A new fish-way, comprising variously-sized bed materials on a gentle slope, established on the Onga River estuary barrage was found to have 69 cobbles and boulders used as spawning nests of six goby species, including a threatened species, during the period from June 2013 to May 2014. Male body sizes were positively correlated with spawning substrate. In addition, wide salinity variations recorded over the fish-way during high tides on either side of spring tide were also implicated in goby spawning site selection.
