Fishing district boundaries: Potok Okna od ústia do VN Vyšná Rybnica po ústie potoka Barlahov. The score, the best window of the day and what pushes it up or down Loading data… Water level, temperature, modelled flow and gradient Remetské Hámre – Okna · level stable The level is measured at an SHMÚ gauge; it is not the depth of the water in the fishing district. Loading data… Fast watercourse Podhorský potok: fast water, stony bottom, riffles and the pools below them. Typical trout waters. Hour by hour, pressure and the next few days Loading data… Where the sun and moon are right now and when the best windows of the day will come Drag along the axis to see where the sun and moon will be. The day lasts 9 h 29 min. Full moon around 24 Nov, new moon around 9 Nov. Solunar theory is not scientifically confirmed; we treat it as a supplement. The golden hour is the time around sunrise and sunset, when fish often bite. Course of the water, spots along the water, character and basic data The line shows the course of the fishing district according to the "Rybárske revíry" data 2026. Verify access points and exact boundaries on site. Closed season, fishing hours, minimum sizes and daily limit. For guidance only: check them in the fishing regulations of the fishing district 1 Oct – 15 Apr fishing for all fish prohibitedoutside this period Exception: on waters where huchen occurs, from 1 Nov to 31 Dec fishing for huchen is possible only with a huchen fishing permit (§ 13, para. 4 and § 19 of the Act). The protection periods by species (below) apply independently of this closed season. Applies only outside the closed season. Outside these hours fishing is prohibited (§ 14(b) of the Act). April, September6.00 – 20.00 h May, August5.00 – 21.00 h June, July4.00 – 22.00 h November, December7.00 – 19.00 h Months missing from the table fall within the closed season. The hours in November and December on trout and grayling waters relate to the exception for fishing huchen (§ 13, para. 4 of the Act); check in the fishing regulations what may be caught at that time. On border waters the hours in the permit or the fishing regulations apply (§ 11, para. 2 of the Decree). The Act regulates night fishing in two wordings that seem to contradict each other at first sight, so always ask about it in the fishing regulations of the district or the fishing guard. This is a summary. For baits, hooks and groundbait also read the fishing regulations of the district, because the user may tighten the conditions. The blue and green groups cannot be combined. The limit applies per day, also when fishing in several districts, and once it is reached, fishing for that day ends. The species groups follow the SRZ interpretation of January 2026, not the text of the section directly. The district user may set a lower limit in the permit, in which case the stricter one applies. During this period the species must not be caught, even if the water type otherwise allows fishing at that time. It applies independently of the closed season for all fish. Some species are protected all year round (for example zingel and streber, lampreys, gudgeons, spined loaches, maraena whitefish, Carpathian barbel, sabre carp) and fishing for them is always prohibited. The full list of species is in the guide The fishing law, rule by rule. The shortest length from which you may keep a fish. The district user may raise the size, so look for the valid value in the permit and the fishing regulations. Total length is measured from the front of the head to the end of the longest ray of the tail fin (§ 12, para. 4). No minimum size applies, for example, to sunbleak, Prussian carp, European perch, roach, stone loach and invasive species. As of 6 Nov 2026: Act no. 216/2018 Coll. on fisheries (wording effective 1 Jan 2022) and Decree no. 381/2018 Coll. (wording effective 1 Jan 2019); we found no newer wording. The law may change; you can find the current wording on Slov-Lex (Act) and Slov-Lex (Decree). On the same stream and nearest in the basin Loading the 3D terrain model… Water quality, river basin, bottom, fish, aquatic insects, wildlife and hazards from open databases. Except for wildlife and hazards, they are also included in the activity score. The water is in the bottom 23% of 461 trout fishing districts with data. Reliability high: we used 7 water data points. gradient 24 ‰, 309 m a.s.l. → grayling zone Based on gradient and elevation, the stream lies in an area that corresponds to the grayling zone. This is a natural zone for trout. European streams are divided from source to mouth into zones with typical fish: trout, grayling, barbel and lowland; they are determined mainly by gradient and stream size (Huet 1959), and the zones can also be used to assess the condition of streams (Aarts and Nienhuis 2003). We estimate the zone from the gradient of the fishing district's line and its elevation; it is a simplification without stream width. A match between the zone and the fishing district type adds +1 to quality, a clear mismatch −1. Sources: Huet 1959; Aarts and Nienhuis 2003 ≈ 2.4 °dH (0.4 mmol/l of calcium and magnesium), ŠGÚDŠ atlas Soft water is poor in minerals and nutrients: there is usually less food, the water is more sensitive to acidification, and metals are more toxic in it. Water with calcium and magnesium is more productive and buffers acidity swings better: trout production was higher in calcareous hard waters (Almodóvar et al. 2006), and an index based on dissolved solids and depth predicts fish yield from lakes (Ryder et al. 1974). In Irish streams, however, geology did not change trout density (Lehane et al. 2004), and Downing et al. (1990) showed that production is related rather