The new box corer, developed by researchers at Stockholm University and Gothenburg University, can collect samples of soft sediment that are almost completely undisturbed. This should allow the amount of carbon stored in the ocean floor to be more accurately assessed in the future.

An improved device for samplinge of marine sediments.
An improved device for samplinge of marine sediments.
 

- For decades, scientists have relied on equipment that in practice has functioned poorly. We now need to re-evaluate the calculations based on previous measurements says Sven Blomqvist, a researcher at the Department of Ecology, Environment and Plant Sciences, Stockholm University.

Instruments for sampling bottom sediments were first invented over a hundred years ago. Some improvements have since been made, but generally without critically examining how effective they really are. In developing the new device, researchers first carefully recorded – by means of in-situ measurements, video recordings and scuba diving – how traditional instruments really work. This made it apparent that improvements were needed. The new sampling instrument provides sediment cores of much better quality, in terms of the content of carbon, nutrients and bottom-living fauna.

The improved sampling instrument in cocked state, from the side and in cross section.
The improved sampling instrument in cocked state, from the side and in cross section.
 

The greenhouse effect is largely driven by the increasing amount of carbon dioxide accumulating in our atmosphere as a result of rampant fossil fuel use. One possible option for reducing this atmospheric carbon dioxide is to enhance its fixation in the ocean and storage in the ocean floors. Dead algae and other organic matter sink slowly to the bottom, and are to some extent sequestered in the sediments. This process slows the increase of the greenhouse effect, and therefore needs to be carefully investigated. Samples of soft sediments collected with reliable methods are a crucial prerequisite for such studies.

The new instrument is described in the article Long overdue improvement of box corer sampling in the journal Marine Ecology Progress Series (538: 13-21).