Details

Autor(en) / Beteiligte

• Leite, Tamara
• Branco, Paulo
• Ferreira, Maria Teresa
• Santos, José Maria

Titel

Activity, boldness and schooling in freshwater fish are affected by river salinization

Ist Teil von

• The Science of the total environment, 2022-05, Vol.819, p.153046-153046, Article 153046

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2022

Quelle

MEDLINE

Beschreibungen/Notizen

• Rivers are experiencing increasing anthropogenic pressures and salinity has shown to affect freshwater fish behaviour, potentially disrupting ecological processes. In this study, the aim was to determine the sub-lethal effects of salinization on freshwater fish behaviour, using a widespread native cyprinid species, the Iberian barbel (Luciobarbus bocagei) as the model species. Behavioural trials in a mesocosms setting were performed to assess the effects of three levels of a salinity gradient – control (no salt added to the water, 0.8 mS/cm), low (9 mS/cm), and high concentration (18 mS/cm) – on fish routine activity, shoal cohesion and boldness. Upon increasing the salinity levels in the flume-channels, fish showed a significant reduction on their i) swimming activity (76% of searching behaviour in the control vs. 57% in high salinity), and ii) shoal cohesion (0.95 shoal cohesion ratio in the control vs. 0.76 in high salinity), while iii) an increase of bolder individuals, measured by a higher number of attempts to escape the altered environment (106 total jumps in the control vs. 262 in high salinity), was simultaneously observed. Behavioural changes in fish can reflect shifts in ecological condition. Thus, the behavioural responses of fish caused by salinization stress should be further researched, in addition to the interaction with other environmental stressors, in order to understand the true scope of the consequences of salinization for fish species. [Display omitted] •Salinization of freshwater may have severe impacts on fish species.•Fish swimming behaviour response to salinity gradient was tested using mesocosms experiments.•Behavioural traits (activity, boldness, shoal cohesion) were monitored.•Fish were less active, bolder, and more disperse in response to increased salinity.•Acute salinity stress may affect fish behaviour.