to primary production. Hence only ±1 point. Hardness comes from the ŠGÚDŠ atlas, not from a measurement in the fishing district; it replaces the separately assessed bedrock of the basin. Sources: Almodóvar et al. 2006; Lehane et al. 2004; Ryder et al. 1974 pH 7.7, EEA measurement The pH is within the range in which fish commonly thrive. Below about pH 6 fish suffer, and trout and grayling are more sensitive than cyprinids (Alabaster and Lloyd 1982); in acidic soft water, aluminium is released from the soil and damages gills (Gensemer and Playle 1999). The pH from the atlas is a model estimate, so the reduction is only −1 or −2, and only where we have no pH measurement (which is assessed by a separate factor). Sources: Alabaster and Lloyd 1982; Gensemer and Playle 1999 10.9 mg/l, EEA station The water is very well oxygenated. Oxygen is limiting for fish, and warmer water physically holds less of it (Benson and Krause 1984). An overview of the oxygen requirements of aquatic animals is in Davis (1975); the specific thresholds of 5, 7 and 9 mg/l are our simplification. Sources: Davis 1975; Benson and Krause 1984 ≈ 115 mg/l, from EEA conductivity Medium mineralisation corresponds to productive streams and reservoirs. Dissolved solids (mineralisation) are related to the fertility of the water, which is why Ryder used them to estimate fish production in lakes (Ryder 1965, Ryder et al. 1974). Downing et al. (1990) showed, however, that primary production is a better predictor of production. It does not enter the score, only the suitability index. Sources: Ryder 1965; Ryder et al. 1974; Downing et al. 1990 nitrate 1.0 mg N/l, phosphorus 0.02 mg P/l, EEA station A medium nutrient supply gives a good food base without a marked risk of algae. Fish production is related to the primary production of the water (Downing et al. 1990), and in Czech fishing districts the abundance of perch grew with ecosystem productivity (Lyach and Remr 2019). Too many nutrients, however, lead in summer to algal blooms and oxygen swings (Paerl and Huisman 2008). Sources: Downing et al. 1990; Lyach and Remr 2019; Paerl and Huisman 2008 1 elements among the highest 10 % in Slovakia (ŠGÚDŠ atlas 1999) Metals in sediment can accumulate in benthic animals and fish; high values are often natural in ore areas. In soft water metals are more toxic, so we rate more strictly. The toxicity of metals to fish decreases with water hardness, because calcium competes with the metal for sites on the gills (Pagenkopf 1983). The ŠGÚDŠ atlas gives only the rank among streams, not a concentration comparable with a limit (MacDonald et al. 2000). In hard water we therefore rate metals more leniently, in soft water more strictly. Sources: Pagenkopf 1983; Gensemer and Playle 1999; MacDonald et al. 2000 The same water data evaluated against the requirements of trout, grayling and carp. The fishing district is registered as a trout district; its type is highlighted. The index 0 to 100 compares the properties of the water with the requirements of the species (60 is the neutral value, 100 the ideal). The verbal rating comes from comparison with other fishing districts of the same type, because most Slovak waters have good values for their species. The index does not affect whether fish really occur in the fishing district (that is decided by stocking and the manager). Hardness, pH and mineralisation from the atlases are historical and model estimates. Only a small part of this feeds into the conditions score and fishing district quality (hardness ±1, atlas acidity −2 to 0, stream zone match ±1 to quality). We assessed 18 factors; 5 of them change the score. The adjustments range from −14 to +12 points so that they do not outweigh the weather and water temperature. They are counted in the score, in the ranking and in the filters. 10.9 mg/l, EEA station 0.0 km from the water, 2008 The water is excellently oxygenated; fish stay active even at a higher temperature. The analysis is from 2008, so it is counted at 50%. Oxygen is limiting for fish, and warmer water physically holds less of it (Benson and Krause 1984). An overview of the oxygen requirements of aquatic animals is in Davis (1975); the specific thresholds of 5, 7 and 9 mg/l are our simplification. Sources: Davis 1975; Benson and Krause 1984 nitrates 1.0 mg N/l, phosphorus 0.02 mg P/l, EEA station 0.0 km from the water, 2008 A medium nutrient supply gives a rich food base without a significant risk of algae. The analysis is from 2008, so it is counted at 50%. Fish production is related to the primary production of the water (Downing et al. 1990), and in Czech fishing districts the abundance of perch grew with ecosystem productivity (Lyach and Remr 2019). Too many nutrients, however, lead in summer to algal blooms and oxygen swings (Paerl and Huisman 2008). Sources: Downing et al. 1990; Lyach and Remr 2019; Paerl and Huisman 2008 ≈ 2.4 °dH, ŠGÚDŠ atlas Very soft water is poor in minerals and nutrients: there is usually less food and the fish grow more slowly. Water with calcium and magnesium is more productive and buffers acidity swings better: trout production was higher in calcareous hard waters (Almodóvar et al. 2006), and an index based on dissolved solids and depth predicts fish yield from lakes (Ryder et al. 1974). In Irish streams, however, geology did not change trout density (Lehane et al. 2004), and Downing et al. (1990) showed that production is related rather to primary production. Hence only ±1 point. Hardness comes from the ŠGÚDŠ atlas, not from a measurement in the fishing district; it replaces the separately assessed bedrock of the basin. Sources: Almodóvar et al. 2006; Lehane et al. 2004; Ryder et al. 1974 ammonium 