Wildfires are a common phenomenon in Mediterranean regions that is becoming increasingly frequent and severe, causing several environmental concerns, of which ash runoff represents an important source of disturbance for aquatic organisms, in particular for fishes. Studies on the behavioural response of fishes to wildfire ash runoff are scarce and seldom include cyprinid species. The goal of this study was to investigate in a 3-artificial flume channel mesocosm, the behavioural and hepatosomatic condition responses of a native widespread potamodromous fish, the Iberian barbel (Luciobarbus bocagei), previously exposed for 24 h to different concentrations of wildfire ashes: 0.0 g/L (the control, no ash), 1.0 g/L (low concentration) and 2.0 g/L (high concentration). Behavioural parameters included i) routine activity, ii) boldness and iii) shoaling cohesion. The hepatosomatic index (HSI) was further determined to assess the health condition of fish. Significant differences on fish behaviour parameters were detected between the control and the high concentration of ash. Accordingly, i) an increasing proportion of fish were found on resting activity (56.2% vs 30.6% in the control), whereas the proportion of fish on searching behaviour (58.4% in the control) decreased (41.5%); ii) the proportion of bolder individuals was found to decrease (42.5% in the control vs. 29.4%) and iii) the same trend was detected for shoaling cohesion (61.3% in the control to 33.8%, of all fish within a body length of each other). Such differences were paralleled by an increase in the HSI from 1.62% (control) to 2.40% (high concentration). The present study shows that even short duration exposure to ash-loaded runoff can alter fish behaviour and hepatosomatic condition and highlights the need to maintain an unfragmented river network, or, when this is not possible, to prioritize the removal or retrofitting of barriers to increase movement dispersal and provide conditions for species recovery from fire-disturbances.

野火是地中海地区的常见现象，变得越来越频繁和严重，引起了许多环境问题，其中灰烬径流是对水生生物特别是鱼类造成干扰的重要来源。关于鱼类对野火灰径流的行为反应的研究很少，而且很少包括鲤科鱼类。这项研究的目的是在3条人工水渠通道中进行调查，研究一种本地广泛分布的含铁鱼类伊比利亚bar鱼（Luciobarbus bocagei）的行为和肝体状况反应。），预先暴露于不同浓度的野火灰烬中24小时：0.0 g / L（对照，无灰），1.0 g / L（低浓度）和2.0 g / L（高浓度）。行为参数包括：i）日常活动，ii）勇敢和iii）浅滩凝聚力。进一步确定了肝体指数（HSI）以评估鱼的健康状况。在对照和高灰分之间发现了鱼类行为参数的显着差异。因此，i）在静息活动中发现的鱼类比例增加（56.2％vs对照中的30.6％），而在搜寻行为中鱼类的比例（对照中的58.4％）下降（41.5％）；ii）发现大胆个体的比例下降（对照组为42.5％，而对照组为29.4％），iii）暗淡凝聚力的趋势相同（61。对照中的3％到33.8％，在彼此的体长之内的所有鱼类）。这种差异与HSI从1.62％（对照）增加到2.40％（高浓度）相对应。本研究表明，即使短时间暴露于含灰量的径流下，也会改变鱼类的行为和肝体状况，并强调需要保持无碎片的河网，或者在不可能的情况下，优先清除或改建障碍物以增加障碍运动扩散，并为从火灾中恢复物种提供了条件。