Effects of flow regulation on the movement patterns and habitat use of a potamodromous cyprinid species

Abstract

River regulation for hydroelectricity production results in rapid changes of flow and habitat features, but its effects in the movement patterns of freshwater fish are not well understood. Radiotelemetry was used to track Iberian barbel during a year cycle in non-regulated and regulated rivers. We applied a kernel density method to estimate and compare home range sizes of the two populations. Seasonal patterns of movement and the intra-annual variation in habitat preferences were also compared. Barbel inhabiting regulated river exhibit larger and more continuous home and core ranges, in opposition to the smaller and patchy areas used by fish inhabiting the non-regulated river. Seasonal movements of both populations were differentiated by the drought period. Barbel from the non-regulated river had to search for suitable refuges, with specific habitat characteristics, in which they remained aggregated during harsh summer conditions. Conversely, barbel from regulated river kept a continuous distribution along the river. This study contributes to the management of regulated rivers by providing insights about which flow components are more altered by hydropeaking operations and which are the most critical annual periods for fish movements. It also suggests several restoration actions, such as the protection of fish summer refuges, the restoration of large-scale temporal streamflow variability and the reduction of daily rates of discharge rise and fall, which should be continuously monitored in order to increase their efficiency and provide new knowledge.

Individual movements, home ranges and habitat use by native rheophilic cyprinids and non‐native catfish in a large regulated river

“…The evaluation of HR depended mainly on the number of individual localisations recorded, the duration of the study and the telemetry equipment (Alexandre et al., ). As in most telemetry studies, seasonal HR and the estimated Dn only partially reflected reality, as fish inevitably travelled outside the tracking periods during other moments of the daily cycle (evening and night‐time, e.g.…”

“…Horký, Slavík, Bartoš, Kolářová & Randák, ). However, it seemed reasonable to consider in this study that the use of a weekly positioning interval for the three species over 7 months was an appropriate way to compare relative mobility patterns among species on a seasonal scale, with acceptable losses of accuracy (Alexandre et al., [monthly basis; in a stream]; Baras, [test for successive locations from 1 to 28 days; best cost‐effectiveness for barbel = once a week; in a stream]; Hann & Schramm, [once a week for 5 months; in a river]; Herrala et al., [once a month for more than 3 years; in a river]; Ovidio et al., [every day to three times a week; in a stream]). HR for barbel and chub (median >2,300 m; Table and Figure ) were larger than catfish (median <1,300 m; Table and Figure ), with considerable individual differences.…”

“…() and Alexandre et al. (), who tracked fish over long distances (20–38 km) during 9–14 months on a weekly basis using boats.…”

Effect of short-term regulated temperature variations on the swimming economy of Atlantic salmon smolts

“…On one hand, ecological effects of hydropeaking on fish behaviour are well known (Taylor et al ., 2014; Alexandre et al ., 2015; Boavida et al ., 2016) On the other hand, physiological effects (e.g. swimming demand, oxygen consumption and internal temperature regulation) caused by the increased environmental variability are, until this date, still poorly understood (Geist et al ., 2005; Taylor et al ., 2014).…”

Development of an Evaluation System for Sustaining Reservoir Functions—A Case Study of Shiwen Reservoir in Taiwan

“…For example, Morrison et al [69] used IHA to assess the impacts of environmental flow on reservoir and recreational operations. Nikghalb et al [44] as well as Alexandre et al [70] used Q 95 to evaluate impacts of flows on movement patterns and habitat. They also determined ecological flow using WUA, and compared these results with Q 95 results.…”