0.33 mg N/l, EEA station 0.0 km from the water, 2008 Elevated ammonium: at a higher pH and temperature it releases ammonia, which is harmful to the gills; trout and grayling are more sensitive to it. The analysis is from 2008, so it is counted at 50%. Part of the ammonium is converted, depending on pH and temperature, to ammonia, which damages the gills (Emerson et al. 1975). The repealed Directive 2006/44/EC gave very low values as guidance (0.04 mg/l ammonium for salmonid waters, 0.2 mg/l for cyprinid waters). Our thresholds are milder (above 0.6 mg N/l for cyprinid and other waters, above 0.2 mg N/l for trout and grayling waters), because this is an annual average from a nearby station, not a value at the fishing spot. Sources: Emerson et al. 1975; Directive 2006/44/EC Clays and loams, ŠGÚDŠ A fine-grained bottom is not typical of trout waters; the water clouds more easily. Trout production is higher in limestone hard waters (Almodóvar et al. 2006), but in Irish streams geology did not change trout density and the structure of the channel decided (Lehane et al. 2004). The evidence diverges; the weight is small. Sources: Almodóvar et al. 2006; Lehane et al. 2004 Data for these factors is missing or within the normal range: The rules are indicative and based on fishing practice and scientific studies; for each factor you can see how well it is supported. Weather, air pressure and water temperature affect the score more than this data does. Fish have enough oxygen even at a higher temperature. The usual range in which fish live without problems. A good food base without a great risk of algae. Nutrient-poor water with few algae. It may be the effect of wastewater or agriculture. Typical of most Slovak watercourses. Measured at station REMETSKE HAMRE (OKNA), 0.0 km from the water, the station has the same watercourse name. The data are from official monitoring, not from a measurement directly at the fishing district. This is an average over recent years, so the current state may differ. In the yearbooks for 2022 to 2025 this site has no unmet indicator. The location of the site is only approximate (based on the water body), so the actual sampling point may be elsewhere on the watercourse. The data comes from the SHMÚ yearbooks (surface waters 2022 to 2025). The yearbook lists the sites that failed the standard; a site missing from the yearbook is not considered clean. We determine the distance and the match of the watercourse name ourselves, so the assignment is indicative. Last exceeded in 2023: Last exceeded in 2023: Exceeded in 2025: Last exceeded in 2024: Exceeded in 2025: Exceeded in 2025: Exceeded in 2025: In the yearbooks 2017 to 2025 no exceedance of the standard is recorded at the station. Groundwater reaches streams as base flow, so the connection to the stream at the fishing district is only indirect. Natural substances (iron, manganese, sulfates, conductivity) are not counted in the yearbook-based assessment. The data comes from the SHMÚ yearbooks (groundwater 2017 to 2025). Watercourse from the HydroRIVERS database matched with the fishing district, line deviation about 83 m The data come from a global database with a coarser resolution (tens of metres), so they are only approximate for small waters. Depth and volume are model averages. After rain the water quickly turns turbid and fish hunt more by smell. Springs and groundwater outflows bring cooler water into the watercourse in summer and warmer in winter; fish stay near them in extreme weather. According to the geological map: fluviálne sedimenty: litofaciálne nečlenené nivné hliny, alebo piesčité až štrkovité hliny dolinných nív a nív horských potokov, holocén The map shows the bedrock geology, not the exact bottom at the spot. The actual bottom material may differ, especially where sediment has been deposited. A typical value from 8 groundwater stations within 10 km of the fishing district (nearest 3 km), measured in 2025. Closer stations carry more weight. This is groundwater near the district, not a measurement in the watercourse itself. The standard is the limit that SHMÚ gives for the indicator (for drinking water); a value equal to the standard counts as an exceedance, as it does at SHMÚ. The label "somewhere above the standard" means that the typical value is below the standard but at least one station exceeds it; which one is shown on the tile. Fish are more sensitive to some substances than people are. 0.005mg/l far below the standard Standard 0.5 mg/l. Range 0.005 to 0.04 mg/l, 8 stations. 0.005mg/l far below the standard Standard 0.5 mg/l. Range 0.005 to 0.2 mg/l, 8 stations. 5.7mg/l far below the standard Standard 50 mg/l. Range 0.5 to 37.3 mg/l, 8 stations. 3.57mg/l less oxygen Mark on the dial: 9 mg/l, the guideline for salmonid waters. Range 0 to 7.68 mg/l, 8 stations. 12.6°C warmer Range 9.8 to 14.4 °C, 8 stations. 6.95 suitable for fish Range 6.73 to 7.53, 8 stations. 1.33mmol/l soft Range 0.96 to 5.07 mmol/l, 8 stations. 0.018mg/l above the standard somewhere Standard 0.2 mg/l. Range 0.001 to 2.6 mg/l, 8 stations. Above the standard: 1 of 8 (Jovsa, 7.2 km from the fishing district). 0.004mg/l above the standard somewhere Standard 0.05 mg/l. Range 0.001 to 0.36 mg/l, 8 stations. Above the standard: 3 of 8 (highest: Ubrez, 6.4 km from the fishing district). 15.6mg/l above the standard somewhere Standard 250 mg/l. Range 0.5 to 325 mg/l, 8 stations. Above the standard: 1 of 8 (Chonkovce, 7.5 km from the fishing district). 18.7mg/l far below the standard Standard 250 mg/l. Range 1 to 116 mg/l, 8 stations. 33.3mS/m above the standard somewhere Standard 125 mS/m. Range 20.3 to 131 mS/m, 8 stations. Above the standard: 1 of 8 (Chonkovce, 7.5 km from the fishing district). 