My research expertise focuses on tropical coral reef ecosystems and how they response to changing sea levels and tropical climate variability, over a range of temporal and spatial scales. Particular areas of research interest relate to climate change and human impacts on coral reefs, and palaeoclimate reconstructions for the recent past (100-100kyr).
For most of my career, I have worked on Indian Ocean coral and sediment records. This work is motivated by the need to produce reliable, long-term basely ne data of sea surface temperature, ocean currents and the hydrological cycle over the tropical/subtropical oceans and how they shape patterns of biodiversity in our oceans and adjacent coasts.
Major research interests:
- Geochemical proxies in coral carbonate
- Indian Ocean climate change
- Global climate teleconnections
- Human impact on coral reefs
- Coral Reefs and Climate Change
Dr. Zinke leitet das Korallen-Labor. Im Korallen-Labor der FU Berlin Palaeontologie werden Korallenkerne aus den Tropen und dem Mittelmeer zur geochemischen Analysen gebohrt und aufbereitet. Wir benutzen ein Unterwasserbohrsystem angetrieben durch Druckluft aus Tauchflaschen welches eine 30cm lange und ca. 4 cm im Durchmesser Bohrkrone mit Diamanten antreibt. Wir benutzen bis zu 1m lange Metallstangen um bis zu 4.5m lange Kerne aus massiven Korallen zu bohren. Die Aufbereitung der Kerne beinhaltet das Sägen der Kerne zu 0.7mm dünnen Scheiben, deren chemische Reinigung um organische Kontaminationen zu entfernen, sowie die hochauflösende (0.5-2mm) Beprobung der Korallen mit einem speziell gebauten Zahnarztbohrer. Das gewonnene Pulver aus den Korallen wird spaeter am Leibniz Institut des Museums fuer Naturkunde (Prof. Struck) auf seine isotopische Zusammensetzung untersucht. Zudem werden am selben Pulver noch die Spurenelemente untersucht welche Rückschlüsse auf Umweltveränderungen ermöglichen sowie die Rekonstruktion der Oberflaechentemperaturen, des Salzgehaltes der tropischen Ozeane und klimatologischer Veränderungen. Im Korallen-Labor werden ausserdem Röntgenbilder und UV-Fluorescenz Bilder von Korallenkernen sclerochronologisch bearbeitet um die jährlichen Wachtumsbaender auszumessen und zudem noch die Dichte des Skelettes und die Kalzifikationsrate zu bestimmen. Letzteres spielt eine grosse Rolle um die Auswirkungen der steigenden Meerestemperaturen und des sinkenden pH Gehaltes im Meer auf das Wachstum der Korallen zu ermitteln. Die UV Bilder sind geeignet um organische Einschlüsse im Skelett der Korallen sichtbar zu machen und somit Hinweise auf sedimentären Flusseintrag durch anthropogene Entwaldung und Bodenerosion zu erlangen. Die Korallen gelten als Schlüsselarchiv der marinen Palaeoklimatologie in den Tropen. Korallen eignen sich auch um das Klima des Holozaens und anderer Warmzeiten in den vergangenen 30 Millionen Jahren zu untersuchen. Zudem sind Korallen auch Baumaterialien in archäologischen Fundorten wodurch eine Verknüpfung von Klimavariabilität und menschlichem Handeln möglich sein kann.
Developing a 200 year index of Indo-Pacific climate connectivity
Lack of long instrumental climate records from the eastern Indian Ocean and Indo-Pacific warm pool, the heat engine of the global climate system and an essential player in Austral-Asian rainfall/drought cycles, is the main problem for reducing uncertainties in model-based climate change process studies and projections for Australia and to successfully plan for the future. This project will fill this key knowledge gap in long-term marine climate variability in the south-eastern Indian Ocean off the coast of Western Australia (WA) on the western extension of the globally important Indo-Pacific warm water pool. It will use state-of-the-art analytical approaches to obtain unique paleoclimatological reconstructions from massive corals dating back to ~1800 AD. These new datasets will improve our understanding of shifts in the climate system that are often caused by relatively small-magnitude ocean temperature changes. These climate shifts can persist for many decades and strongly affect the vulnerability and resilience of the unique marine and terrestrial socio-ecological systems along the western coast of Australia and the wider Indo-Pacific.
