scholarly journals Longitudinal patterns in distribution of native and non-native fish species in a regulated temperate Neotropical river

2021 ◽  
Vol 33 ◽  
Author(s):  
Andrea Bertora ◽  
Fabián Grosman ◽  
Pablo Sanzano ◽  
Juan José Rosso

Abstract: Aim We evaluated the longitudinal patterns in distribution of native and non-native fish species in a hydrologically fragmented and environmentally variable lowland temperate river. Methods Four sites representing contrasting habitat and environmental conditions were sampled: a clear water reservoir, a turbid water lagoon and two river reaches with clear and turbid waters each. Environmental variables were measured in situ and in the laboratory. Fishes were sampled using trammel and beach seine nets. Results Two main environmental scenarios were identified: the upstream reaches, with colder, clearer and nutrient-oxygen poor waters (reservoir and its downstream river) and the downstream reaches, where turbidity, dissolved oxygen, water temperature, conductivity and nutrients largely increased (lagoon and its downstream river). Fourteen species with a high non-native/native (4:10) ratio were collected. Non-native species (NNS) were confined to lentic conditions, where the silverside Odontesthes bonariensis dominated. Native species (NS) better thrive in lotic conditions where the turbid scenario further favored tolerant species. Environmental conditions also seemed to influence the distribution of NNS. Fish assemblage structure considering either, all species, NNS or NS significantly differed among sampled reaches and habitat (lentic-lotic) conditions. Total fish abundance was higher in lentic reaches. Species richness and diversity were favored by the turbid scenario. Beta diversity was mostly explained by the replacement component revealing the substitution of species as the main pattern of variation. Water conductivity, nitrates and dissolved oxygen were the most important predictor variables in the best and most frequent explanatory models of fish assemblage structures. Conclusions Our results revealed that a low diversified Neotropical fish fauna is disrupted by habitat fragmentation due to the creation of artificial impoundments and the introduction of NNS. Environmental conditions further modulate the fish assemblage structure by affecting the distribution of species where tolerant species were favored by turbid, nutrient-rich waters with higher conductivity and pH.

2018 ◽  
Vol 69 (12) ◽  
pp. 1983 ◽  
Author(s):  
Raquel Coelho Loures ◽  
Paulo Santos Pompeu

In reservoir cascades, effects on fish assemblages are expected to strengthen over time and transfer from one reservoir to an adjacent one. To test this, fish-assemblage data from 23 years of monitoring in the Araguari reservoir cascade system, upper Paraná River basin, were analysed. The results showed a clear reduction in richness of native and migratory fish species and an increase of non-native species, following reservoir formation. Migratory species richness was higher in reservoirs that presented habitats similar to lotic stretches or tributaries upstream of the impounded area. There was a clear tendency for native species to decline and non-native fish species to increase, in a downstream direction. Fish assemblages became increasingly dissimilar as reservoirs became more distant from each other (longitudinal gradient) and were dominated by small and medium-sized species. Alongside longitudinal position, reservoir area, age and the presence of herbivorous non-native fish were found to be important predictors of variation in fish-assemblage structure. Results from the present study help clarify the potential accumulated impacts of reservoir cascades on fish diversity, which must be carefully considered in river-basin inventories for hydropower plants, and reinforce the importance of long-term monitoring, considering longitudinal and lateral dimensions of the basin.


2019 ◽  
Author(s):  
◽  
Landon Lee Pierce

To improve our understanding of lotic fish ecology and improve conservation efforts, I 1) identified potentially ecologically important tributaries (PEITs) and evaluated their effects on fish assemble structure, 2) evaluated factors affecting spatial transferability of species distribution models (SDMs), and 3) evaluated the drivers of non-native fish establishment in the Missouri and Colorado River basins (MRB and CRB). The effects of PEIT likely vary among rivers as all Missouri River PEITs affected fish assemblage structure, but only half of upper Colorado River basin PEITs affected fish assemblage structure. Species distribution models transferred from the MRB to the CRB for 15 of 25 species, but transferability was not predictable based on species characteristics, re-enforcing the hypothesis that transferability is species-and contextspecific. Support for Human Activity, Biotic Resistance and Biotic Acceptance hypotheses as the drivers of non-native fish establishment varied by family, but these hypotheses rarely explained significant variability in the probability of non-native Salmonidae, Catostomidae, and Cyprinidae occurrence. These results may suggest that other factors (e.g., natural factors) drive non-native species distributions at the spatial (i.e., grain-stream segment; extents-physiographic divisions, and MRB and CRB combined) and taxonomic (i.e., family) scales considered in this study. This study aids conservations efforts by providing an efficient approach for identifying ecologically important tributaries and improving predictions of non-native species establishment.


