Risk assessment of the aquatic ecosystem of the River Jadar is based on the composition and amoun... more Risk assessment of the aquatic ecosystem of the River Jadar is based on the composition and amount of wastewater that is to be processed and released into the stream. This study aimed to assess the effects of untreated wastewater on aquatic ecosystem components, presumably fishes, by simulating the accident. Methodology relied exclusively on the published documents that investors, "Rio Tinto'' and "Rio Sava Exploration" d.o.o., issued about the boron and lithium mine in the Jadar region of Serbia as the only source of the publicly available data about concentration of mineral contents in underground water. Results revealed that concentrations of boron in a range of 3.43-12058.83 mg l-1 and those of lithium in a range of 0.70-2452.50 mg l-1 in a stream water of the River Jadar would pose a great risk to aquatic ecosystem in any lapse in proper processing of wastewater at either average low-, medium-, or high-water levels. Such high contents would inevitably cause toxic, genotoxic and other pathological effects on aquatic organisms. Records published on the relevant in vitro models reveal that if the concentration of boron and lithium in the stream water would exceed safe concentrations, the ecosystem would be seriously harmed, especially for the fish that are most sensitive to metal pollution. Due to a lack of actual referent in-field data, it is difficult to predict either the extent of harmful effects on downstream sections, or the period the ecosystem would need to recover from high levels of pollution.
Climate change that has occurred at the end of the last and at the beginning of this century, amo... more Climate change that has occurred at the end of the last and at the beginning of this century, among other things, has a certain impact on forests as well. For the territory of Eastern Serbia, for two periods of climate observations, the reference period 1961-1990 and the period 1991-2012, a comparative analysis of the following climatic elements was done: air temperature, amount of precipitation and relative humidity of air. Calculations were performed on the basis of collected and systematized data from 11 meteorological stations (6 synoptic/main climatological and 5 regular climatological) that were part of the Republic Hydrometeorological Service, situated in the area of Eastern Serbia. Analysis of the anomalies of air temperature and precipitation as indicators of climate change for the period 1991-2012 compared to the reference period 1961-1990 was done separately for each of the four seasons (winter, spring, summer, autumn) and summarized for each period. The results of the co...
Austropotamobius torrentium (Schrank, 1803) lives in two watercourses, namely Subotica (Sana) and... more Austropotamobius torrentium (Schrank, 1803) lives in two watercourses, namely Subotica (Sana) and Toplik (Tilava). The influence of the ecological conditions of these rivers on individuals of this species is analyzed based on 22 morphometric parameters. The assessment of abiotic conditions was done through the measurement of physical and chemical water parameters and the analysis of the composition of phytobenthos and macrozoobenthos. Sampling was carried out in June, September, and October 2021. Water quality at the investigated localities (on the basis of abiotic and biotic parameters) is oligo to betamesosaprobic. A total of 37 crayfish were analyzed (20 from Subotica and 17 from Toplik). Female crayfish have shown significant differences in the head width (HEW) and abdominal thickness (ABH). Males differed significantly in a number of parameters, including the weight (W), head shape (HEL and HEW), rostrum length (ROL), carapace width (CPW), and abdominal shape (ABH and ABL). Hig...
Huchen or Danube salmon Hucho hucho (Linnaeus 1758) is one of the largest salmonid species in the... more Huchen or Danube salmon Hucho hucho (Linnaeus 1758) is one of the largest salmonid species in the world and the largest species native to the Danube basin in Europe. In Serbia, this species inhabits the Drina river system, as well as the upper reaches of the River Ibar. It has already been introduced into the rivers Moravica and Đetinja, which are part of the Zapadna Morava catchment area. Most recently, huchen was stocked from its native habitat into the rivers Jerma and Nišava in the Južna Morava river system, and into the River Mlava which flows into the Danube. Huchen is listed as an endangered (EN) species on the IUCN Red List of Threatened Species and is protected in Serbia, and a Conservation Action Plan has already been adopted. In this report, we present the first record of this species in the River Grza, which is a part of the Velika Morava river system, outside its native range. The ichthyofauna of this recipient river consists of brown trout Salmo trutta L. and Eurasian minnow Phoxinus phoxinus L. In a small river of a fragile ecosystem such as this, the introduction of huchen as an apex predator can seriously harm the species of the native fish community, which warns of the illegal stocking measures currently in process.
Brown trout is a common type of fish grown for consumption in open and flowing fish ponds on the ... more Brown trout is a common type of fish grown for consumption in open and flowing fish ponds on the rivers of Bosnia and Herzegovina. We conducted this study during three seasons (spring, summer and autumn) to obtain a complete picture of the morphological and histological characteristics of selected trout tissues. The physicochemical characteristics of the water from the Pliva River near Pljeva and the fish pond where intensive breeding of trout is carried out were analyzed. These analyses have shown that there are no major deviations in water quality and that the water in the pond is of excellent quality. A total of 90 trout were harvested during all three seasons and their morphometric characteristics were determined by analyzing ten parameters. After the dissection of all individuals, histological and stereological analysis was performed to compare the tissues of the liver, stomach, gills and muscles. These analyses showed significant differences in the histoarchitecture of selected trout tissues from the pond compared to the river. Liver tissue had altered hepatocyte shape and presence of adipocytes; stomach tissue had stronger mucosa and weaker muscle layer; gill tissue had lower respiratory lamellae; while muscle tissue had a significant presence of adipose tissue in brown trout living in the fish pond compared to those in the river. All these changes are due to the quality of commercial feed and the inability to move freely.
