A device for example for the harvesting of farmed bivalves (6) in water (4), the bivalves (6) being attached to and growing on a bivalve net (10) in the water (4). According to the invention, the device, a bivalve harvester (2), has a propulsion device arranged thereto, and is formed of a frame with for example at least one rotatable harvesting roller (90, 92), which is pressed and rotated against the bivalve net (10) and the bivalves (6) during the harvesting of the bivalves (6), so that the bivalves (6) are thereby scraped or milled loose from the bivalve net (10), after which the bivalves (6) are collected and sucked into a catching device enclosing the harvesting roller(s) (90, 92). The bivalves (6) and bivalve bunches (8) are then pumped by means of a pumping device in a downstream direction into a pipe for further transport and collecting onto a vessel or a device placed in the vicinity of the bivalve harvester (2). Bivalve bunches (8) may possibly be separated into smaller units in a debunching pipe (192) placed for example immediately downstream of the catching device.) that functions as attachment body for a tool (1) or for the target objects (25) is placed.
