Fishnets

products marked by this sign are also suitable for scientific research Petr Pokorný Pavlína Blažková Renata Kmochová Gabriela Jungbauerová Karla Pokorná Dagmar Strnadová

Petr Pokorný and his colleagues are looking forward to cooperation with you.

Jana Švarcová Miloslav Kinkor Zdeněk Novák Stanislava Kočvarová

Dear business friends, let me introduce in short CURRENTLY WE PRODUCE NETS FOCUSING ON: the company POKORNÝ–SÍTĚ s. r. o. (POKORNY–NETS) fish, fish farming and fishing, ichthyological research The company has been found since September 1990 by Mr. Petr Pokorný sport, protective nets for sportgrounds in time of birth of free trade in Czech Republic. Primary focus of activity aviary, breeding and protection against birds was production of fishing nets for freshwater husbandry and sport nets safety, fall of persons and objects trading. During 1992 the company moved to the first rented spaces and net adrenaline parks engaged first regular employee. The company started production of decorative, artistic composition sport and protective nets for sportground. Nets were produced by hand cords and ropes made netting by number of home workers. Since 1996 the company became dynamically developing and built up new manufacture place Our production is very flexible to customer requirements. in Brloh. Evolution of company continues in Brloh and technological Our advantage is higly precise manufacturing process of nets process, raw materials and production range are standardized. within short delivery times. Working team is established here and our wish is correctly and precise Our years of experience enable us to recommend the most manufactured product and customer satisfation. suitable net to customers for their specific needs. Assessment of fish communities of lakes and reservoirs

Jan Kubečka Jiří Peterka Marie Prchalová Martin Čech Mojmír Vašek Milan Říha

Josef Matěna Tomáš Jůza Jaroslava Frouzová Petr Blabolil Michal Tušer Vladislav Draštík

The Fish Ecology Unit (FishEcU) A holistic approach to freshwater research as conduct- Many sampling approaches were studied to identi- ed by the Institute of Hydrobiology requires quantification fy their selectivity and ensure that the optimal sam- research group was founded as a of all important species and size/ age groups in all impor- pling approach is chosen. (True picture of the fish stock, part of the Institute of Hydrobiology, tant habitats of reservoirs and lakes. Verification of result Kubečka a kol. 2009) reliability often required the simultaneous use of several Biology Center of the Academy of research methods. Methodical treatises and handbooks: Science of the Czech Republic, v.v.i. We developed approaches including, but not limited to, Methodology of sampling and processing of fish sam- beach seine nets, scientific echosounders, gillnets, trawls, ples of lentic waters. Methodology VÚV, TGM, Praha, 22 The Fish Ecology Unit comprises of 30 members including purse seine nets, electrofishing, fish traps, and visual pages (Kubečka J. & Prchalová M., 2006; in Czech). senior scientists, junior researchers, students and techni- observations. Czech methodology of fish community monitoring in cians, who conduct surveys of reservoirs and lakes in the FishEcU members often collaborate with the Pokorný-Sítě reservoirs and lakes? (Kubečka et al. 2010; in czech). Czech Republic and other countries. FishEcU was estab- company to develop novel modications to their nets and Methodology for the assessment of the ecological po- lished to further the understanding of the ecological func- sampling gear, and their instructions for use. Many sampling tential of heavily modified and artificial water bodies– tion of fish communities in reservoirs and lakes. Meth- techniques developed this way have found their place into lake category (Borovec et al. 2013; in Czech) odology development was essential for the quantitative standard sampling methods for reservoir and lake fish com- Development and quantification of sampling methods assessment of fish densities in various types of habitats. munities. is also found in the European Standard methodology of

