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Willem Renema

Dr. W. (Willem) Renema, Senior researcher - Tropical Benthic Foraminifera


Email: willem.renema@naturalis.nl
Phone: +31 (0)71 56 87 576
Room number: C01.11, Darwinweg 2


Research interest

Environmental change is a pervasive part of earth history, and modern reef-building corals have survived repeated and varied episodes of past environmental change. Documenting the ancient dynamics is essential to the understanding of tropical ecosystems and requires a large-scale interdisciplinary approach. Ecologists studying modern reefs are faced with the dilemma that they have few baseline data to model the impact of predicted environmental change. However, useful baseline information is available in the fossil record. 

Ecosystems are not static entities, but continuously change their composition in response to external drivers (e.g. temperature, nutrients), interactions between components, stochastic processes, and disturbance events. At longer time scales innovations interplay with these dynamic interactions. I am interested in how these dynamics are expressed over a multitude of spatial and temporal scales. From million years timescales across the entire tropical zone to interannual variation in assemblage composition in Recent reefs in selected areas in Indonesia.


benthic foraminifera, biodiversity, ct-scanning, tropical shallow marine ecosystems, paleoecology, stratigraphy

Current research topics

Holocene to Recent Indo-Pacific larger benthic foraminifera

Shallow marine environments in the Indo-Pacific harbour species-rich ecosystems, including vulnerable habitats such as reefs, seagrass meadows, and mangroves, and reefs. These habitats suffer from degradation due to direct (overexploitation, tourism, invasive species) as well as indirect drivers (coastal development, climate change causing bleaching events).

To document these changes most attention has been given to the eye catching ecosystems engineers. Ecosystem engineers modify, maintain, and create habitats, thereby modulating availability of resources for associated taxa (Jones et al., 1994; Jackson 2001). However, assemblage composition of the associated taxa might respond to different environmental parameters. Understanding (variations in) assemblage composition might provide valuable additional information about the state of the ecosystems. For example, large benthic foraminifera respond to water quality and nutrients (both availability and type), while otherwise having similar constraints as corals.

Diversity of larger benthic foraminifera is determined by the complex interplay of environmental parameters, among which nutrient availability, temperature, and disturbance frequency (the frequency at which stressful events occur) are very important. Stress events can be burial because of increased sedimentation rate, storms or bioturbation, but also breakage due to storms. By comparing recent distribution patterns of species with historical data, other long-term processes affecting larger benthic foraminifera diversity and ecosystem functioning can be determined.

My overall aim of is to develop a monitoring tool using LBF in sediment cores. In order to do so we do not only need to understand the geographical variability, but also the 10-1000 year natural temporal variation in LBF communities. Only then we can discriminate between natural variation and temporal trends.

Past Indo-Pacific marine biodiversity

Although the Indo-West Pacific (IWP) houses the most diverse extant marine ecosystems, little attention has been paid to the Cenozoic history of these diverse biotas. Most of the work on the fossil record of this area dates back to the first half of the twentieth century. Restudying collection material, combined with additional fieldwork in the area has shown that the modern centre of marine biodiversity is a relatively recent phenomenon. During the past 50 Million years, the marine biodiversity hotspot relocated from southwestern Europe to its present position.

Basic questions in paleobiodiversity research are: What is it (identification), where is it from (georeferencing), and how old is it (stratigraphy). I am specializing in a group that has a manageable size, yet sufficient turnover, and preserves well even in indurated rocks, the larger benthic foraminifera.


In the Indo-Pacific especially the late Paleogene (~33-23 million years ago) deposits are characterized by large carbonate platforms with mostly indurated rocks. Large benthic foraminifera make up a large part of the rock volume, and can still be identified at sufficient taxonomical resolution to offer valuable information on taxonomic turnover and regional biodiversity.


In a time of GPS devices, smart phones and tablets, georeferencing seems to be straightforward. However, the early 20th century collections do not come with coordinates, and are often only poorly documented on maps (if at all). These collections, however, are an important lead for our research since these demonstrate the availability of well-preserved fossils.


One of my focus points in this research concerns the stratigraphy of these localities. New techniques become available, and make it possible to increase stratigraphical resolution in the shallow marine environment to 1-2 My stratigraphic bins. This is achieved by integrating data sources, such as Strontium Isotope Stratigraphy, planktonic foraminifera stratigraphy, and calcareous nanoplankton.


