Fish guidance structure

A fish guidance rack for use in a fish guidance system in a watercourse, the fish guidance rack comprising a series of vertical bars mounted on a rack frame along a longitudinal axis of the fish guidance rack between a first end of the fish guidance rack and a second end of the fish guidance rack, wherein the bars each comprises a first, upstream half beginning with an upstream tip and a second, downstream half ending in a downstream tip, wherein the downstream half adjoins the upstream half in a downstream direction of the bar with respect to a flow direction of the watercourse in an installed state of the rack, wherein at least a number of the bars each comprises, at least along a part of a depth of the bar, a convex curvature of a first upstream side with respect to the first, upstream end of the fish guidance rack, wherein, in a horizontal cross section, the bars each comprises a maximum, first thickness in the first, upstream half of each bar, wherein the fish guidance rack comprises a minimum clear bar spacing between respective upstream halves of neighboring bars measured along the longitudinal axis of the rack, and wherein, in a downstream direction from respective locations of maximum, first thickness in respective upstream halves of neighboring bars to the respective downstream tips, a clear bar spacing between neighboring bars in the fish guidance rack either only increases or remains partially equal and partially increases.