How Eroded Seabed Rocks Provide Essential Nutrient Sources for Marine Organisms, Study

According to a study by researchers from the University of Leeds, eroded seabed rocks provide essential nutrition for drifting marine organisms at the base of the food chain.

The findings show that iron -- a vital nutrient for microscopic marine algae, like phytoplankton -- is released from sediments on the deep seabed.

Iron Nutrition From Deep Seabed Erosion

Contrary to expectations that oxygen in the seabed prevents dissolved iron from escaping the seafloor, research shows that a combination of organic matter and oxygen may encourage the release of iron from eroded sediments into the ocean.

Published in the journal Proceedings of the National Academy of Sciences entitled "Iron colloids dominate sedimentary supply to the ocean interior" the study could influence future studies on ocean carbon cycles and management of marine environment considering the effects of seafloor processes on overall marine ecology.

Dr. Will Homoky, lead author and a University Academic Fellow at Leeds' School of Earth Environment says that the researcher's findings reveal that the shallow surface of the deep seabed provides a crucial source of iron--a scarce micronutrient, for the marine organisms.

He adds that the study shows how the degradation and erosion of rock minerals alongside organic matter and oxygen acts as a recipe in producing tiny rust particles that are small enough to be dissolved and carried across the seawater.

Homoky explains that the minuscule rust particles and their chemical signatures elaborate how iron found in larger parts of the ocean interior could possibly have come from deep seabed sediments which weren't believed to be possible until today.

(Photo: Photo by Ben Idris from Pexels)

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Marine Organisms and Colloids

Colloids are nanometre-sized iron particulates that could provide an essential source of nutrition for marine microorganisms such as phytoplankton, which, in turn, provides the primary food source for a vast range of sea creatures, overall affecting the global food chain.

Phytoplankton isn't just a food source, they are also vital amidst the rising global pollution levels. The microscopic organisms help remove roughly a quarter of CO2 in the ocean emitted to the atmosphere annually.

Homoky and his team, funded by the Natural Environment Research Council, are comprised of scientists from the universities of Liverpool, Oxford, Southampton, South Florida, and South California forming a collaboration through the international GEOTRACES program.

The findings will be of significance in future studies of the processes that regulate iron occurrences in oceans, and the role they play in moderating marine life and atmospheric carbon dioxide.

Homoky says that the findings mark a turning point in viewing iron supply from sediments and its reach on marine life paving a new way of thinking about the seafloor.

He adds that the discovery of iron colloid production is different from other forms of iron supplied to the ocean, will help researchers design new ocean models to re-evaluate marine life and climate connections to the deep seabed.

Researchers believe that the study not only helps unravel how iron contributes to past climatic variations but it also informs approaches on future marine conservation and management efforts.