The present invention relates to a fish reef combined in three stages. The fish reef combined in three stages comprises: a first fish reef castle to construct an ecological environment suitable for a fish species swimming while a portion of a fish or the entire fish comes in contact with a fish reef; a second fish reef castle to construct an ecological environment suitable for a fish species swimming around the fish reef; and a third fish reef castle to construct an ecological environment suitable for a fish species swimming in a surface layer and a middle layer water zone separated from the fish reef. Ecological environments suitable for various fish species are constructed by the fish reef combined in three stages. Also, most of the first fish reef castle, the second fish reef castle, and the third fish reef castle are made of steel. Therefore, a product can be immediately produced once steel bars are welded at a site to be assembled. Therefore, a space required to cure concrete does not need to be secured, and waiting while concrete cures is not needed, thereby reducing overall manufacturing costs, shortening the construction period, and improving fish reef productivity.
展开▼
