DeepCHALLA hits Stockholm…by Heather Moorhouse

Heather presenting her poster at IPA-IAL with DeepCHALLA principal
investigators Prof Phil Barker (Lancaster) and
Prof Melanie Leng (BGS/Nottingham)
In June 2018, scientists interested in the study of mud found at the bottom of lakes met for the first joint meeting of the International Paleolimnology Association and International Association of Limnogeology (IPA-IAL) at Stockholm University in Sweden to “unravel the past and future of lakes”.

Considering lakes are important sources of freshwater, stores and sinks of carbon and provide us with a wealth of other services, the more we can understand about these incredible ecosystems will ultimately help us to protect them from environmental degradation. Studying the sediment found at the bottom of lakes which builds up over time allows us the ability to investigate how the lake and its surrounding landscape has changed from the past to the present. This can then help us to predict what may then happen in the future. The IPA-IAL meeting was a chance for researchers around the globe to discuss progresses made in using lake sediments to understand human impacts, climate change, landscape and ecological evolution and natural hazards.

Scientists working on the International Continental scientific Drilling Programme (ICDP) led project DeepCHALLA (see my previous blogs!) were present at IPA-IAL to update other leading researchers on our investigations of  ~250,000 years of environmental change in equatorial east Africa. We are using sediments retrieved from the bottom of Lake Chala, which is found directly on the Kenyan, Tanzanian border. Inka Meyer from Ghent, Belgium presented work on how we can use the grain size and mineralogical composition of the terrestrial (land-based) components of the sediment. This can help us to understand whether wind or run-off was delivering this material to Lake Chala and so, tells us about the changing climate and landscape. Maarten van Daele also from Ghent, Belgium discussed how turbidites or sediment disturbances can deliver material from shallower depths to deeper depths. Often this material contains fossils such as fish teeth, and invertebrates that aren’t normally deposited at deeper depths where sediment cores are usually taken. This has the potential to help us understand changes to these ecological communities more thoroughly. Aihemaiti Maitituerdi from Haifa, Israel presented methods on investigating the geophysical record to understand changes to the lake level at Chala, which can help understand changes to past hydrology and climate.

Finally, I presented a poster on our work at BGS and Lancaster University, which is looking at the biogeochemistry of phytoplankton in the sediments of Chala to see if we can identify and constrain the African Megadroughts thought to have occurred 130 to 90 thousand years before present. These Megadroughts were periods of severe aridity lasting thousands of years and are believed to be important in the evolution and dispersal of our hominin ancestors from the region. Those working on DeepCHALLA look forward to continuing the exciting discussions and future work that was presented at IPA-IAL.

No conference studying things under water is complete without a boat trip. Some delegates elected a cruise around the Swedish archipelago and learnt about islands named after each day of the week according to when the farmers would row their livestock to each island to let them graze. The conference dinner featured a surreal evening of entertainment, with musical tributes to the nations sweethearts: ABBA.

Thanks to the conference organisers and committees of IPA and IAL for hosting a fantastic meeting.
Heather Moorhouse is the new Early Career Representative for the IPA and encourages anyone who wants to get involved to get in touch via twitter @H_Notts or email: