Tychoplankton (Greek, "tycho", accident, chance) are organisms, such as free-living or attached benthic organisms and other non-planktonic organisms, that are carried into the plankton through a disturbance of their benthic habitat, or by winds and currents.[1] This can occur by direct turbulence or by disruption of the substrate and subsequent entrainment in the water column.[1][2] Tychoplankton are, therefore, a primary subdivision for sorting planktonic organisms by duration of lifecycle spent in the plankton, as neither their entire lives nor particular reproductive portions are confined to planktonic existence.[3]
They are also known as accidental plankton or pseudo-plankton (compare: pseudoplankton), although "pseudoplankton" also defines organisms that do not themselves float but, rather, are attached to other organisms that float.