The handbook of environmental chemistry, Sep 24, 2014
On the survey of the recent records, the fish and lamprey fauna of the River Sava catchment consi... more On the survey of the recent records, the fish and lamprey fauna of the River Sava catchment consists of 74 species, 15 of which being considered alien. The indigenous species diversity, explained using the relation N = 0. 546 A 0.232, fits well into the range common for large catchments in Europe. Both taxonomic and ecological diversity, as well as the character of fish communities in streams and rivers, are strongly correlated with the stream order. On the relative abundance of species in fish communities, the upper rhithron fish communities cluster distinctly from those belonging to the middle rhithron, within which several subgroups of fish communities were distinguishable. Fish communities of the middle rhithron character in streams and small rivers stand distinctly apart from those belonging to particular sections of large rivers (e.g., the Rivers Sava, Drina, Vrbas, and Bosna), with the transitional type of middle rhithron fish community in larger rivers (e.g., those in the Rivers Una and Sana) that resemble more to the fish communities common in middle rhithron streams. Fish communities in the middle section of the River Sava in Croatia and in the bordering area with Bosnia and Herzegovina mainly belong to the lower rhithron, attaining the character of potamon in the most downstream, Serbian section. River Sava’s fish communities strongly interact with the ones occurring in the most downstream sections of their largest tributaries, e.g., the Rivers Una, Vrbas, Bosna, Drina, and Kolubara, which makes them very similar in structure in the areas of river mouths. Classification of fish communities based solely on the presence and absence of species revealed similar general pattern of fish community classification, though with the more sharp delimitation between those belonging to the upper and middle rhithron on one and to the lower rhithron and potamon on the other side. That was supported by the determination of fish communities belonging to the upper rhithron with brown trout Salmo cf. trutta, European bullhead Cottus gobio, and minnow Phoxinus phoxinus as the most common fish species. Fish communities belonging to the middle rhithron were determined mainly with chub Squalius cephalus and spirlin Alburnoides bipunctatus, whereas brook barbel Barbus balcanicus and stone loach Barbatula barbatula occurred in both upper rhithron and middle rhithron. Nase Chondrostoma nasus were associated with both middle and lower rhithron fish communities. The most common fish species that determine the lower rhithron fish communities were common bream Abramis brama, ide Idus idus, and bleak Alburnus alburnus, with the northern pike Esox lucius, Balon’s ruffe Gymnocephalus baloni, and racer goby Neogobius gymnotrachelus as significant species explaining fish communities of both lower rhithron and potamon. The level of production of fish in the River Sava varies remarkably within the sections with the similar ecological features, as well as between the sections that differ for the type of fish community. The greatest biomass and annual natural production were recorded in the sections homing the potamon and lower rhithron fish communities, especially in the flooding areas of side arms and oxbows which serve as spawning areas and nurseries. A total of 15 alien fish species was recorded in the River Sava catchment, the Prussian carp Carassius gibelio and brown bullhead Ameiurus nebulosus being assessed the most invasive in the areas with the potamon fish community. A strong impact from both long-term and recent stocking with alien hatchery-reared brown trout strains and rainbow trout in the upper rhithron fish communities was recently recognized. Mudminnow Umbra krameri and huchen (or Danube salmon) Hucho hucho are considered the two most threatened fish species of the River Sava catchment, where various types of riverbed modifications, especially the damming, were seen the most prominent threatening factors for fish diversity.
Amazon sailfin catfish Pterygoplichthys pardalis (Castelnau, 1855) (Loricariidae, Siluriformes) i... more Amazon sailfin catfish Pterygoplichthys pardalis (Castelnau, 1855) (Loricariidae, Siluriformes) is a new non-indigenous fish species recorded in the Serbian section of the Danube River, being reported for the first time in inland waters of Europe, as well. A single, female fish was ripe and in good shape, although considering its original neotropical dispersal area and recording of occurrence in summer, with the only single female individual, its acclimatization is not likely. However, both its estimated invasive potential after the FISK protocol scoring of 26 and the risk of its introduction and establishment in the recipient area in concern after the IFRA protocol scoring of 61 should be considered moderate. That, together with the invasive history of this sailfin catfish and its congeners in southeastern Asia and Meso-American region imposes a need for precaution.
Abstratct⎯The part of the River Danube basin in the Western Balkans region (11 sampled localities... more Abstratct⎯The part of the River Danube basin in the Western Balkans region (11 sampled localities and 57 in total with using of published data) revealed the remarkable diversity of brown trout assessed using the Control Region (CR) of mitochondrial DNA (mtDNA) as a molecular marker. The greatest number of brown trout populations holds brown trout of the Da1 haplotype. Particular distinct haplotypes are limited to isolated brown trout stocks. There are haplotypes of Danubian (Da), and those of Atlantic (At), Adriatic (Ad) and marmoratus (MA) lineages introduced there. Phylogenetic relationships inferred between them implicate the plesiomorhic character of Da*Vr, Da*Dž and Da-s6 haplotypes that were resolved as ancestral clades, with the intermediate position between clades holding haplotypes of the non-Danubian lineage and more advanced haplotypes of the Danubian lineage. A uniform rate of evolution was found for all clades. The recent widespread distribution and exclusivity of Da1 haplotype imply its ancestral character among advanced Danubian haplotypes. Populations in the Sava, Drava, Una and Drina revealed an expansion, whereas those in the Kupa and Zapadna Morava catchments revealed both stability in size and great differentiation. Gene flow between stocks was found to be negligible.
In the sample of 83 specimens of the perch (Perca fluviatilis L., 1758), caught on eight differen... more In the sample of 83 specimens of the perch (Perca fluviatilis L., 1758), caught on eight different sampling sites at the Vlasinsko Lake reservoir, in April-October 1993, 25 infested specimens were found. They were infested with the following species of parasitic ciliates: Trichodinella epizootica, Apiosoma robustum, Apiosoma piscicolum ssp. perci, Ichthyophthirius multifiliis, Chilodonella cyprini and Chilodonella hexasticha. The most intensive infestation with all quoted parasitic ciliates was registered in April. Only Ichthyophthirius multifiliis infested the perch intensively in July. Trichodinella epizootica and Apiosoma robustum revealed both the highest prevalence and intensity of infestation. Regarding the localization of the parasitic species, Trichodinella epizootica and Apiosoma robustum had a much stronger affinity for the gills than for the skin of the perch. studied in Yugoslavia, although they are the commonest parasites of the freshwater fish. In Vlasinsko Lake reservoir l6 fish species have been registered to date, the most numerous of which are Perca fluviatilis and Carassius auratus gibelio. 2. Material and methods 2.1. Locality description The Lake Vlasinsko is a reservoir, 12 km in length and of average width of 1 km (maximal width of 2.5 km). It is situated in the Southeastern Serbia, near the Bulgarian border, at 1 200 m above the sea level (42˚40′-42˚45′N, 22˚19′-22˚21′E).
