Reconstructing the pollution history of southeast Asian wetlands...by Stefan Engels

Stefan with field assistant Charlotte (MRes student
from Keele University) collecting plant samples.

How time flies! It has only been about 4 months since I started my new job as a research fellow with  Melanie Leng and Suzanne McGowan within the Centre for Environmental Geochemistry. The main aim of my research project is to reconstruct the pollution history of southeast Asian wetland systems, and one of the first locations that we selected as a study-site was Tasik Chini on the Malaysian peninsula, here I tell you about progress to date... 

Preliminary laboratory data obtained from short sediment cores that had been previously collected shows the first evidence of recent ecosystem change. To be able to study this in more detail, and to ensure that we have samples that predate the recent period of extensive human impact on the environment, we decided to revisit Tasik Chini this spring with the main goal of collecting longer sediment cores, hopefully dating back several thousands of years. I say ‘hopefully dating back’, as scientific data on this tropical wetland ecosystem is extremely sparse. We basically don’t know when or why it formed, nor did we know how long the sedimentary record goes back in time. Therefore, this project will yield a lot of surprises!

Suzanne showing some of the core sediments we collected from Tasik Chini.

On the 18th April I flew to Kuala Lumpur where I am met with Suzanne McGowan and Ginnie Pannizo (both University of Nottingham). We participated in a local workshop in Kuala Lumper on projects across SE Asia, followed by a great evening lecture by Professor David Taylor (National University of Singapore) on geostatistics, insect-borne diseases and climate change. A truly interdisciplinary topic! We then drove east to the more rural area of Pahang. On the 4-hr long drive I couldn’t help but marvel at the scale of impact that the Malaysian economy has had on the landscape: we basically don’t see anything but oil palm plantations. 

The core sediments have arrived
safely back in the UK!

Taking wetland core sediments in the tropics turns out not to be unlike coring in the subarctic, which is where I’ve done most of my previous fieldwork. One noticeable difference is the coring equipment: whereas the metal extension rods can freeze together in the subarctic, in Malaysia they get so hot that they left some of our field crew with some serious blisters! I was also kept awake by geckos that were “chatting” in my room all night (not something that happens in the subarctic). The trip was very successful though, we managed to collect long sediment cores from a number of locations across the wetland. I am now back in the UK and are subjecting these cores to a range of different laboratory-based analyses, ranging from classic measurements of the amount of carbon to modern molecular approaches where we can find out where the carbon came from (agriculture, mining, sewage). While the results of the project will take some time to become available, the memories of doing fieldwork in an area that is full of monkeys, monitor lizards and geckos will remain with me for quite a while.


Stefan Engels is a Research Fellow within the Centre for Environmental Geochemistry (University of Nottingham and British Geological Survey).