Marine Biologist Raina Hristova To Track Anthropogenic Pollution in Livingston Island Littoral Zone

Seafloor sediments can be seen as a reservoir trapping traces of anthropogenic pollution, marine geologist Assoc. Prof. Raina Hristova from the Institute of Oceanology at the Bulgarian Academy of Sciences said in an interview for BTA. Hristova is part of the 31st Bulgarian Antarctic expedition and will study the seabed sediments in Livingston Island’s coastline.

Together with Assoc. Prof. Lyubomir Kenderov, Hristova is working on a project for integrated research of sediment, biota and waters in the marine ecosystem of the Bulgarian Antarctic base’s littoral zone. The project combines biological and geological research over a two-year period starting from 2023.

Hristova is focusing on seafloor sediments which are part of the ocean ecosystem. They are a component that is changing and continually experiencing the effects of climate change because, by their very geological nature, these bottom sediments are dynamic physico-chemical systems that have not yet evolved into rock types. Thus, they can record traces of impact phenomena, of geological processes that are of interest to in the context of climate change, and the aim is actually to study the rate and pace of the sedimentary process in the Livingston Island offshore area, she says.

That sediments can be seen as a reservoir trapping traces of anthropogenic pollution is another project task. This could be proven by a series of analyses, such as the presence of microplastics, organic substances and hydrocarbon indications, Hristova explained. 

The tool that will be used to study the sediments is a gravity tube, which the experts at the Institute of Oceanology have been using for many years to study the Bulgarian shelf, the marine geologist explained. It is a 5-6 metre long metal tube that is driven into the sediments, filled with samples (ed. note: the tube will be lowered to the seabed via a U-shaped frame from the stern of the Bulgarian naval research vessel Sv. Sv. Kiril i Metodii). Once on board, the actual geological work begins - lithological description, stratigraphic sequences, sampling. The aim of the expedition is to carry out a first exploratory descent of the pipe to give an initial idea of the bottom sediments in the Livingston area as a possible step towards a larger future monitoring project, said Hristova.

The aim is to cover a certain area around the island with many points of sample taking. Most importantly, these points need to be both geological and biological sampling points to meet the project objectives. A single lowering of the gravity pipe will sample the sediment, biota and the water layer immediately above the sediment at that point, Hristova noted.

Building on all the data collected from the analyses, the final stage of the project will draw general conclusions about how climate fluctuations affect the ocean ecosystem.

BTA's Daily News editor Konstantin Karagyozov is the only member of the media who is travelling on board the ship to Livingston Island and back, and will cover the Bulgarian expedition on site throughout the stay in Antarctica. All media outlets can use the Bulgaria-Antarctica BTA's Log for free.