A pool of data already existing about D-loop, i.e., the Control Region (CR) haplotypes of the mit... more A pool of data already existing about D-loop, i.e., the Control Region (CR) haplotypes of the mitochondrial DNA (mtDNA) of brown trout, Salmo trutta Linnaeus, 1758, tentative Adriatic trout Salmo farioides Karaman, 1938, and tentative Macedonian trout, Salmo macedonicus (Karaman, 1924), and their reconstructed phylogeography makes a good starting point for resolving their evolutionary history. That includes the dating of particular events in it. The events have hitherto been dated using the method of a molecular clock. Various calibrations were applied for the mutation rate, owing to the incongruence between the time of divergence that various authors notified and general knowledge about events in geological history and the periods in which they occurred in the Mediterranean region. Since geological history events were mandatory for setting the scene for the evolutionary history of brown trout, the incongruence between them has questioned the molecular clock calibration’s validity. ...
Salmonids are an extensively hatchery-reared group of fishes that have been introduced worldwide ... more Salmonids are an extensively hatchery-reared group of fishes that have been introduced worldwide mainly for their high commercial and recreational value. The Balkan Peninsula (south-eastern Europe) is characterised by an outstanding salmonid diversity that has become threatened by the introduction of non-native salmonids whose potential risk of invasiveness in the region remains unknown and especially so under predicted climate change conditions. In this study, 13 extant and four horizon non-native salmonid species were screened for their risk of invasiveness in the Danube and Adriatic basins of four Balkan countries. Overall, six (35%) of the screened species were ranked as carrying a high risk of invasiveness under current climate conditions, whereas under predicted conditions of global warming, this number decreased to three (17%). Under current climate conditions, the very high risk (‘top invasive’) species were rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta (sen...
An old male ship sturgeon Acipenser nudiventris caught in the middle Danube River at the river km... more An old male ship sturgeon Acipenser nudiventris caught in the middle Danube River at the river km 1390 near Apatin, Serbia is the first reliable record of the species since 1989 in the whole river basin.
Over the last 14 years, ichthyological and ecological parameters have been monitored in the Labud... more Over the last 14 years, ichthyological and ecological parameters have been monitored in the Labudovo okno Ramsar site. This area is important for its biodiversity as it is home to many rare and endangered plants and animal species. A total of 3861 fish specimens were sampled and measured at six sampling sites four times during the sampling period. An analysis of biodiversity indexes, relative biomass (kg/ha), and relative annual production (kg/ha) was carried out to assess the effectiveness of existing conservation measures. The results obtained show a trend decline in biodiversity, relative biomass, and relative annual production. This indicates a biodiversity conservation problem that should be addressed through other mechanisms in addition to the principles of the Ramsar Convention.
Small run‐of‐river hydropower plants (RRHPs) have revealed strong harmful effects worldwide on st... more Small run‐of‐river hydropower plants (RRHPs) have revealed strong harmful effects worldwide on stream habitats (e.g., fragmentation and destruction) and decreased fish species, especially anadromous species abundance. Recently, RRHPs have rapidly been installed in Serbia. Most were installed on montane streams because their steep slopes are most convenient for hydropower energy production at minimal costs. Brown trout Salmo trutta are prominent in the fish communities of this rarest type of aquatic ecosystems. Their native molecular diversity reflects a biodiversity hotspot in the Balkans, and they provide attractive fishing opportunities. Records from fishery management plans for highland stream fisheries where RRHPs were installed revealed reduced brown trout biomass compared with streams without RRHPs. Research on six streams with operational RRHPs revealed severe deterioration of habitat, for example, increased water temperature, reduced dissolved oxygen, and increased nutrient contents. Effects on fish communities were evident from a change in their structure. Resident, stream‐dwelling brown trout were the most affected species with steep declines in abundance, biomass, and productivity. Fragmentation owing to damming was also reflected by deterioration of their age structure. Unique native brown trout stocks susceptible to adverse effects are difficult to restore by stocking, and fish passages commonly supplied as compensation to overcome the disruption of habitats cannot mitigate the threat posed to the fish.
Background. The diversity of wild trout stocks in Montenegro is compromised by insufficiently con... more Background. The diversity of wild trout stocks in Montenegro is compromised by insufficiently controlled stocking. Adriatic and Mediterranean areas show a high degree of endemism of the salmonid species, with numerous native Salmo taxa described. The invasive effect of brown trout, Salmo trutta Linnaeus, 1758, of the Atlantic haplogroup on the endemic Adriatic trout, Salmo farioides Karaman, 1938, in the drainage area of the Adriatic Sea basin is lower compared to the effect inflicted by S. trutta has on Salmo labrax Pallas, 1814 of the Danubian haplogroup. The presently reported study was intended to describe the genetic structure of the population of Adriatic trout, Salmo farioides, from the Mrtvica River, a right tributary of the Morača River, Montenegro, in order to get an insight into the spread of non-native strains and their introgression into the native Adriatic trout gene pool. Material and methods. Trout specimens sampled from the lower section of the Mrtvica River from 2004 to 2007, and from its upper section in the spring of 2014, were analysed for their mtDNA haplotypes. Nuclear DNA markers (microsatellites, LDH-C1* gene) were also included in genetic analyses since mtDNA is inherited only maternally. After statistical analyses, relations between individuals from the upper and lower Mrtvica River were reconstructed. Results. Using both LDH-C1* and seven microsatellite loci with several alleles exclusive to S. trutta, an introgression was detected only in the upper reaches of the Mrtvica River, where only stream-dwelling trout form occurs. In the lower reaches no introgression was detected at all, as revealed by the absence of both the Atlantic mitochondrial haplotype and microsatellite alleles exclusive to S. trutta. Conclusion. The allelic frequency at seven microsatellite loci of Salmo spp. from the two river sections revealed very different population structure, as a consequence of a low rate of gene flow between them. In addition to the physical barrier that prevents Salmo sp. from the lower Mrtvica River to migrate to the upper river section, it seems that the opportunity to mate with the large pool of conspecifics, including lake-dwelling S. farioides (i.e., Salmo cf. dentex), prevents Salmo trutta from surviving at the lower reach and spread to the rest of the Morača River and Lake Skadar systems.
