This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: New research from the University of St Andrews shows that disturbing seabed sediments through trawling could cause significant losses of carbon stored in Scotland's sea lochs. The study, published in Marine Environmental Research, shows that organic carbon stored in seabed sediments can be released into the surrounding seawater when disturbed.
This carbon is then more likely to be broken down and ultimately returned to the atmosphere as carbon dioxide, contributing to climate change. The findings suggest that protecting specific areas of seabed, particularly at the heads of Scottish sea lochs, could play an important role in safeguarding natural carbon stores. Lead author Lauren South, a Ph.D. candidate in the School of Geography and Sustainable Development, supported by the Jane Lively Steward Ph.D.
Scholarship, said the research provides important new evidence about the vulnerability of these carbon-rich sediments. "Previous research showed that the seabed in our upper sea lochs stores substantial carbon, much of it sourced from runoff from peatlands," she said. "What makes these results so important is the use of sediment collected along the length of Loch Etive in carefully designed lab-based experiments.
Our results show that the maximum disturbance effects will be felt at the upper end of the loch, where the sediment is both high in organic carbon content and contains the most reactive forms of organic matter." The experiments found that even a single disturbance event could cause rapid losses of sedimentary organic carbon, with the strongest effects observed in sediments from the upper part of Loch Etive. "The results are startling, indicating that even a single disturbance event in these locations can cause very rapid losses of sedimentary organic carbon," South said. "This is part of a growing body of research that points in the same direction: If we care about natural carbon stores, it's time to protect the most vulnerable seabed carbon stores, particularly those at the heads of these sea lochs." Scotland's sea lochs, which scientists classify as fjords, are important natural stores of so-called blue carbon—carbon captured and stored in marine and coastal ecosystems.
They are estimated to bury about 84,000 metric tons of organic carbon each year, despite being a fraction of the size of the North Sea. Around 252 million metric tons of organic carbon is estimated to be stored within Scotland's sea lochs. Much of this carbon originates on land.
Rivers carry organic material, including carbon from surrounding peatlands, into the sea lochs, where it can become trapped in seabed sediments. The research suggests that these deposits are not equally vulnerable to disturbance. The upper reaches of sea lochs, where carbon-rich material accumulates, appear to be particularly sensitive.
Extract — continue reading at the source.
