Relationships between river flows and recreational catches of Australian bass

The relationship between river flows, summarized by hydrological indices, and catches of Australian bass Macquaria novemaculeata from recreational fishing competitions were examined in the Hawkesbury‐Nepean River system. Between 55 and 198 fishermen took part in six monthly fishing competitions. The number of hours fished increased from 570 to 1800 h between 1998 and 2001. A total of 11 275 Australian bass were caught over the study period. The percentage of young‐of‐the‐year (YOY) Australian bass and the catch of fish per unit effort was influenced by either the flow regime occurring in the same year and flow in the previous year. The number of Australian bass caught per unit effort was positively associated with the median volume of water and the number and duration of high flow events occurring in the previous year. The percentage of YOY Australian bass caught in any one year was positively associated with the median flow in the same year of capture and the maximum, mean and variation of daily flows, the number and duration of high flow events and the greatest rise and fall of daily flows in the previous year.