Biotic and abiotic drivers of shifting marine tropical biodiversity hotspots during the Eocene-Oligocene

This is a collaborative project including Wout Krijgsman (paleomagnetic laboratory, University of Utrecht), and Paul Pearson (University of Cardiff). The project is funded by NWO-ALW.

Recently we demonstrated major redistributions in tropical shallow marine biodiversity patterns during the Cenozoic, especially the shift of maximum marine biodiversity from the western Tethys to Southeast Asia (Renema et al., 2008). The dominant drivers underpinning this pattern, and especially the role of biotic (extinction, dispersal and origination) and abiotic (climate, tectonics) drivers remains debated (Connolly et al. 2003; Fraser & Currie (1996); Hughes et al. 2002; Halas & Winterbottom 2009).

We will approach this problem from a new angle by analyzing occurrence data of Cenozoic large benthic foraminifera. We will add a latitudinal transect (Madagascar- Central Asia) to the already existing longitudinal dataset. Special attention is paid to the Eocene-Oligocene since this is a period of major changes in diversity patterns, and it includes a period of major biotic and climatic reorganization (e.g. review by Coxall and Pearson, 2007).

Specific aim of this proposal is to quantify the geographic variation in the contribution of extinction, dispersal and origination processes during the EOT biodiversity crisis in relation to regional climate change.


Benthic Foraminifera.



Renema, W., D. Bellwood, J.-C. Braga, K. Bromfield, R. Hall, K.G. Johnson, P. Lunt, C.P. Meyer, L. McMonagle, R.J. Morley, A. O’dea, J.A. Todd, F.P. Wesselingh, M.E.J. Wilson, and J.M. Pandolfi (2008) Hopping hotspots: Global shifts in marine biodiversity. Science 321: 654-657

Renema, W. & Troelstra, S. R. (2001) Larger foraminifera distribution on a mesotrophic carbonate shelf in SW Sulawesi (Indonesia). Palaeogeography, Palaeoclimatology, Palaeoecology 175: 125-147

Renema, W. (2006) Large benthic foraminifera from the deep photic zone of a mixed siliciclastic-carbonate shelf off East Kalimantan, Indonesia. Marine Micropaleontology 5873-82.

Renema, W. (2010) Is increased calcarinid (foraminifera) abundance indicating a larger role for macro-algae in Indonesian Plio-Pleistocene coral reefs? Coral Reefs 29: 165-173.

Batenburg, S.J., Reichart, G.-J., Jilbert, T., Janse, M., Wesselingh, F.P., Renema, W. (2011) Interannual climate variability in the Miocene: high resolution trace element and stable isotope ratios in giant clams. Palaeogeography, Palaeoclimatology, Palaeoecology 306: 75-81.

Cotton, L.J, Renema, W., and Pearson, P.J.(2014) Stable isotope stratigraphy and larger benthic foraminiferal extinctions in the Melinau Limestone, Sarawak.Journal of Asian Earth Sciences 79: 65-71

Clague, D.A., Braga, J.C., Bassi, D., Fullagar, P.D., Renema, W., Webster, J.M. (2010) Maximum age of Hawaiian terrestrial lineages: geological constraints from Koko Seamount. Journal of Biogeography 37: 1022-1033.

Cleary, D.F.R., Becking, L.E., Voogd, N.J. de, Renema, W., Beer, M. de, Soest, R.W.M. van and Hoeksema, B.W. (2005) Variation in the diversity and composition of benthic taxa as a function of distance offshore, depth and exposure in the Spermonde Archipelago, Indonesia. Estuarine, Coastal and Shelf Science 65: 557-570.

Evans, D., Müller, W., Oron, S., and Renema, W. (2013) Eocene seasonality and seawater alkaline earth reconstruction using shallow-dwelling large benthic foraminifera. Earth and Planetary Science Letters 381: 104-115.

Novak, V., Santodomingo, N., Rösler, A., Di Martino, E., Braga, J.C., Taylor, P.D., Johnson, K.G., Renema, W. (2013) Environmental reconstruction of a late Burdigalian (Miocene) patch reef in deltaic deposits (East Kalimantan, Indonesia). Palaeogeography, Palaeoclimatology, Palaeoecology 374: 110-122.

All publications on Google Scholar