16% of standard below the standard Highest: Aluminium 0.16 mg/l (80% of the standard, 6.4 km from the fishing district). 8 stations. 30% of standard below the standard Highest: MCPB 0.03 µg/l (30% of the standard, 3 km from the fishing district). 2 stations. 0% of standard not detected Below the limit of quantification: substances from this group were not detected in the samples. 4 stations. 0% of standard not detected Below the limit of quantification: substances from this group were not detected in the samples. 4 stations. Sources Species that have been observed or recorded around the water. Wildlife, plants and hazards do not enter the fishing conditions score and are for information only. The name of a species leads to its page. The most common duck; it nests by almost every water with bankside vegetation. It stands in the shallows and lies in wait for small fish. It is easy to see along the banks of ponds and slow streams. A large white heron that hunts fish and frogs in the shallows. In Slovakia its numbers are rising, and in winter it can also be seen by watercourses. A large white waterbird that nests by slow waters, reservoirs and ponds with vegetation. The most common gull by the water. Nests in colonies at ponds and large reservoirs and also stays along rivers. An insect with aquatic larvae. Adults live only briefly and hatch all at once in swarms. Predatory insect. The larvae live underwater for several months to years; adult dragonflies hunt in the air above the water. Black with yellow spots. Lives in deciduous forests by clean mountain streams; the larvae develop in the stream. A harmless snake with two yellow spots on the nape. It swims well and hunts frogs, fish and newts. The largest native toad. In spring it migrates to water, where it breeds. A herbivore that changes the stream and its banks with dams and burrows. It is protected. It creates shallows and pools where fish and insects thrive. At dusk it flies just above the surface and hunts aquatic insects, mainly midges and mayflies. An invasive herb from East Asia that forms dense stands up to three metres tall. An invasive plant from the Himalayas, up to two metres tall, with pink flowers. It overgrows the banks of watercourses. A riparian tree whose roots reach below the water surface. A tall wetland plant with yellow flowers that grows on damp banks. Tall grass that forms extensive reed beds around ponds and on banks. An aquatic plant with yellow flowers and floating and submerged leaves. It grows in both standing and slow-flowing waters. They breed in standing water, so they are worst around reservoirs, oxbow lakes and floodplain forests, especially at sunset. How to protect yourself: When fishing in the evening and at night wear long sleeves, repellent and a net. Warmth and humidity after rain speed up mosquito development. An invasive plant that grows along stream banks and on wet meadows. In sunlight its sap causes skin burns. How to protect yourself: Do not touch it and do not walk through the vegetation. If the sap gets on your skin, wash it off with water and soap and protect the area from the sun. See a doctor for larger burns. Transmits tick-borne encephalitis and Lyme disease. It waits in tall grass and in the vegetation along banks. How to protect yourself: From spring to autumn check yourself after fishing, use repellent and tuck long trousers into your socks. Remove a tick as soon as possible with tweezers. A vaccination against encephalitis exists. A shy predator of the forests. It comes to the water at night and at dusk. How to protect yourself: Attacks on people are very rare. Keep your camp tidy, do not feed wildlife and keep your dog on a leash. A venomous snake that basks on rocky slopes, in wetlands and at forest edges near water. How to protect yourself: It is shy and bites only when threatened. On rocky banks do not reach with your hand between the stones, and wear sturdy footwear. After a bite stay calm, do not move the affected limb and call 112. Large biting flies. They are most active on hot, windless days near water and on meadows. How to protect yourself: They sting painfully, especially in summer around midday. Light-colored clothing with long sleeves and repellent help. Wildlife, plants and hazards: records come from observations and also reflect where observers move around; they are not density measurements or a guarantee of an encounter. They apply to the surroundings of about 35 × 55 km. Bedrock, watercourse and springs on the map, values at the location of the water, geomagnetic activity and earthquakes. This is information about the environment; only small hypotheses marked with a confidence level (faults and rocks, geomagnetic storm) enter the score. The bedrock map needs JavaScript to be turned on. Geological map of Slovakia 1 : 50,000: rocks beneath the surface, from alluvial gravels and sands through clays to granites and limestones. Colors follow the ŠGÚDŠ legend; clicking the map shows a description of the rock at that spot. For anglers: Gravel bars and rocky riffles give a clean bottom and habitat for zander, perch and barbel. Clayey and muddy ground holds food for carp and bream. Limestone and dolomite give harder water that is richer in food than granite and quartzite. Radon risk of the bedrock (low, medium, high). It is based on the radioactivity of rocks and on fissures. The map shows the bedrock, not radon in water. For anglers: Radon is a natural tracer of groundwater. Bedrock with a higher radon risk (granite, gneiss, tectonic faults) tends to be where fissure water comes to the surface. Most of Slovakia is "medium", so mainly a high risk is of interest. Equivalent uranium in