18 documents found

Dissertation

Stress ecology in times of global change – single and combined effects...

Increasing atmospheric CO2 affects seawater pH and chemistry. This process, commonly known as ocean acidification (OA), has led to a decrease in oceanic seawater pH by 0.1 since the industrial revolution. Oceanic models show that mean pH may fall from the current 8.1 units to 7.8 and 7.5 by 2100 and...
Dissertation

Impact of elevated pCO2 on the ecophysiology of Mytilus edulis

Increasing atmospheric CO2 concentrations equilibrate with the surface water of the oceans and thereby increase seawater pCO2 and decrease [CO32-] and pH. This process of ocean acidification is expected to cause a drastic change of marine ecosystem composition and a decrease in calcification ability...
Dissertation

The suitability of Mytilus edulis as proxy archive and its response to...

Past climate changes can be used as indicators of future scenarios, however past climatic changes can not be directly observed. Therefore, the reconstruction of past abiotic conditions can approximated using chemical or isotopic proxies. These proxies can be measured in natural archives (e.g. bivalve...
Dissertation

Hypoxia tolerance of jumbo squids (Dosidicus gigas) in the Eastern Pacific...

Marine hypoxia has become one of the major concerns of the world, as oceanic dead zones continue expanding horizontally and vertically, a phenomenon primarily caused by global warming and anthropogenic eutrophication. As consequence, drastic changes in community structures, predator-prey relationships...
Dissertation

The ecological effect of CO2 on the brown algae Fucus serratus and its...

Carbon dioxide plays a central role in the functioning of organisms and ecosystems. For autotrophs, it is the substrate for photosynthesis while for heterotrophs it is a waste product of respiration. For two centuries Human activities, are responsible for an increase from 280 to 380 ╬╝atm of the atmospheric...
Dissertation

The bivalve Laternula elliptica: physiological and molecular response...

Increasing temperatures and glacier-disintegration at the Western Antarctic Peninsula (WAP) are presently altering environmental conditions in shallow coastal areas. Rising water temperatures, enhanced ice scouring impacts as well as increasing input of inorganic sediments from melt water runoff are...
Dissertation

Adaptation to contrasting habitats and heterozygosity-fitness-correlations...

Eelgrass Zostera marina is an ecosystem-engineering species in coastal soft sediment habitats that lives in widely diverging habitats. I aimed to detect divergent selection and habitat adaptation comparing 3 pairs of permanently submerged versus intertidal populations using genome scans, a genetic marker...
Dissertation

Mechanismen der CO2 Toleranz bei Seeigeln des Genus Strongylocentrotus

Die Zunahme des Kohlendioxids in der Atmosphäre aufgrund anthropogener CO2-Emissionen führt im Oberflächenwassers der Meere einerseits zu einem Abfall des pH Wertes und der Karbonationen-Konzentration und andererseits zu einem Anstieg des pCO2 Wertes und der Bikarbonat-Konzentration. Aktuellen Voraussagen...
Dissertation

Funktionelle Untersuchungen der Nebenwirkung des Antiepileptikums Carbamazepin...

In dieser Arbeit wurde die Wirkung des Antiepileptikums Carbamazepin (CBZ) auf den Wasser- und Elektrolythaushalt der Ratte untersucht. CBZ blockiert neuronale spannungsgesteuerte Na+-Kanäle, um die durch die neuronale Übererregbarkeit ausgelösten Krampfanfälle (Epilepsie) zu unterbrechen. In 48% der...
Dissertation

Impacts of ocean acidification and warming on Arctic calcifying key species...

Over the last two centuries human activities significantly changed the Earth system. Atmospheric CO2 concentrations were increased by ~25% in only 50 years (1965 to 2015) through combustion of fossil fuels and changes in land use. Consequences of these activities are a warming climate and the ‘acidification’...
Dissertation

Effects of Ocean Acidification on the Transcriptome of Larval Atlantic...

Ocean acidification, caused by the uptake of carbon dioxide (CO2) from the atmosphere, is impacting many marine organisms. This dissertation investigated the effects of direct exposure and parental acclimation to simulated ocean acidification on the larval stages of Atlantic cod (Gadus morhua, L.). For...
Dissertation

Bioenergetics of calcification in mytilid bivalves along the Baltic Sea...

The Baltic Sea salinity gradient provides an excellent system to investigate how seawater ion availability impacts calcification rates and the energetic costs of calcification. Additionally, the gradual changes in environmental conditions along this gradient also provide an excellent system to investigate...
Dissertation
Short version

The mechanisms of larval calcification in the mussel, Mytilus edulis

The mollusc shell is a composite biomineral consisting of calcium carbonate and an associated organic matrix. Biomineralisation in molluscs begins during early ontogenetic development, where larval calcification is characterized by rapid rates of mineral deposition. Despite...
Dissertation

Benthic interactions in a high CO2-world

The Baltic Sea is a physically diverse habitat with a generally low species diversity. The blue mussel Mytilus edulis is widely distributed in the benthic macrozoobenthos of the Western Baltic, the main predators of which are the common sea star Asterias rubens and the shore crab Carcinus maenas. Any...
Dissertation

Sea urchin membrane transport mechanisms for calcification and pH homeostasis

Larval sea urchins serve as a model organism for calcification and adult individuals are a keystone species in marine shelf ecosystems. Both life stages will presumably be affected by alterations of seawater pCO2 and the accompanying change in pH, [HCO3-] and [CO32-]. This change in seawater carbonate...
Dissertation

Mechanistic studies on the physiology of CO2 tolerance in cephalopods

Elevated environmental CO2 concentrations (hypercapnia) are a stressor that has lately received considerable attention: anthropogenic CO2 emissions are predicted to lead to a rise in surface ocean pCO2 from 0.04 kPa up to 0.08 - 0.14 kPa within this century. The increased hydration of CO2 changes seawater...
Dissertation

Immunostimulation in Early Life Stages of European Sea Bass (Dicentrarchus...

The reliable production of high quality juvenile fish is still hampered in marine aquaculture due to the enormous mortality in the larval stages, which is often caused by the outbreak of infectious diseases. Early life stages are extremely susceptible towards pathogens because they lack a mature immune...