2019 ◽  
pp. 1430-1441
Author(s):  
Basim M. Hubain Al-Thahaibawi ◽  
Kadhim H. Younis ◽  
Ithar K.A. Al-Mayaly

The fish assemblage structure in Al-Huwaizah marsh, southern of Iraq was assessed. Fish samples collected monthly by different fishing means from period December 2017 to November 2018. A total of 28959 individual of fish belonging to 9 families and 19 species were collected, 11 of them of native species and 8 of alienspecies. The numerical dominance index value (D3) of the highest three abundant species comprised 74.26% of the total fish caught, included Planiliza abu (Al-Keshny) 38.2% ; Coptodon zilli (Tilapia red abdomen) 29.41% and Carassius auratus (Prussian carp) 6.65%. The total weight of fish caught 2,190,680 tan, highest weight 312,242kg achieved in July, while lowest weight 41,590 kg found in September. The weight dominance index value (D3) of the highest three species in weight recorded 1,409,973 tan of the total weight of fish caught included C. zilli(Tilapia red abdomen) 659,994 kg , S. triostegus (Jerry fresh water) 495,784 kg and O. aureus (Blue tilapia) 245,195kg.The annual rate value for diversity, richness and evenness indices amounted 1.88, 1.75 and 0.64, respectively. Some of physical and chemical properties were studied such as water temperature which ranged from 11.5°C in January to 31.02°C in August month, dissolved oxygen ranged from 2.24 mg/l in September to 9.9mg/l in February, salinity varied from 1.37‰ in November to 3.76‰ in September and pH which ranged from 7.4 in June to 8.15 in December.Jaccard Similarity Index (Ss%) was used to know the similarity degree between the monthly catch samples. Also associations between distribution of fish species and the environmental variables were quantified by using canonical correspondence analysis (CCA). 


2016 ◽  
Vol 116 (2) ◽  
pp. 36
Author(s):  
Thomas P. Simon ◽  
Charles Boucher ◽  
David Altfater ◽  
Dennis Mishne ◽  
Brian Zimmerman

Fish assemblage structure has changed dramatically in the Western Basin of Lake Erie since Trautman’s revision of the Fishes of Ohio. Fish surveys near the Bass Islands and adjacent mainland tributaries documented fish faunal distributional patterns during the last three decades. Recent collections (n=1,719 sites) from 1982-2014 indicate that 123 fish species are extant and 27 species have been extirpated from the Bass Islands and nearby tributaries draining the western basin. Extirpation of Polyodon spatula, Alosa sapidissima, Moxostoma lacurum, and Sander glacum occurred; however, A. sapidissima and members of genus Oncorhynchus were introduced and unable to naturalize. Recent collection of A. fulvescens in Schoolhouse bay near Middle Bass Island in May 2012; Umbra limi populations on Middle Bass Island and Kelley’s Island; and Lepisosteus oculatus populations along the southeastern shoreline of North Bass Island are stable in Lake Erie despite increased eutrophication. The current Western Basin fish assemblage includes 107 native, 26 nonindigenous, and 6 alien fish species. Twenty-one native species have been extirpated from Lake Erie, while 6 nonindigenous species have not naturalized and have been extirpated. Six additional species known from within the Lake Erie basin have not been collected from the Western Basin during the study period and current status is unknown. Introduced non-indigenous and alien species are responsible for increased species richness including Neogobius melanostomus, Proterorhinus semilunaris, Salmo trutta, Carassius auratus, Cyprinus carpio, Ctenopharyngodon idella and four records for Hyphthalmichthys molatrix since 1981. Brief comments on distribution, relative abundance, and status are provided for each species. 


2017 ◽  
Vol 29 (0) ◽  
Author(s):  
Carlos Mario Marín Avendaño ◽  
Néstor Jaime Aguirre Ramírez

Abstract: Aim The purpose of the present study was to examine spatial and temporal variation in fish assemblage structure associated with aquatic macrophytes in the littoral zone of the ASC. Methods Specimens were caught between January 2008 and February 2009, over four limnimetric moments, using both cast net and seine net. Data on the temperature, electrical conductivity, pH and dissolved oxygen was recorded for the characterization of the water mass in the sites. Results A total of 34,151 specimens from 44 species were collected. The most abundant species were Eigenmannia virescens, Astyanax caucanus, Astyanax fasciatus, Roeboides dayi and Cyphocharax magdalenae, which together accounted for more than 75% of the sample. Temporal and spatial comparisons showed variation in the environmental conditions and highlighted the existence of heterogeneous abiotic conditions (p<0.05). However, the multiple comparisons test showed the existence of homogeneous spatial conditions (p>0.05) regarding the fish assemblage structure. The multivariate analysis showed no significant relationship between existing environmental conditions and the fish assemblage (p=0.04). The analysis also showed the absence of a relationship between the fish assemblage and environmental variables with respect to the flood pulse and sampling sites (p>0.05). Conclusion The uniformity of the fish communities that inhabit aquatic macrophyte patches in the littoral region of the ASC may be related to the availability of suitable habitat in structural terms, that probably supports a more abundant and varied wildlife.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Łukasz Głowacki ◽  
Andrzej Kruk ◽  
Tadeusz Penczak

AbstractThe knowledge of biotic and abiotic drivers that put non-native invasive fishes at a disadvantage to native ones is necessary for suppressing invasions, but the knowledge is scarce, particularly when abiotic changes are fast. In this study, we increased this knowledge by an analysis of the biomass of most harmful Prussian carp Carassius gibelio in a river reviving from biological degradation. The species' invasion followed by the invasion's reversal occurred over only two decades and were documented by frequent monitoring of fish biomass and water quality. An initial moderate improvement in water quality was an environmental filter that enabled Prussian carp’s invasion but prevented the expansion of other species. A later substantial improvement stimulated native species’ colonization of the river, and made one rheophil, ide Leuciscus idus, a significant Prussian carp’s replacer. The redundancy analysis (RDA) of the dependence of changes in the biomass of fish species on water quality factors indicated that Prussian carp and ide responded in a significantly opposite way to changes in water quality in the river over the study period. However, the dependence of Prussian carp biomass on ide biomass, as indicated by regression analysis and analysis of species traits, suggests that the ecomorphological similarity of both species might have produced interference competition that contributed to Prussian carp’s decline.


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