surface rocks from airborne gamma spectrometry (ppm). From 4 ppm the bedrock is usually classified as having an elevated radon risk. For anglers: A high uranium level is a sign of granite, gneiss and black shales, that is, rocks from which radon and dissolved substances get into the water. It has no direct meaning for bites, but it helps to read the geology of the area. Gamma radiation dose rate in air (nGy/h) from an airborne survey. It is the natural background of the bedrock, not pollution. For anglers: Higher values are found in rocks rich in uranium, thorium and potassium (granite, gneiss, flysch with shales). It complements the uranium map; for an angler it mainly shows where the bedrock changes. Anomalies of the Earth's magnetic field (ΔT, in nT) caused by rocks with magnetic minerals, such as volcanic rocks, basalts or amphibolites. For anglers: Fish (especially salmonids and eels) sense the magnetic field. Whether local anomalies affect their movement and bites has not been shown; it is treated as a hypothesis. Click or tap the map to find the value at that location. low Bedrock with a low radon share. 2.3ppm common Typical background of the rocks. 7.6ppm below the crustal average Natural background of the rocks. 1.16% below the crustal average Natural background of the rocks. 47nGy/h around the world average Natural background of the bedrock. -86nT below the average of the surroundings Deviation of the magnetic field from the average of the surroundings. The values apply to a single spot (marked with a dot on the map), not as an average of the whole watercourse or river basin. Radon is a natural tracer in groundwater; the map does not include radon in water, only the bedrock risk. Mark on the dial: the average of the upper continental crust (uranium 2.7 ppm, thorium 10.5 ppm, potassium 2.3%; Rudnick and Gao 2003) and the world average of the natural outdoor dose 59 nGy/h (UNSCEAR 2000). The needle does not swing towards “good” or “bad”; it only shows where the value lies. Elevated uranium or radon is only information about the rock. It has no proven significance for bites; it helps to read what bedrock the water comes from. up to 250 m fault nearby Tectonic fault on the geological map. 3 groundwater by the watercourse Within 1 km. covered by younger sediments Fissure groundwater flows out of the bedrock along faults and at springs. It tends to be cooler in summer and warmer in winter than the water in the stream, so according to anglers' experience fish stay near such places in extreme weather (summer and winter islands of a more suitable temperature). However, fresh fissure water can have little oxygen. This is anglers' experience, not a phenomenon measured at this fishing district. Faults are from the geological map at 1 : 50,000. Springs come from a hydrogeological map that covers only some regions, so zero does not mean there are no springs there. The line is the water of the fishing district, the light band is the 3 km zone in which boreholes, mine workings and burdens were searched for. The map shows the nearest objects (at most a few dozen from each register), not all of them. The points correspond to the position in the register; area objects are marked by their centre. River alluvium100% of the water line Gravelly and sandy bottom and floodplains; the water is replenished from groundwater in the alluvium. Geological Map of Slovakia 1:50,000. pH 7.0modelled estimate water type Ca–HCO₃–SO₄ Mineralisation 78.5 mg/l, soft water (2.4 °dH). Interpolation of measurements from the Geochemical Atlas of Slovakia, not a measurement in the stream. 1 from 15elements in the top 10 % highest: Vanadium 104 mg/kg Position of the highest-ranked element among the sample points on streams in Slovakia: percentile 90. Interpolation of the Geochemical Atlas of river sediments. 45°C at 1,000 m depth heat flow 75 mW/m² At a depth of 2,000 m about 85 °C (increase of 40 °C per kilometre). Atlas of Geothermal Energy of Slovakia. 0samples with gold 5 ore minerals in the sediment No gold was found in river sediment samples within 1 km of the water. The samples do not cover every stream, so this does not mean there is no gold here. 1 from 9indicators in the top 5 % highest: Cadmium 1.30 μg/l Position of the highest measured value in the distribution of all surface water samples in Slovakia: percentile 97 (Rybnica, potok). 35boreholes within 3 km 297 water analyses nearby Of these, 35 have an archive report from Geofond. The boreholes are hydrogeological, geological, engineering-geological and other. 29°C at the wellhead 1 geothermal borehole within 10 km Warmest: Sobrance – TMS-1, yield 4.0 l/s, 7.3 km from the water. 8sites within 3 km 8 landfills No environmental burden is registered within 3 km; landfills are only recorded. 7records within 5 km 7 ore occurrences Geofond registers, the metallogenetic map and the mineral resources map. 34areas within 3 km Documented landslides in the Geofond register. A landslide into a stream can cloud the water and change the bed. The data come from registers, maps and atlases of the State Geological Institute of Dionýz Štúr and describe the environment around the water. Proximity of a mine working or burden does not mean the water is polluted. The chemistry of water and sediments is a modelled estimate from interpolated maps of the Geochemical Atlas of Slovakia, not current monitoring or a measurement in the stream. Detailed geology and geochemistry of the whole stream: rock under the water, water composition, elements in sediments, radiation, geothermal potential, metals, gold in sediment, mine workings, boreholes with analyses. Highest forecast Kp in the next 24 hours: 4.7 (unsettled field). Kp (0 