Cold-Water Carbonate Bioconstructions

Cold-water carbonate bioconstructions are the product of complex interactions between calcifying organisms and the surrounding environment, and deeply contribute in affecting the evolution of the submarine landscape in space and time. Important variables contributing to their development, growth and/or demise include sedimentary dynamics, food supply, physical and chemical characteristics of water masses and local hydrodynamic regimes. Geomorphological studies of bioconstructions are therefore critical in deciphering the physical and biological processes contributing to their development. The aim of this chapter is to summarise the state of the art of geomorphic studies on temperate coralligenous bioconstructions and cold-water coral reefs/mound systems, both representing the two most important and largest carbonate bioconstructions in temperate and deep-sea waters. The importance of these biogenic constructions covers several aspects. They can represent important carbonate factories of the deep sea, archives of past climate and oceanographic conditions and they support increased species diversity and complex biotic interactions with respect to the surrounding seafloor. Because of their remote location (from hundreds to thousands of meters below sea level), only since the last tens of years, technological advances are allowing fine-scale physical and ecological investigations of these bioconstructions, containing ecosystem engineers able to strongly modify the landscape heterogeneity. An increased awareness of their potential extension and significance as natural resource, is now steering scientific efforts towards the need to overcome the gaps in knowledge and contribute to prevent their vulnerability to an increasing human pressure