Biomineralization of microbes in natural and restored saltmarshes: a missing link in restoration efforts?

Saltmarshes are threatened coastal ecosystems, which are subject to cyclic variation in conditions which create a gradient-rich environment (e.g. salinity, pH). They support very diverse communities of plants and animals, protect the coast from erosion, and play an important role in element cycling and bio-remediation. The importance of saltmarshes has only been recently recognised, which has led to significant efforts in restoring sites that had been previously converted to Agriculture. Such restoration attempts have had limited success in returning these sites to their original biodiversity and biological structure. While not yet fully understood, it is thought that several factors are at play, including persisting differences in soil structure and quality. Coastal environments have been previously shown to harbour significant microbial populations capable of producing CaCO₃ biominerals. On the other side, CaCO₃ biomineral production is known to affect the texture and overall properties of soil, a property currently used in the improvement of soils for Agriculture. We suggest that these factors could be linked, and that the limitations of saltmarsh restoration efforts might result from differences in biomineral production. Our results provide an overview on differences between samples that we’ve collected in natural and restored sites, based on cultivation and screening efforts. Our insights might provide an important step forward in saltmarsh restoration and contribute to more successful approaches to protect these vital biotopes and increase biodiversity.