Oxygen Depletion Affects Kinematics and Shoaling Cohesion of Cyprinid Fish

Numerous anthropogenic stressors impact rivers worldwide. Hypoxia, resulting from organic waste releases and eutrophication, occurs very commonly in Mediterranean rivers. Nonetheless, little is known about the effects of deoxygenation on the behavior of Mediterranean freshwater fish. To fill this knowledge gap, we assessed the impact of three different dissolved oxygen levels (normoxia, 48.4%, 16.5% saturation) on kinematics indicators (swimming velocity, acceleration, distance traveled) and shoaling cohesion of adult Iberian barbel, Luciobarbus bocagei, a widespread cyprinid species inhabiting a broad range of lotic and lentic habitats. We conducted flume experiments and video-tracked individual swimming movements of shoals of five fish. Our results reveal significant differences between the treatments regarding kinematics. Swimming velocity, acceleration, and total distance traveled decreased stepwise from the control to each of the two oxygen depletion treatments, whereby the difference between the control and both depletion levels was significant, respectively, but not between the depletion levels themselves. Shoaling cohesion showed dissimilarities between the treatments regarding the maximum distance between fish, as the high depletion treatment differed from each of the other two, indicating that under severe oxygen depletion some individuals move away from the shoal. Overall, our results show how oxygen depletion changes fish behavior, which may entail ecological responses, highlighting the need to maintain an unfragmented river network to ensure movement dispersal among habitats, thus providing conditions for species escapement from hypoxia.

[1]  M. Regan,et al.  Can variation among hypoxic environments explain why different fish species use different hypoxic survival strategies? , 2018, Journal of Experimental Biology.

[2]  T. Hein,et al.  Macroinvertebrate short-term responses to flow variation and oxygen depletion: A mesocosm approach. , 2017, The Science of the total environment.

[3]  J. Steffensen,et al.  The effect of hypoxia on fish schooling , 2017, Philosophical Transactions of the Royal Society B: Biological Sciences.

[4]  M. T. Ferreira,et al.  Potamodromous fish movements under multiple stressors: Connectivity reduction and oxygen depletion. , 2016, The Science of the total environment.

[5]  F. Shijian,et al.  The effect of group size on school structure in juvenile black carp , 2016 .

[6]  Julia Howitt,et al.  Hypoxia, Blackwater and Fish Kills: Experimental Lethal Oxygen Thresholds in Juvenile Predatory Lowland River Fishes , 2014, PloS one.

[7]  Paulo Branco,et al.  Pool-Type Fishways: Two Different Morpho-Ecological Cyprinid Species Facing Plunging and Streaming Flows , 2013, PloS one.

[8]  N. Herbert,et al.  The Effect of Hypoxia on Fish Swimming Performance and Behaviour , 2013 .

[9]  M. T. Ferreira,et al.  Ecohydraulics of pool-type fishways: Getting past the barriers , 2012 .

[10]  P. Poncin,et al.  Shoals and schools: back to the heuristic definitions and quantitative references , 2012, Reviews in Fish Biology and Fisheries.

[11]  D. McKenzie,et al.  A relationship between metabolic rate and risk-taking behaviour is revealed during hypoxia in juvenile European sea bass , 2012 .

[12]  Noam Miller,et al.  Automated Tracking of Zebrafish Shoals and the Analysis of Shoaling Behavior , 2012 .

[13]  R. Rosenberg,et al.  Introduction to Environmental and Economic Consequences of Hypoxia , 2011 .

[14]  Damià Barceló,et al.  Water quality and assessment under scarcity: Prospects and challenges in Mediterranean watersheds , 2010 .

[15]  D. Gilbert,et al.  Impacts of hypoxia on the structure and processes in pelagic communities (zooplankton, macro-invertebrates and fish) , 2009 .

[16]  B. Menne,et al.  Impacts of Europe's changing climate – 2008 indicator based assessment , 2009 .

[17]  L. Chapman,et al.  Chapter 2 Behavioral Responses and Ecological Consequences , 2009 .

[18]  A. Lillebø,et al.  Nutrient dynamics in Mediterranean temporary streams: A case study in Pardiela catchment (Degebe River, Portugal) , 2007 .

[19]  L. Hansen,et al.  Potential impacts of global climate change on freshwater fisheries , 2007, Reviews in Fish Biology and Fisheries.

[20]  J. Steffensen,et al.  The effect of hypoxia on behavioural and physiological aspects of lesser sandeel, Ammodytes tobianus (Linnaeus, 1785) , 2007 .

[21]  L. Ribeiro,et al.  Impacts of climate change on water resources : a case-study for Portugal , 2007 .

[22]  F. Giorgi,et al.  Climate change hot‐spots , 2006 .

[23]  P. Collen,et al.  BIOCIDE TREATMENT OF PONDS IN SCOTLAND TO ERADICATE SIGNAL CRAYFISH , 2006 .

[24]  M. Landman,et al.  Relative sensitivities of common freshwater fish and invertebrates to acute hypoxia , 2005 .

[25]  John F. Steffensen,et al.  The response of Atlantic cod, Gadus morhua, to progressive hypoxia: fish swimming speed and physiological stress , 2005 .

[26]  Donald L. Kramer,et al.  Dissolved oxygen and fish behavior , 1987, Environmental Biology of Fishes.

[27]  J. Steffensen,et al.  The effect of progressive hypoxia on school structure and dynamics in Atlantic herring Clupea harengus , 2002, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[28]  J. Seager,et al.  Effects of short‐term oxygen depletion on fish , 2000 .

[29]  N. Prat,et al.  Water use and quality and stream flow in a Mediterranean stream , 2000 .

[30]  V. Resh,et al.  Streams in Mediterranean Climate Regions: Abiotic Influences and Biotic Responses to Predictable Seasonal Events , 1999 .

[31]  W. Crampton.  Effects of anoxia on the distribution, respiratory strategies and electric signal diversity of gymnotiform fishes , 1998 .

[32]  J. Steffensen,et al.  SPONTANEOUS SWIMMING ACTIVITY OF ATLANTIC COD GADUS MORHUA EXPOSED TO GRADED HYPOXIA AT THREE TEMPERATURES , 1994, The Journal of experimental biology.

[33]  Göran E. Nilsson,et al.  Anoxic depression of spontaneous locomotor activity in crucian carp quantified by a computerized imaging technique , 1993 .

[34]  P. Fischer,et al.  In situ investigations on the respiration and behaviour of the eelpout Zoarces viviparus under short-term hypoxia , 1992 .

[35]  J. Steffensen,et al.  The influence of hypoxia on the preferred temperature of rainbow trout Oncorhynchus mykiss , 1991 .

[36]  W. Lewis.  Morphological Adaptations of Cyprinodontoids for Inhabiting Oxygen Deficient Waters , 1970 .