Concentrated seabed deposits of polymetallic nodules, which are rich in economically valuable metals (e.g., copper, nickel, cobalt, manganese), occur over vast areas of the abyssal Pacific Ocean floor. Little is currently known about the diversity of microorganisms inhabiting abyssal habitats. In this study, sediment, nodule, and water column samples were collected from the Clarion-Clipperton Z...

The resuspension of sediment by waves or currents is a major cause of turbidity in many shallow waters. Here we show that bottom-feeding fish greatly facilitate this process by reducing the erosion resistance of the sediment. We use a fish-removal experiment from a large Dutch lake to show that the absence of fish makes sediment resistant to wind effects, and we use controlled lab experiments t...

A mathematical model is used to investigate the role of sedimentation and remineralization in the sediment on nitrogen (N) dynamics in intensive shrimp culture ponds. The model describes the key processes involved in N cycling that underpin the dynamics of total ammoniacal N (TAN), nitrate/ nitrite (NOX) and chlorophyll a (CHL) concentrations and the sediment N pool. These parameters may, in hi...