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Active Projects

Determining the causes of ecological change
Palaeoecological data provide the most promising means of quantitatively assessing the past composition, structure and variability of benthic marine systems as well as how human activities have altered these systems... but they provide correlations rather than definitive tests of mechanisms driving changes. We are working to close the circle by testing these historical hypotheses using mechanistic experiments.
Composition of molluscan communities
Investigating, primarily soft-sediment, molluscan communities along the east Australian coast and wherever else our travels lead. Examining the diversity and abundance of living molluscs as an indicator of ecosystem health and function. We also use observational methods to understand the structure and dynamics of living molluscan communities.
Holocene geochronology
The fundamental pre-requisite for using fossils to provide quantitative baselines for conservation biology is being able to determine the age of individual fossils. We use a range of methods including calibrated Amino Acid Racemisation dating, the technique of choice for determining the age of Holocene fossils for conservation palaeoecology, taphonomy and time-averaging studies. Understanding the age of a fossil assemblage requires understanding two critical issues: 1. The age of the samples and 2. The amount of time recorded in the samples.
Temporal changes in benthic communities
Starting in 2004 I began collecting large diameters cores from GBR sediments. Molluscan shells from these cores are being used to examine the natural variability of these ecosystems as well as to identify potential changes in the modern molluscan communities associated with the colonisation of eastern Australia. This project has spawned a number of secondary projects aimed at addressing some of the assumptions underlying this project. Starting in 2013 we have expanded this approach to estuaries in New South Wales.
Quantitative taphonomy
This project focuses on a critical underlying assumption in any historical paleoecological research — do accumulating dead shells accurately record the living community?
Sedimentary records of organismal occurrence and abundance are only informative to the extent that the dead assemblage accurately reflects the living community. One approach is to compare the similarity of the living community to the dead shells accumulating in the sediment. Collecting these data to demonstrate the fidelity of the fossil record is time consuming research with a relatively long lead time, but it is essential to determine how post-mortum processes skew our perspective when reconstructing past communities. Another approach is through dating shells and modelling post-mortem processes assuming stochastically constant additions to the death assemblage.
CPL Databases
Large complex datasets require organization. I have built a variety of web-based databases to support various research projects throughout my career. Each of these sql databases are accessible via standard web browsers.
I allow public access to the systematic database that provides the taxonomic framework for my ecological data. This database has its roots in a database assembled during my doctoral dissertation but has grown over the years.
This is a secondary project supporting nearly all of the other lab projects.
Calcification Pathways in Marine Calcifiers
Laura Otter is a PhD Candidate under the supervision of Professor Dorrit Jacob and Dr. Matthew Kosnik in the Department of Earth and Planetary Sciences, Macquarie University in Sydney, Australia. She graduated with a Bachelor of Science (2012) and a Master of Science (2015) from the Gutenberg University in Germany, with majors in geochemistry, crystallography, and mineralogy. She is trained in microanalyses and biogeochemistry from her time as a research assistant at the Departments of Biogeochemistry and Climate Geochemistry, Max Planck Institute for Chemistry, Germany.

Her interdisciplinary research project merges the fields of structural marine biology and geochemistry and aims at a deeper understanding of the architectural building processes that dictate the growth in the shells of various marine calcifiers. For this purpose she conducts labelling experiments with different types of bivalves and benthic foraminifera that are maintained and monitored in aquaculture. Shells are studied with various analytical techniques to reveal the exact growth mechanisms. These studies will aid in the deeper understanding of calcified shells and their applicability for palaeoclimate reconstructions.

Anthropogenic impacts on estuarine molluscs from shell growth to community structure
This project aims to examine ecological changes in Sydney harbour over the last ~6000 years with emphasis in the last ~200 years since European colonization. Using sclerochronological techniques to determine differences in bio-mineralization rates and shell composition between live and dead molluscan assemblages, we are able to examine changes in the growth of bivalves living in this area. The results of this project will give an insight on the environmental history of this important Harbour and the historical and current impact of anthropogenic activities on the molluscan estuarine community.