An aquaculture container element (1) in the form of a panel (2) having a surface suitable for the growth of aquatic organisms thereon is provided that can be assembled together with other similar elements to form a composite aquaculture container. The panel has, extending along two opposite side edges (3), an integral sidewall section (6) that has an opposite free edge (13) lying in a plane that is parallel to that of the panel, but spaced therefrom. The elements can be assembled with the free edges of the sidewall sections of one element engaged with another element in a series thereof to form a series of parallel panels held in spaced relationship by means of said sidewall sections that together define composite aquaculture container sidewalls. Various other attributes of the container elements are described as well as an assembled container and a method of using it in which elements can be added or removed during use.