The Freshwater Fish Invasiveness Screening Kit (FISK) v2 and Aquatic Species Invasiveness Screeni... more The Freshwater Fish Invasiveness Screening Kit (FISK) v2 and Aquatic Species Invasiveness Screening Kit (AS-ISK) risk identification screening tools were used to assess the invasiveness potential of 24 non-native (NNS) freshwater fish species in the River Neretva catchment (Bosnia and Herzegovina and Croatia), a risk assessment (RA) area that is an important Mediterranean hotspot for fish endemism. The two assessors assigned similar scores for the invasiveness potential of the NN fishes, and both screening tools successfully distinguished invasive from non-invasive species. Mean calibrated threshold scores were 10.25 for FISK and 10.00 for AS-ISK, with the latter increasing to 12.62 when questions that assess the likely impact of predicted future climate conditions on the RA were taken into consideration. These relatively low threshold values are characteristic of areas with an elevated number of translocated species and suggest that NN fishes pose a considerable threat to native species and ecosystems. FISK ranked 50.0-62.6% of the species as being of 'high risk' compared with 58.4-59.3% using AS-ISK. The highest scores ('very high risk') were attributed to gibel carp Carassius gibelio (Bloch, 1782) and pikeperch Sander lucioperca (Linnaeus, 1758). The generic screening tool for aquatic species (AS-ISK) provided similar risk rankings to its predecessor, FISK, as regards invasiveness potential. For this reason, it is likely to be an effective tool for evaluating the potential invasion risk of NNS freshwater fishes for other RA areas in the Balkans.
Recreational and professional fishermen often argue against each other. Therefore the aim of this... more Recreational and professional fishermen often argue against each other. Therefore the aim of this research was to compare the official data of both kinds of fishing on the Danube in the three neighbouring countries.
A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native... more A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native species risk assessments to inform management and control measures, with pre-screening tools, such as the Fish Invasiveness Screening Kit (FISK) providing a useful first step. Applied to 43 non-native and translocated freshwater fishes in four Balkan countries, FISK reliably discriminated between invasive and non-invasive species, with a calibration threshold value of 9.5 distinguishing between species of medium and high risk sensu lato of becoming invasive. Twelve of the 43 species were assessed by scientists from two or more Balkan countries, and the remaining 31 species by a single assessor. Using the 9.5 threshold, three species were classed as low risk, 10 as medium risk, and 30 as high risk, with the latter category comprised of 26 moderately high risk, three high risk, and one very high risk species. Confidence levels in the assessments were relatively constant for all species, i...
Risk assessment of the aquatic ecosystem of the River Jadar is based on the composition and amoun... more Risk assessment of the aquatic ecosystem of the River Jadar is based on the composition and amount of wastewater that is to be processed and released into the stream. This study aimed to assess the effects of untreated wastewater on aquatic ecosystem components, presumably fishes, by simulating the accident. Methodology relied exclusively on the published documents that investors, "Rio Tinto'' and "Rio Sava Exploration" d.o.o., issued about the boron and lithium mine in the Jadar region of Serbia as the only source of the publicly available data about concentration of mineral contents in underground water. Results revealed that concentrations of boron in a range of 3.43-12058.83 mg l-1 and those of lithium in a range of 0.70-2452.50 mg l-1 in a stream water of the River Jadar would pose a great risk to aquatic ecosystem in any lapse in proper processing of wastewater at either average low-, medium-, or high-water levels. Such high contents would inevitably cause toxic, genotoxic and other pathological effects on aquatic organisms. Records published on the relevant in vitro models reveal that if the concentration of boron and lithium in the stream water would exceed safe concentrations, the ecosystem would be seriously harmed, especially for the fish that are most sensitive to metal pollution. Due to a lack of actual referent in-field data, it is difficult to predict either the extent of harmful effects on downstream sections, or the period the ecosystem would need to recover from high levels of pollution.
Climate change that has occurred at the end of the last and at the beginning of this century, amo... more Climate change that has occurred at the end of the last and at the beginning of this century, among other things, has a certain impact on forests as well. For the territory of Eastern Serbia, for two periods of climate observations, the reference period 1961-1990 and the period 1991-2012, a comparative analysis of the following climatic elements was done: air temperature, amount of precipitation and relative humidity of air. Calculations were performed on the basis of collected and systematized data from 11 meteorological stations (6 synoptic/main climatological and 5 regular climatological) that were part of the Republic Hydrometeorological Service, situated in the area of Eastern Serbia. Analysis of the anomalies of air temperature and precipitation as indicators of climate change for the period 1991-2012 compared to the reference period 1961-1990 was done separately for each of the four seasons (winter, spring, summer, autumn) and summarized for each period. The results of the co...
Austropotamobius torrentium (Schrank, 1803) lives in two watercourses, namely Subotica (Sana) and... more Austropotamobius torrentium (Schrank, 1803) lives in two watercourses, namely Subotica (Sana) and Toplik (Tilava). The influence of the ecological conditions of these rivers on individuals of this species is analyzed based on 22 morphometric parameters. The assessment of abiotic conditions was done through the measurement of physical and chemical water parameters and the analysis of the composition of phytobenthos and macrozoobenthos. Sampling was carried out in June, September, and October 2021. Water quality at the investigated localities (on the basis of abiotic and biotic parameters) is oligo to betamesosaprobic. A total of 37 crayfish were analyzed (20 from Subotica and 17 from Toplik). Female crayfish have shown significant differences in the head width (HEW) and abdominal thickness (ABH). Males differed significantly in a number of parameters, including the weight (W), head shape (HEL and HEW), rostrum length (ROL), carapace width (CPW), and abdominal shape (ABH and ABL). Hig...
