Some startling effects of biologic factors on seafloor physical properties

Abstract

Recently, the biological impact on marine geophysics has received much interest. The question now is What types of impacts, how intense, and how changing? How can these impacts be understood and quantified, and then enacted in our practical predictive systems? Two dramatic examples from NW Europe. The acoustic response of the sandy seabeds is being altered by dense populations of species such as the invasive Ensis (i.e., a change of seabed properties). The same species forms a baffle that alters the seafloor response to flows, causing sediment trapping (i.e., a change of processes). At the sea surface, massive drifting rafts of detached bladder algae change the acoustic response of the sea surface and can attenuate surface waves. The rafts have seasonal and longevity attributes and can be tracked remotely, so effects on long-range underwater communications may be manageable. The Volkswagenstiftung, Office of Naval Research, NATO, and others have understood the significance and started to finance meetings, projects, and expert teams. To improve prediction capabilities, especially before at-sea operations, a close cooperation of biology and physical sciences is necessary. This can be achieved by two parallel approaches: (1) make existing bio- and geo-information compatible and (2) design new combined bio-geo experiments.