Dataset for Impact of tide gates on the upstream movement of adult brown trout

Abstract

Three-hundred adult trout were caught between 0.5 and 6.0 km upstream from tide gates in the River Stiffkey, North Norfolk, UK, on 20 separate days between July and December 2011 (n = 15 per day) and implanted with 23 mm half-duplex Passive Integrated Transponder (PIT) tags before being released 15 m downstream from the gate where PIT antennas were located on either side. Overall, gate attraction (percentage of fish released that were detected by at least one antenna) and passage efficiencies (number of fish that passed Gate 1 reported as a proportion of those that approached) were 96.7% and 92.4%, respectively. The operation of an orifice, installed to improve connectivity for adult trout and juvenile eels, did not influence passage efficiency or delay. Of the fish that passed the gate when the orifice was operational, 42.6 - 55.7% approached the orifice entrance and 70.6 - 92.3% of these passed through. Individuals that passed through the orifice were larger than those that did not. Movement past the tide gates (median duration = 6.04 h) took 6 times longer than passage through two unimpeded reaches upstream. Duration of passage through the gates was predominately related to the mean angle of gate opening during the time prior to passage, followed by water temperature.