Huchen or Danube salmon Hucho hucho (Linnaeus 1758) is one of the largest salmonid species in the... more Huchen or Danube salmon Hucho hucho (Linnaeus 1758) is one of the largest salmonid species in the world and the largest species native to the Danube basin in Europe. In Serbia, this species inhabits the Drina river system, as well as the upper reaches of the River Ibar. It has already been introduced into the rivers Moravica and Đetinja, which are part of the Zapadna Morava catchment area. Most recently, huchen was stocked from its native habitat into the rivers Jerma and Nišava in the Južna Morava river system, and into the River Mlava which flows into the Danube. Huchen is listed as an endangered (EN) species on the IUCN Red List of Threatened Species and is protected in Serbia, and a Conservation Action Plan has already been adopted. In this report, we present the first record of this species in the River Grza, which is a part of the Velika Morava river system, outside its native range. The ichthyofauna of this recipient river consists of brown trout Salmo trutta L. and Eurasian minnow Phoxinus phoxinus L. In a small river of a fragile ecosystem such as this, the introduction of huchen as an apex predator can seriously harm the species of the native fish community, which warns of the illegal stocking measures currently in process.
Brown trout is a common type of fish grown for consumption in open and flowing fish ponds on the ... more Brown trout is a common type of fish grown for consumption in open and flowing fish ponds on the rivers of Bosnia and Herzegovina. We conducted this study during three seasons (spring, summer and autumn) to obtain a complete picture of the morphological and histological characteristics of selected trout tissues. The physicochemical characteristics of the water from the Pliva River near Pljeva and the fish pond where intensive breeding of trout is carried out were analyzed. These analyses have shown that there are no major deviations in water quality and that the water in the pond is of excellent quality. A total of 90 trout were harvested during all three seasons and their morphometric characteristics were determined by analyzing ten parameters. After the dissection of all individuals, histological and stereological analysis was performed to compare the tissues of the liver, stomach, gills and muscles. These analyses showed significant differences in the histoarchitecture of selected trout tissues from the pond compared to the river. Liver tissue had altered hepatocyte shape and presence of adipocytes; stomach tissue had stronger mucosa and weaker muscle layer; gill tissue had lower respiratory lamellae; while muscle tissue had a significant presence of adipose tissue in brown trout living in the fish pond compared to those in the river. All these changes are due to the quality of commercial feed and the inability to move freely.
The handbook of environmental chemistry, Sep 24, 2014
On the survey of the recent records, the fish and lamprey fauna of the River Sava catchment consi... more On the survey of the recent records, the fish and lamprey fauna of the River Sava catchment consists of 74 species, 15 of which being considered alien. The indigenous species diversity, explained using the relation N = 0. 546 A 0.232, fits well into the range common for large catchments in Europe. Both taxonomic and ecological diversity, as well as the character of fish communities in streams and rivers, are strongly correlated with the stream order. On the relative abundance of species in fish communities, the upper rhithron fish communities cluster distinctly from those belonging to the middle rhithron, within which several subgroups of fish communities were distinguishable. Fish communities of the middle rhithron character in streams and small rivers stand distinctly apart from those belonging to particular sections of large rivers (e.g., the Rivers Sava, Drina, Vrbas, and Bosna), with the transitional type of middle rhithron fish community in larger rivers (e.g., those in the Rivers Una and Sana) that resemble more to the fish communities common in middle rhithron streams. Fish communities in the middle section of the River Sava in Croatia and in the bordering area with Bosnia and Herzegovina mainly belong to the lower rhithron, attaining the character of potamon in the most downstream, Serbian section. River Sava’s fish communities strongly interact with the ones occurring in the most downstream sections of their largest tributaries, e.g., the Rivers Una, Vrbas, Bosna, Drina, and Kolubara, which makes them very similar in structure in the areas of river mouths. Classification of fish communities based solely on the presence and absence of species revealed similar general pattern of fish community classification, though with the more sharp delimitation between those belonging to the upper and middle rhithron on one and to the lower rhithron and potamon on the other side. That was supported by the determination of fish communities belonging to the upper rhithron with brown trout Salmo cf. trutta, European bullhead Cottus gobio, and minnow Phoxinus phoxinus as the most common fish species. Fish communities belonging to the middle rhithron were determined mainly with chub Squalius cephalus and spirlin Alburnoides bipunctatus, whereas brook barbel Barbus balcanicus and stone loach Barbatula barbatula occurred in both upper rhithron and middle rhithron. Nase Chondrostoma nasus were associated with both middle and lower rhithron fish communities. The most common fish species that determine the lower rhithron fish communities were common bream Abramis brama, ide Idus idus, and bleak Alburnus alburnus, with the northern pike Esox lucius, Balon’s ruffe Gymnocephalus baloni, and racer goby Neogobius gymnotrachelus as significant species explaining fish communities of both lower rhithron and potamon. The level of production of fish in the River Sava varies remarkably within the sections with the similar ecological features, as well as between the sections that differ for the type of fish community. The greatest biomass and annual natural production were recorded in the sections homing the potamon and lower rhithron fish communities, especially in the flooding areas of side arms and oxbows which serve as spawning areas and nurseries. A total of 15 alien fish species was recorded in the River Sava catchment, the Prussian carp Carassius gibelio and brown bullhead Ameiurus nebulosus being assessed the most invasive in the areas with the potamon fish community. A strong impact from both long-term and recent stocking with alien hatchery-reared brown trout strains and rainbow trout in the upper rhithron fish communities was recently recognized. Mudminnow Umbra krameri and huchen (or Danube salmon) Hucho hucho are considered the two most threatened fish species of the River Sava catchment, where various types of riverbed modifications, especially the damming, were seen the most prominent threatening factors for fish diversity.