to 9) measures the fluctuation of the Earth's magnetic field caused by the solar wind. From 5 it counts as a geomagnetic storm. Fish, especially salmonids and eels, sense the magnetic field. That their bites depend on Kp has not been shown, though: these are anglers' observations and hypotheses. The value is the same for the whole of Slovakia. It enters the activity score only during a strong geomagnetic storm (a hypothesis, −1 to −2 points). According to angling lore, fish (especially catfish and eels) react restlessly to tremors beforehand or stop biting. This is not reliably proven, and with weak tremors it is coincidence. People mostly do not notice deeper tremors from the Carpathians (for example near Komárno and Dobrá Voda) at all. The GEOFON catalog is global; weak tremors near Slovakia may not all be in it. It is not counted in the activity score. Data: © ŠGÚDŠ (geological, geophysical and hydrogeological maps), NOAA SWPC (Kp index), GFZ GEOFON (earthquakes). A link between the geomagnetic field, tremors or radon and fish bites has not been reliably proven, so they are not counted in the activity score. The method is described in Methodology. Sentinel-2 (optical) and Sentinel-1 (radar), updated roughly every 6 days The watercourse is narrower than a satellite pixel (10 m). The values are therefore taken from a strip around the fishing district line and from pixels where water mixes with the bank, so they are only approximate and may also show the bank. The water surface area is not assessed for a watercourse, and estimates over the water appear in the image only where the watercourse is wider than a satellite pixel. The share of the area with green vegetation (plants on and just below the surface, reeds at the bank). A strip of reeds at the banks may also be counted, so values on small areas may appear higher. Sentinel-2, 5 Nov 2026, 100% of the area cloud-free The share of the area where the satellite sees ice or snow. Over the last 20 days the highest was 0%. The satellite cannot determine the thickness or load-bearing capacity of the ice. Never go onto the ice based on this figure. Sentinel-2, 5 Nov 2026, 100% of the area cloud-free Data have been stored since 27 Aug 2026 (12 periods of 5 days); the charts show how they develop. Download history (CSV) Estimates from satellite images with a resolution of 10 to 20 m, not a measurement in the water. They are affected by clouds, shadows, wind and banks. Do not use them to decide about swimming or going onto the ice. Data: Contains modified Copernicus Sentinel data 2026, ESA, Copernicus Data Space Ecosystem. The procedure is described in the Methodology. Changes in the surroundings and nature from 2019 to 2025: how the banks, vegetation and landscape around the water change. The images switch automatically; you can also browse them by hand. Orthophoto mosaic of Slovakia © GKÚ Bratislava, NLC Zvolen. The year and day of imaging depend on the location, so individual years may differ in season and weather.
By the water now
Fishing conditionsFish activity indexOur calculation (0–100): the base is set by water temperature, adjusted by light, turbidity, oxygen, weather and other factors according to how well they are supported by studies. For each factor you can see the confidence and the source. A planning aid, not a bite forecast.
Fishing conditions
Fish activity indexOur calculation (0–100): the base is set by water temperature, adjusted by light, turbidity, oxygen, weather and other factors according to how well they are supported by studies. For each factor you can see the confidence and the source. A planning aid, not a bite forecast.Water
Water level
Water levelThe water level at the nearest SHMÚ gauge in centimetres above the gauge zero. It is the water level at the station, not the depth of the water at the fishing district.Modelled flow
Modeled flowAn estimate of the amount of water in the river (m³/s) from the GloFAS model, not a measurement. The resolution is about 5 km, so on small streams it may show a larger river nearby.Elevation profile of the watercourse
Elevation profileHow the altitude of the watercourse changes downstream. It is calculated from a digital relief model (tens of metres), not from a water-level measurement, so it is approximate, especially for narrow streams.Weather and forecast
Weather and forecast
Sky: sun, moon and solunar windowsSolunar periodsCalculated from the position of the Moon: major periods (about 2 h) around the Moon's passage above and below the horizon, minor periods (about 1 h) around moonrise and moonset. A scientifically unconfirmed theory: in a study of 361 fishing trips (Quigley et al. 2023) it did not predict bites. We treat it as a hypothesis with a weight of at most ±2 points.
Sky: sun and moon
Solunar periodsCalculated from the position of the Moon: major periods (about 2 h) around the Moon's passage above and below the horizon, minor periods (about 1 h) around moonrise and moonset. A scientifically unconfirmed theory: in a study of 361 fishing trips (Quigley et al. 2023) it did not predict bites. We treat it as a hypothesis with a weight of at most ±2 points.Sun
MoonMoon phaseAt full and new moon the gravitational effect is strongest. On a clear full-moon night predators and carp often feed at night, and the day after may be weaker.
Windows of the daySolunar periodsCalculated from the position of the Moon: major periods (about 2 h) around the Moon's passage above and below the horizon, minor periods (about 1 h) around moonrise and moonset. A scientifically unconfirmed theory: in a study of 361 fishing trips (Quigley et al. 2023) it did not predict bites. We treat it as a hypothesis with a weight of at most ±2 points.
