Abstract: An installation for in situ monitoring the quality of a habitat of aquatic organisms with minimal disturbance to the aquatic organisms. In a first aspect of the present invention, the monitoring installation uses invertebrate sentinel species such as mussels, clams, oysters and scallops. The monitoring installation comprises broadly, a buoy; a mooring and a monitoring apparatus comprising; a framework having an upper end connected to the buoy and a lower end connected to the mooring. There is also provided a camera attached to the framework. The camera is adapted for underwater operation and has image data generating and transmitting capabilities for transmitting a number of images to a remote receiver. A support structure is detachably mounted to the framework and has rotary retainers for movably supporting one or more socks of mollusks in front of the camera.