Amazon sailfin catfish Pterygoplichthys pardalis (Castelnau, 1855) (Loricariidae, Siluriformes) i... more Amazon sailfin catfish Pterygoplichthys pardalis (Castelnau, 1855) (Loricariidae, Siluriformes) is a new non-indigenous fish species recorded in the Serbian section of the Danube River, being reported for the first time in inland waters of Europe, as well. A single, female fish was ripe and in good shape, although considering its original neotropical dispersal area and recording of occurrence in summer, with the only single female individual, its acclimatization is not likely. However, both its estimated invasive potential after the FISK protocol scoring of 26 and the risk of its introduction and establishment in the recipient area in concern after the IFRA protocol scoring of 61 should be considered moderate. That, together with the invasive history of this sailfin catfish and its congeners in southeastern Asia and Meso-American region imposes a need for precaution.
Abstratct⎯The part of the River Danube basin in the Western Balkans region (11 sampled localities... more Abstratct⎯The part of the River Danube basin in the Western Balkans region (11 sampled localities and 57 in total with using of published data) revealed the remarkable diversity of brown trout assessed using the Control Region (CR) of mitochondrial DNA (mtDNA) as a molecular marker. The greatest number of brown trout populations holds brown trout of the Da1 haplotype. Particular distinct haplotypes are limited to isolated brown trout stocks. There are haplotypes of Danubian (Da), and those of Atlantic (At), Adriatic (Ad) and marmoratus (MA) lineages introduced there. Phylogenetic relationships inferred between them implicate the plesiomorhic character of Da*Vr, Da*Dž and Da-s6 haplotypes that were resolved as ancestral clades, with the intermediate position between clades holding haplotypes of the non-Danubian lineage and more advanced haplotypes of the Danubian lineage. A uniform rate of evolution was found for all clades. The recent widespread distribution and exclusivity of Da1 haplotype imply its ancestral character among advanced Danubian haplotypes. Populations in the Sava, Drava, Una and Drina revealed an expansion, whereas those in the Kupa and Zapadna Morava catchments revealed both stability in size and great differentiation. Gene flow between stocks was found to be negligible.
In the sample of 83 specimens of the perch (Perca fluviatilis L., 1758), caught on eight differen... more In the sample of 83 specimens of the perch (Perca fluviatilis L., 1758), caught on eight different sampling sites at the Vlasinsko Lake reservoir, in April-October 1993, 25 infested specimens were found. They were infested with the following species of parasitic ciliates: Trichodinella epizootica, Apiosoma robustum, Apiosoma piscicolum ssp. perci, Ichthyophthirius multifiliis, Chilodonella cyprini and Chilodonella hexasticha. The most intensive infestation with all quoted parasitic ciliates was registered in April. Only Ichthyophthirius multifiliis infested the perch intensively in July. Trichodinella epizootica and Apiosoma robustum revealed both the highest prevalence and intensity of infestation. Regarding the localization of the parasitic species, Trichodinella epizootica and Apiosoma robustum had a much stronger affinity for the gills than for the skin of the perch. studied in Yugoslavia, although they are the commonest parasites of the freshwater fish. In Vlasinsko Lake reservoir l6 fish species have been registered to date, the most numerous of which are Perca fluviatilis and Carassius auratus gibelio. 2. Material and methods 2.1. Locality description The Lake Vlasinsko is a reservoir, 12 km in length and of average width of 1 km (maximal width of 2.5 km). It is situated in the Southeastern Serbia, near the Bulgarian border, at 1 200 m above the sea level (42˚40′-42˚45′N, 22˚19′-22˚21′E).
A pool of data already existing about D-loop, i.e., the Control Region (CR) haplotypes of the mit... more A pool of data already existing about D-loop, i.e., the Control Region (CR) haplotypes of the mitochondrial DNA (mtDNA) of brown trout, Salmo trutta Linnaeus, 1758, tentative Adriatic trout Salmo farioides Karaman, 1938, and tentative Macedonian trout, Salmo macedonicus (Karaman, 1924), and their reconstructed phylogeography makes a good starting point for resolving their evolutionary history. That includes the dating of particular events in it. The events have hitherto been dated using the method of a molecular clock. Various calibrations were applied for the mutation rate, owing to the incongruence between the time of divergence that various authors notified and general knowledge about events in geological history and the periods in which they occurred in the Mediterranean region. Since geological history events were mandatory for setting the scene for the evolutionary history of brown trout, the incongruence between them has questioned the molecular clock calibration’s validity. ...
Salmonids are an extensively hatchery-reared group of fishes that have been introduced worldwide ... more Salmonids are an extensively hatchery-reared group of fishes that have been introduced worldwide mainly for their high commercial and recreational value. The Balkan Peninsula (south-eastern Europe) is characterised by an outstanding salmonid diversity that has become threatened by the introduction of non-native salmonids whose potential risk of invasiveness in the region remains unknown and especially so under predicted climate change conditions. In this study, 13 extant and four horizon non-native salmonid species were screened for their risk of invasiveness in the Danube and Adriatic basins of four Balkan countries. Overall, six (35%) of the screened species were ranked as carrying a high risk of invasiveness under current climate conditions, whereas under predicted conditions of global warming, this number decreased to three (17%). Under current climate conditions, the very high risk (‘top invasive’) species were rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta (sen...
An old male ship sturgeon Acipenser nudiventris caught in the middle Danube River at the river km... more An old male ship sturgeon Acipenser nudiventris caught in the middle Danube River at the river km 1390 near Apatin, Serbia is the first reliable record of the species since 1989 in the whole river basin.
Over the last 14 years, ichthyological and ecological parameters have been monitored in the Labud... more Over the last 14 years, ichthyological and ecological parameters have been monitored in the Labudovo okno Ramsar site. This area is important for its biodiversity as it is home to many rare and endangered plants and animal species. A total of 3861 fish specimens were sampled and measured at six sampling sites four times during the sampling period. An analysis of biodiversity indexes, relative biomass (kg/ha), and relative annual production (kg/ha) was carried out to assess the effectiveness of existing conservation measures. The results obtained show a trend decline in biodiversity, relative biomass, and relative annual production. This indicates a biodiversity conservation problem that should be addressed through other mechanisms in addition to the principles of the Ramsar Convention.