Map and fishing district data
48.85481, 22.1891
OpenStreetMap
Fishing district details
Law and fishing rules
Closed season for all fish
Section 13, paragraph 1 of the ActDaily fishing hours
§ 11 of the DecreeRods, baits and fishing days
§ 16 of the ActHow many fish you may keep per day
§ 14 of the DecreeProtection periods by species§ 10 of the Decree
Minimum sizes§ 12 of the Decree
Show as a list
Before and after fishing
News from the organization and catches from the fishing district
Catches from the fishing district
Other fishing districts nearby
On the Okna stream
4-1560-1-1CarpOkna č. 1a
Sobrance, Košice Region
4-1561-4-1Salmonid (trout)Okna č. 1b
Sobrance, Košice RegionNearest in the basin
4-3970-1-1CarpVN Vyšná Rybnica
Sobrance, Košice Region
4-0910-4-1Salmonid (trout)Jovsanský potok
Humenné, Prešov Region
4-0040-4-1Salmonid (trout)Barnov potok č. 2
Humenné, Prešov Region
4-2390-1-1CarpSobranecký potok č. 2
Sobrance, Košice Region
4-0950-4-1Salmonid (trout)Kamenica č. 2
Humenné, Prešov Region
4-3870-1-1CarpVN Veľká Bystrá
Prešov RegionTerrain in 3D
Water according to public sources
Water suitability for the fishing district type
Water suitability for the district typeIndex 0 to 100: how well the properties of the water match the needs of trout, grayling or carp, depending on the district type. It is not a bite forecast or a statement about which fish live there.What we know about it
What we know about it
What we know about it
What we know about it
What we know about it
What we know about it
What we know about it
How this water would suit each type
What follows from this
Public sources in the conditions scoreData on oxygen, nutrients, reservoir depth, watercourse size, bottom, fish species and insect swarming slightly adjust the "Fishing conditions" score. Each adjustment is shown separately in the score breakdown.Water and oxygen+1
What we know about it
What we know about it
What we know about it
What we know about it
Watercourse, reservoir and bottom−1
What we know about it
Do not change the score
Water quality
Dissolved oxygen (EEA)How much oxygen is dissolved in the water according to the nearest monitoring station (average of recent years). Trout and grayling need over 8 mg/l; cyprinids can cope with less.Water pollution
Water pollution (SHMÚ)Water quality indicators that fail the standards at the nearest monitoring site on the same watercourse in the SHMÚ yearbooks for 2022 to 2025.Surface water: nearest monitoring site
Groundwater nearby
Groundwater nearby (SHMÚ)Measured groundwater values from stations within 10 km of the fishing district (nitrates, harmful substances, ammonium, iron, chlorides) and the SHMÚ yearbooks.Groundwater within 10 km (8 stations)
Measured values, year 2025, sampling 28 Apr 2025
Measured values, year 2025, sampling 3 Jun 2025
Measured values, year 2025, sampling 11 Nov 2025 (2 samplings, the highest value of the year for each substance)
Show 5 more
Measured values, year 2025, sampling 9 Jun 2025
Measured values, year 2025, sampling 3 Jun 2025
Measured values, year 2025, sampling 2 Jun 2025
Measured values, year 2025, sampling 11 Nov 2025 (2 samplings, the highest value of the year for each substance)
Measured values, year 2025, sampling 23 Sep 2025
River basin and reservoir
Reservoir depth (HydroLAKES)Average depth, volume and water retention time in the reservoir from the HydroLAKES database (WWF). The depth is estimated by a model from the surrounding terrain, so it is approximate.Bottom and bedrock
Bottom and bedrock (ŠGÚDŠ)The bedrock under the water according to the hydrogeological map of Slovakia at 1 : 50,000 (ŠGÚDŠ). It tells whether the surroundings are gravelly, sandy, clayey, muddy or rocky.Groundwater: measured values
Groundwater nearby (SHMÚ)Measured groundwater values from stations within 10 km of the fishing district (nitrates, harmful substances, ammonium, iron, chlorides) and the SHMÚ yearbooks.Ammonium
Nitrites
Nitrates
Oxygen
Water temperature
pH
Water hardness
Iron
Manganese
Chlorides
Sulphates
Conductivity
Metals and metalloids
Pesticides
Solvents and benzene
PAHs (combustion, petroleum substances)
How it affects fish and the water
Fish, wildlife, plants and hazards around the waterWildlife and hazards by the water (GBIF)Game animals, birds, plants and hazards (bear, ticks, mosquitoes, giant hogweed) that people have recorded around the water. It is not part of the fishing conditions score and is for information only.
BirdMallard
Most records: May.
About the species
BirdGrey heron
Most records: May.
About the species
BirdGreat egret
Most records: May.
About the species
BirdMute swan
Most records: May.
About the species
BirdBlack-headed gull
Most records: May.
About the species
WildlifeMayflies
Most records: June.
About the species
WildlifeDragonflies
Most records: July.
About the species
WildlifeFire salamander
Most records: April.
About the species
WildlifeGrass snake
Most records: June.
About the species
WildlifeCommon toad
Most records: April.
About the species
WildlifeEurasian beaver
Most records: June.
About the species
WildlifeDaubenton's bat
Most records: April.
About the species
Invasive plantJapanese knotweed
Most records: July.
About the species
Invasive plantHimalayan balsam
Most records: September.
About the species
PlantBlack alder
Most records: September.
About the species
PlantYellow flag iris
Most records: May.
About the species
PlantCommon reed
Most records: September.
About the species
PlantYellow water lily
Most records: July.
About the species
RiskMosquitoes
Most records: June.
How to protect yourself
RiskGiant hogweed
Most records: July.
How to protect yourself
RiskCastor bean tick
Most records: May.
How to protect yourself
RiskGray wolf
Most records: May.
How to protect yourself
RiskCommon viper
Most records: July.
How to protect yourself
RiskHorseflies
Most records: July.
