteration of the internal microstructure and the process of calcification
under elevated seawater pCO ............................................................................... 100(cid:1)
2
6.2.1 Analyses to investigate microstructural alteration under elevated seawater pCO .. 100(cid:1)
2
6.2.2 Expression of extracellular and cell wall components under elevated pCO ........... 101(cid:1)
2
6.2.3 Consequences of elevated seawater pCO for the ecology of Halimeda ................. 101(cid:1)
2
6.3 Halimeda segment alteration in sedimentary processes and their potential use as
sediment tracers ..................................................................................................... 102(cid:1)
6.3.1 Anthropogenic influences on carbonate sediment production of Halimeda ............ 103(cid:1)
7. References ............................................................................................................. 105(cid:1)
X. Appendix .............................................................................................................. 123(cid:1)
X.I Abbreviations .................................................................................................... 123(cid:1)
X.II Plates of thin-sections from Halimeda segments from surface sediment
samples. .................................................................................................................. 125(cid:1)
Acknowledgments
I want to thank my supervisor Prof. Dr. Hildegard Westphal for the opportunity to
conduct research on this fascinating subject at the Leibniz-Center for Tropical Marine
Ecology (ZMT), the kind atmosphere in discussions and her constructive and helpful
comments on the thesis and the manuscripts. In the same way, I also thank my PhD
colleague Fritz Meyer as I would not have been able to conduct the laboratory
research without his help and with whom I had fruitful discussions that led to
interesting conceptual ideas. A great part of work would not have been possible
without the tremendous effort of ZMT technician Sebastian Flotow in preparing
petrographic thin-sections of such tiny and fragile biological samples and his
continuous aim to advance the techniques. Further, I want to thank all my colleagues
of the working group “Carbonate Sedimentology” at ZMT. André Klicpera with
whom I shared the office for a long time and later on also Thomas Mann, Peter Müller
and Marleen Stuhr. The pleasant atmosphere in the office led to extensive discussions
for which I am sorry if I distracted you from your work way too often with some of
my “crazy” ideas. I also have to thank Natalia Herrán Navarro, Gita Roshni Narayan,
Claire Reymond, and other (co-)members of our group that however here remain
unnamed, nevertheless shall feel addressed. Of course, special credits go to Nereo
Preto for establishing the “espresso round” during his research stays at ZMT and I
think this little custom fits best the nice atmosphere of our working group ;) In the
end, Julien Michel shall not be forgotten and I remember with joy and thank him for
the great dinners we all shared together at his former place in Bremen. With our
group’s team spirit, of everybody supporting each another, it was a pleasant working
experience that I do not want to miss.
I
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Description:Veröffentlichung vorgelegt habe. Bremen, den . 1.3.1 Species-specific sedimentary Halimeda segments and their early preservation potential .