Small run‐of‐river hydropower plants (RRHPs) have revealed strong harmful effects worldwide on st... more Small run‐of‐river hydropower plants (RRHPs) have revealed strong harmful effects worldwide on stream habitats (e.g., fragmentation and destruction) and decreased fish species, especially anadromous species abundance. Recently, RRHPs have rapidly been installed in Serbia. Most were installed on montane streams because their steep slopes are most convenient for hydropower energy production at minimal costs. Brown trout Salmo trutta are prominent in the fish communities of this rarest type of aquatic ecosystems. Their native molecular diversity reflects a biodiversity hotspot in the Balkans, and they provide attractive fishing opportunities. Records from fishery management plans for highland stream fisheries where RRHPs were installed revealed reduced brown trout biomass compared with streams without RRHPs. Research on six streams with operational RRHPs revealed severe deterioration of habitat, for example, increased water temperature, reduced dissolved oxygen, and increased nutrient contents. Effects on fish communities were evident from a change in their structure. Resident, stream‐dwelling brown trout were the most affected species with steep declines in abundance, biomass, and productivity. Fragmentation owing to damming was also reflected by deterioration of their age structure. Unique native brown trout stocks susceptible to adverse effects are difficult to restore by stocking, and fish passages commonly supplied as compensation to overcome the disruption of habitats cannot mitigate the threat posed to the fish.
Background. The diversity of wild trout stocks in Montenegro is compromised by insufficiently con... more Background. The diversity of wild trout stocks in Montenegro is compromised by insufficiently controlled stocking. Adriatic and Mediterranean areas show a high degree of endemism of the salmonid species, with numerous native Salmo taxa described. The invasive effect of brown trout, Salmo trutta Linnaeus, 1758, of the Atlantic haplogroup on the endemic Adriatic trout, Salmo farioides Karaman, 1938, in the drainage area of the Adriatic Sea basin is lower compared to the effect inflicted by S. trutta has on Salmo labrax Pallas, 1814 of the Danubian haplogroup. The presently reported study was intended to describe the genetic structure of the population of Adriatic trout, Salmo farioides, from the Mrtvica River, a right tributary of the Morača River, Montenegro, in order to get an insight into the spread of non-native strains and their introgression into the native Adriatic trout gene pool. Material and methods. Trout specimens sampled from the lower section of the Mrtvica River from 2004 to 2007, and from its upper section in the spring of 2014, were analysed for their mtDNA haplotypes. Nuclear DNA markers (microsatellites, LDH-C1* gene) were also included in genetic analyses since mtDNA is inherited only maternally. After statistical analyses, relations between individuals from the upper and lower Mrtvica River were reconstructed. Results. Using both LDH-C1* and seven microsatellite loci with several alleles exclusive to S. trutta, an introgression was detected only in the upper reaches of the Mrtvica River, where only stream-dwelling trout form occurs. In the lower reaches no introgression was detected at all, as revealed by the absence of both the Atlantic mitochondrial haplotype and microsatellite alleles exclusive to S. trutta. Conclusion. The allelic frequency at seven microsatellite loci of Salmo spp. from the two river sections revealed very different population structure, as a consequence of a low rate of gene flow between them. In addition to the physical barrier that prevents Salmo sp. from the lower Mrtvica River to migrate to the upper river section, it seems that the opportunity to mate with the large pool of conspecifics, including lake-dwelling S. farioides (i.e., Salmo cf. dentex), prevents Salmo trutta from surviving at the lower reach and spread to the rest of the Morača River and Lake Skadar systems.
The Freshwater Fish Invasiveness Screening Kit (FISK) v2 and Aquatic Species Invasiveness Screeni... more The Freshwater Fish Invasiveness Screening Kit (FISK) v2 and Aquatic Species Invasiveness Screening Kit (AS-ISK) risk identification screening tools were used to assess the invasiveness potential of 24 non-native (NNS) freshwater fish species in the River Neretva catchment (Bosnia and Herzegovina and Croatia), a risk assessment (RA) area that is an important Mediterranean hotspot for fish endemism. The two assessors assigned similar scores for the invasiveness potential of the NN fishes, and both screening tools successfully distinguished invasive from non-invasive species. Mean calibrated threshold scores were 10.25 for FISK and 10.00 for AS-ISK, with the latter increasing to 12.62 when questions that assess the likely impact of predicted future climate conditions on the RA were taken into consideration. These relatively low threshold values are characteristic of areas with an elevated number of translocated species and suggest that NN fishes pose a considerable threat to native species and ecosystems. FISK ranked 50.0-62.6% of the species as being of 'high risk' compared with 58.4-59.3% using AS-ISK. The highest scores ('very high risk') were attributed to gibel carp Carassius gibelio (Bloch, 1782) and pikeperch Sander lucioperca (Linnaeus, 1758). The generic screening tool for aquatic species (AS-ISK) provided similar risk rankings to its predecessor, FISK, as regards invasiveness potential. For this reason, it is likely to be an effective tool for evaluating the potential invasion risk of NNS freshwater fishes for other RA areas in the Balkans.
Recreational and professional fishermen often argue against each other. Therefore the aim of this... more Recreational and professional fishermen often argue against each other. Therefore the aim of this research was to compare the official data of both kinds of fishing on the Danube in the three neighbouring countries.
A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native... more A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native species risk assessments to inform management and control measures, with pre-screening tools, such as the Fish Invasiveness Screening Kit (FISK) providing a useful first step. Applied to 43 non-native and translocated freshwater fishes in four Balkan countries, FISK reliably discriminated between invasive and non-invasive species, with a calibration threshold value of 9.5 distinguishing between species of medium and high risk sensu lato of becoming invasive. Twelve of the 43 species were assessed by scientists from two or more Balkan countries, and the remaining 31 species by a single assessor. Using the 9.5 threshold, three species were classed as low risk, 10 as medium risk, and 30 as high risk, with the latter category comprised of 26 moderately high risk, three high risk, and one very high risk species. Confidence levels in the assessments were relatively constant for all species, i...