How to protect yourself
Photo credits
Ground under the water: geology, faults and radon
low 36.7%
medium 63.0%
high 0.3%
no data
0 – 1
1 – 2
2 – 3
3 – 4
4 – 5
5 – 7
7 – 35no data0 – 2020 – 40
40 – 6060 – 8080 – 100100 – 140
140 – 180
180 – 220
220 – 999
-1 217 – -1 000
-1 000 – -250
-250 – -200
-200 – -190
-190 – -180
-180 – -170
-170 – -160
-160 – -150
-150 – -140
-140 – -130
-130 – -120
-120 – -110
-110 – -100
-100 – -90
-90 – -80
-80 – -60
-60 – -40
-40 – -20
-20 – 0
0 – 10
10 – 20
20 – 30
30 – 40
40 – 50
50 – 70
70 – 100
100 – 150
150 – 200
200 – 250
250 – 300
300 – 400
400 – 500
500 – 600
600 – 700
700 – 800
800 – 900
900 – 1 000
1000 – 1 100
1100 – 1 130Values at the water spot
Values at the water spotBedrock radon risk, uranium, thorium, potassium, gamma radiation and magnetic anomaly at a single spot by the water (marked with a dot on the map).Radon risk of the bedrock
Uranium (eU)
Thorium (eTh)
Potassium (K)
Gamma radiation
Magnetic anomaly (ΔT)
Faults and springs
Faults and springsThe distance to the nearest tectonic fault on the geological map and the number of springs nearby. Fissure groundwater flows out along faults.Nearest fault
Springs and outflows
Geology nearby: rock, water, sediments, boreholes
Geology and geochemistry around the waterRock under the water, composition of water and sediments according to the atlases, radioactivity, geothermal potential, boreholes, old mine workings, deposits, burdens, landslides and gold in sediments, from ŠGÚDŠ maps and registers.Rock under the water
Water according to the atlas
Elements in river sediment
Heat underfoot
Gold in river sediment
Trace elements in the stream water
Boreholes and groundwater analyses
Geothermal energy
Environmental burdens and landfills
Deposits and ore occurrences
Landslides and slope deformations
Geomagnetic activity
Geomagnetic activity (Kp)The planetary Kp index (0 to 9) measures the fluctuation of the Earth's magnetic field. From 5 it counts as a geomagnetic storm. The last 48 hours and a forecast for 24 hours are shown.Earthquakes nearby
Earthquakes nearbyTremors recorded within 150 km of the water in the last 30 days (GFZ GEOFON catalog).From space: what the Copernicus satellites show
Surface overgrowth
Surface overgrowthThe share of the fishing district's area where the satellite sees green vegetation (NDVI index above 0.3): floating and emergent plants and reeds at the bank.Ice on the surface
Ice on the surfaceThe share of the area where the satellite sees ice or snow. It cannot determine the thickness or load-bearing capacity of the ice.Historical images
Nov0% illuminated
Nobody has recorded a catch in this fishing district yetBe the first: after approval it will also appear here in the ranking.
Water of average suitability for trout
Stream zoneLevel of evidence: Partly supported
Water hardnessLevel of evidence: Hypothesis
Water acidity (pH)Level of evidence: Partly supported
Oxygen in the waterLevel of evidence: Proven
MineralizationLevel of evidence: Hypothesis
Nutrients and foodLevel of evidence: Partly supported
Metals in sedimentLevel of evidence: Partly supported
Public data about this water hardly change the activity score.
Dissolved oxygenLevel of evidence: Proven
+2
Nutrients in the waterLevel of evidence: Partly supported
+1
Water hardnessLevel of evidence: Hypothesis
−1
Ammonium ions in waterLevel of evidence: Partly supported
−1
Bottom by geologyLevel of evidence: Hypothesis
−1
Dissolved oxygen10.9 mg/l
Well oxygenatedlowest measured 9.8 mg/l, 8 measurements, up to 2008
Water acidity (pH)7.7
Balanced8 measurements, up to 2008
NitratesNutrients in the water (EEA)Nitrates (mg of nitrogen per litre) and phosphates (mg of phosphorus per litre) from a neighbouring monitoring station. Many nutrients mean rich food, but also algae and oxygen swings.1.0 mg N/l
Medium8 measurements, up to 2008
Phosphorus (phosphates)Nutrients in the water (EEA)Nitrates (mg of nitrogen per litre) and phosphates (mg of phosphorus per litre) from a neighbouring monitoring station. Many nutrients mean rich food, but also algae and oxygen swings.0.02 mg P/l
Low8 measurements, up to 2008
Ammonium0.33 mg N/l
Elevated8 measurements, up to 2008
Conductivity177 µS/cm
Normal mineralisation8 measurements, up to 2008
Senné, aboveOkna, river km 0.7 · 8.6 km from the fishing district
no unmet standard2022202320242025
Poruba pod VihorlatomMichalovce district · borehole or well · 3.0 km from the fishing district
no exceedance in 20252017 to 2025
JasenovSobrance district · borehole or well · 4.8 km from the fishing district
no exceedance in 20252017 to 2025
UbrezSobrance district · borehole or well · 6.4 km from the fishing district
natural substances only2017 to 2025
Ruska Bystra – pod DielomSobrance district · spring · 6.5 km from the fishing district
no exceedance in 20252017 to 2025
JovsaMichalovce district · borehole or well · 7.2 km from the fishing district
natural substances only2017 to 2025
ChonkovceSobrance district · borehole or well · 7.5 km from the fishing district
natural substances only2017 to 2025
Horna-sobranceSobrance district · borehole or well · 8.8 km from the fishing district
natural substances only2017 to 2025
Kusin Vn-34Michalovce district · borehole or well · 8.8 km from the fishing district
no exceedance in 20252017 to 2025
Clays and loams
Geology
Radon risk
Uranium (eU)
Gamma radiation
Magnetics
dry groundwaterNDWI index
bare grounddense vegetationNDVI index
clearturbid0 to 90 FNU
littlea lot of chlorophyllNDCI index
sparsedense vegetationNDVI index
0 % of areaClean surface
0 % of areaNo ice