This project is a collaboration with Curtin University and the Australian Institute of Marine Science.
The role of the Western Pacific sea surface temperature gradient in global hydrology
The Maritime Continent (MC) is the hydrological power house of the planet being collocated within the Indo-Pacific Warm Pool, where sea surface temperatures (SST) exceed 28°C associated with strong convective rainfall year-round. The Maritime Continent includes the archipelagos of Indonesia, New Guinea, and Malaysia, and the surrounding shallow seas. As such the MC is the crucial part of the global hydrological variability through its influence on the Indo-Pacific Walker circulation. New research has shown that the temperature gradient between the westernmost Pacific and the Nino4 region of ENSO variability (hereafter West Pacific Gradient= WPG) plays a pivotal role in the global climate teleconnections (Hoell and Funk, 2103). This project will fill this key knowledge gap in long-term marine climate variability from the globally important Indo-Pacific warm water pool. It will use publically available paleoclimatological reconstructions from massive corals dating back to ~1800 AD. These datasets will improve our understanding of shifts in the climate system that are often caused by relatively small-magnitude ocean temperature changes.
This project is a collaboration with Macquarie University Sydney, Australia.
A geospatial assessment, long term monitoring and environmental reconstruction of marine habitats within the Miri-Sibuti National Park, Borneo, Malaysia
The tropical marine fauna diversity in South East Asia, particularly that off Sarawak East Malaysia has been described as ‘greater than any other on earth’ and is considered one of the world’s biodiversity “hot-spots”. The coastline of the largest state Sarawak which extends approximately 1035 km, lies within the Indo-Malay-Philippine archipelago, and is located on the northern side of the Island of Borneo. This area of coastal reefs sustains a rich assemblage of marine life including fish, corals, molluscs, crustaceans and marine mammals. Our current knowledge of marine habitats within the marine park comes from a small number of Reef Check sites that have been monitored since 2009. However, long-term data are seriously lacking.
Changing river runoff into marine catchments is recorded by giant corals that incorporate soil-derived humic acids in their carbonate skeleton. We developed novel, rapid techniques of spectral geochemistry to fingerprint skeletal growth banding in cores taken from giant, centuries old Porites with unprecedented, weekly resolution.As a primary objective, we will determine natural levels of seasonal river runoff (TE; organics) and sea surface temperature signals due to climatic base level changes over the past ~100 years, foremost of interannual to decadal-scale variability (El Niño/La Niña) and intermittent extreme erosion events along the path of heavy monsoon weather events. As a secondary objective, we will assess anthropogenic impacts on river runoff impacting the Miri-Sibuti Marine Park as offsets from the climatic baseline levels.
This project is funded through Curtin University Sarawak in Malaysia in collaboration with Curtin University Perth, Australia. International students are welcome to join the research activities as part of overseas Masters thesis studies.
Evaluating current responses and projecting the effects of climate change on WIO coral reef ecosystems from historical environmental variability (Western Indian Ocean Marine Science Association (WIOMSA– MASMA grant)
Projecting and predicting the future effects of climate change is the first step in preparing a response that can evaluate the potential impacts on coral reef social-ecological systems. The opportunity to improve future projections is based on the accumulating information contained in coral cores and satellite data that have been collected during the past decade, which can form a basis for determining the temporal and spatial variability and how this is likely to change in the coming years. These data can, in principle, be priors in Bayesian predictive models that can be used to make predictions on future states of the environment. Additionally, the ability to predict current temperature stresses and bleaching has improved such that the probabilities of bleaching can be predicted for certain places at periods of 2 to 3 months before the impact. The proposed work will use these sources of information to develop a map of the projected changes in environmental conditions and to undertake field research in areas prior to and after the temperature anomalies to determine the impacts of current stresses on key metrics of the coral reef ecosystem including coral health, symbionts, reproduction, recruitment, and fish populations. These two studies, when combined, can be used to parameterize an existing coral reef ecosystem model to generate projections of regional ecosystem responses to future climate change scenarios.
This project is a collaboration with the Wildlife Conservation Society and the Western Indian Ocean Marine Science Association WIOMSA, as well as the Australian Institute of Marine Science.