On the survey of the recent records, the fish and lamprey fauna of the River Sava catchment consi... more On the survey of the recent records, the fish and lamprey fauna of the River Sava catchment consists of 74 species, 15 of which being considered alien. The indigenous species diversity, explained using the relation N = 0. 546 A0.232, fits well into the range common for large catchments in the Europe. Both taxonomic and ecological diversity, as well as the character of fish communities in streams and rivers are strongly correlated with the stream order. On the relative abundance of species in fish communities, the upper rithron fish communities cluster distinctly from those belonging to the middle rithron, within which several sub-groups of fish communities were distinguishable. Streams and small rivers of fish communities of the middle rithron character stand distinctly apart from those belonging to particular sections of large rivers (e.g., the Rivers Sava, Drina, Vrbas and Bosna), with the transitional type of middle rithron fish community in larger rivers (e.g., those in the Rivers Una and Sana) that resemble more to the fish communities common for middle rithron streams. Fish communities in the middle section of the River Sava in Croatia and in the bordering area with the Bosnia and Herzegovina mainly belong to the lower rithron, attaining the character of potamon in the most downstream, Serbian section. River Sava’s fish communities strongly interact with the ones occurring in the most downstream sections of their largest tributaries, e.g., the Rivers Una, Vrbas, Bosna, Drina and Kolubara, which makes them very similar in structure in the areas of river mouths. Classification of fish communities based solely on the presence and absence of species revealed similar general pat-tern of fish communities classification, though with the more sharp delimitation between those belonging to the upper and middle rithron on one, and to the lower rithron and potamon on the other side. That was supported by determination of fish communities belonging to the upper rithron with brown trout Salmo cf. trutta, European bullhead Cottus gobio and minnow Phoxinus phoxinus as the most common fish species. Fish communities belonging to the middle rithron were de-termined mainly with chub Squalius cephalus and spirlin Alburnoides bipunctatus, whereas brook barbel Barbus balcanicus and stone loach Barbatula barbatula occurred in both upper and middle rithron. Nase Chondrostoma nasus were associated with both middle and lower rithron fish communities. The most common fish species that determine the lower rithron fish communities were common bream Abramis brama, ide Idus idus and bleak Alburnus alburnus, with the northern pike Esox lucius, Balon’s ruffe Gymnocephalus baloni and racer goby Neogobius gymnotrachelus as significant species explaining fish communities of both lower rithron and potamon. The level of production of fish in the River Sava varies remarkably within the sections with the similar ecological features, as well as between the sections that differ for the type of fish community. The greatest biomass and annual natural production were recorded in the sections homing the potamon and lower rithron fish communities, especially in the flooding areas of side arms and oxbows which serve as spawning areas and nurseries. A total of 15 alien fish species was recorded in the River Sava catchment, the Prussian carp Carassius gibelio and brown bullhead Ameiurus nebulosus being assessed the most invasive in the areas with the potamon fish community. A strong impact from the both long-term and recent stocking with alien hatchery reared brown trout strains and rainbow trout in upper rithron fish communities was recently recognized. Mudminnow Umbra krameri and huchen (or Danube salmon) Hucho hucho are considered the two most threatened fish species of the River Sava catchment, where various types of river bed modifications, especially the damming, were seen the most prominent threatening factors for fish diversity.
Proceedings of the Wild Trout XII Symposium "Who's Driving and Where are We Going?", 2017
Native Brown Trout Salmo trutta reveal remarkable diversity in Serbia, with eight exclusive and a... more Native Brown Trout Salmo trutta reveal remarkable diversity in Serbia, with eight exclusive and a couple of more widely spread mtDNA haplotypes. Insufficiently controlled stocking is a main threat to that, as well as to the amenity value of wild Brown Trout. Native or wild Brown Trout stocks deteriorated as a consequence of stocking with inappropriate strains. Three nonnative trout species and three Brown Trout strains stocked into streams of Serbia were classified as medium-high to high risk of being invasive. Alien Brown Trout strains crossbreed with, and incorporate into the native Brown Trout stocks. Fly fishermen in Serbia greatly differ in attitudes towards fishery policy, management, and conservation of native Brown Trout stocks. They are opposed to conservation measures that may affect angling quality. Though declaratively being conservation-friendly, the majority of anglers consider stocking more efficient than Catch-and-Release (C&R) regulations. Despite good conservational and fishery effects of C&R, increases in license sales from fishermen presses trout farmers and fishery managers to stock, regardless of adverse effects on native Brown Trout stocks. Subsidiaries to farmers and grants awarded to fishery managers could promote stocking of native strains and conservation of native stocks.
Book of Abstracts of the Wild Trout XII Symposium "Science, Politics and Wild Trout management: Who's Driving and Where are We Going?", 2017
Native brown trout Salmo cf. trutta reveal remarkable diversity in Serbia, with eight exclusive a... more Native brown trout Salmo cf. trutta reveal remarkable diversity in Serbia, with eight exclusive and a couple of more widely spread mtDNA haplotypes. Insufficiently controlled stocking is a main threat to that, as well as to the amenity value of wild brown trout. Native or wild brown trout stocks deteriorated as a consequence of stocking with inappropriate stocking material. Three of non-native trout species and three brown trout strains stocked into streams of Serbia were classified as medium-high to high risk of being invasive. Alien brown trout strains cross breed with, and incorporate into the native brown trout stocks. Fly fishermen in Serbia greatly differ in attitudes towards fishery policy, management and conservation of native brown trout stocks. They are opposed in tolerance toward the impact of conservational demands on the quality of fishing. Though declaratively being conservation-friendly, majority acts as considering stocking more efficient than Catch-and-Release (C&R). Despite a good conservational and fishery effects of C&R, increase in incomes from fishermen presses trout farmers and fishery managers to stock, regardless of adverse effects on native brown trout stocks. Subsidiaries to farmers and grants awarded to fishery managers could promote use of native stocking material and conservation of native stocks
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