1 fish sampling. FishEcU members take part in meetings Stomach content and age analyses Tušer M., Frouzová J., Ricard D., Mrkvička T., Sajdlová held yearly, where European Standards are continually Population dynamics and behavior of fish species Z., Vejřík L., Šmejkal M., Borovec J., Matěna J., Boukal developed. Monitoring of presence and rescue relocation of the D., Kubečka J. 2013. What do fish indicate about the large bivalves quality of water ecosystems. In: Kosour D., (ed). Vodní In addition to the role of fish communities in lentic nádrže 2013, 25-26.9. 2013, Brno, Povodí Moravy s.p.: ecosystems, the following topics are also studied: Highlights of our research: 51-56. (in Czech). Difficulties in monitoring and assessing the ecological Development of horizontal acoustic methods for fish Čech, M., Kubečka, J., 2002: Sinusoidal cycling swim- potential of fish communities. (The EU Water Frame- surveys (Kubečka, 1996, Kubečka & Wittingerová, 1998) ming pattern of reservoir fishes. Journal of Fish Biol. 61: work Directive 2000/60/ES) Sinusoidal cycling swimming pattern of reservoir fishes 456-471. The influence and practical implementation of various (Čech & Kubečka, 2002) Čech M., et al. 2005: Diel vertical migrations of bathype- fish management strategies and establishing purpose- Patterns of occurrence of bathypelagic perch fry (Čech lagic perch fry. J. Fish Biology 66: 685-702. ful fish stocks, conservation and support of ecologically et al. 2005) Hladík, M., Kubečka, J., (2003) Fish migration between valuable fish communities. Patterns of fish distribution in reservoirs (Prchalová et al. the reservoir and its main tributary. Hydrobiologia 504: 2008, Muška et al. 2013, Říha et al. 2014), saturation of 251-266. Methodological development lead to the establish- gillnets (Prchalová et al. 2011) and their selectivity (Prch- Juza, T., Kubecka, J., 2007. Efficiency of three fry trawls ment of a international research infrastructure, where alová et al. 2008, 2009) to sample freshwater pelagic fry community. Fisheries we gather unique sampling gears and know-how, The importance of tributaries for fish communities in Research, 85, 3: 285–290. which can be used in the Czech Republic and sur- reservoirs (Hladík & Kubečka 2003, Říha et al. 2013) Jůza, T. Mrkvička, T., Blabolil1, P., Čech, M., Peterka, rounding countries. Development of fry trawling (Jůza & Kubečka 2007) J.,Vašek, M., Kubečka, J. 2013. Occurrence of age-0 The considerable advancement in knowledge about dwarf pikeperch in late summer – an overlooked phe- FishEcU members conduct research of fish communities in fish fry distribution in reservoirs (Vašek et al. 2006, Kra- nomenon in reservoirs. Journal of Fish Biology, 83, many countries. International conferences are held regularly tochvíl et al. 2013, 2014, Jůza et al. 2014) 1444–1452. by FishEcU and students from several universities are su- Selectivity and usefulness of trawls and purse seine Jůza T., Rakowitz, G., Draštík, V., Blabolil, P., Herzig, pervised by members. An overview of sampled water bodies nets for fish sampling (Rakowitz et al. 2012, Říha et al. A., Kratochvíl, M., Muška, M., Říha, M., Sajdlová, Z., and additional information is found at www.fishecu.cz. This 2012) Kubečka J., 2013. Avoidance reactions of fish in the web page also contains our most recent published research. Analysis of beach seine net efficiency for sampling of trawl mouth opening in a shallow and turbid lake at fish communities (Říha et al. 2008, 2011) night. Fisheries Research 147: 154-160. FishEcU research activities include: The evaluation of the long-term development of the fish Jůza, T., Vašek, M., Kratochvíl, M., Blabolil, P., Čech, M., Conducting complex quantitative and qualitative esti- community in the Římov Reservoir (Říha et al. 2009) Draštík, V., Frouzová, J., Muška, M., Peterka, J., Prch- mates of the fish stock. Research also involves tests of The discovery of plankton stages of tubenose goby alová, M., Říha, M., Tušer M., Kubečka, J., 2014. Chaos accuracy of methods used, and development of new (Vašek et al. 2011) and “dwarf” pikeperch in open water and stability of age-0 fish assemblages in a temperate methods. of reservoirs (Jůza et al. 2013) deep reservoir: unpredictable success and stable habi- The clarification of fish function in food webs in water Development of a national methodology for the assess- tat use. Hydrobiologia, 724, 1: 217-234 bodies ment of the ecological potential in water bodies in the Kratochvíl, M., Mrkvička, T., Vašek, M., Peterka, J., Providing important background knowledge for fish lake category based on the fish community (Blabolil et Čech, M., Draštík, V., Jůza, T., Matěna, J., Muška, M., stock management al. 2013, Borovec et al. 2013) and evaluation of popula- Seďa, J., Znachor, P. & Kubečka, J. (2012). Littoral age Discovering principles in distribution, behavior, feeding tions and the role of piscivorous fish in reservoirs (Vašek 0+ fish distribution in relation to multi-scale spatial het- activity, abundance and biomass of fish in water bodies et al. 2013) erogeneity of a deep-valley reservoir. Hydrobiologia (2012) 696:185–198. In addition to primary and applied research, FishEcU Relevant published articles: Kratochvíl, M., Vašek, M., Peterka, J., Draštík, V., Čech, also promote the development in several fields: Borovec, J., Hejzlar, J., Znachor, P., Nedoma, J., Čt- M., Jůza, T., Muška, M., Matěna, J. Kubečka, J. 2014 Complex (holistic) surveys of fish communities vrtlíková, M., Blabolil, P., Říha, M., Kubečka, J., Ricard, Towards a better understanding of small scale distribu- Hydroacoustic assessment of fish stock abundance D., Matěna, J. Methodology for the assessment of tion of littoral age 0-fish in a deep-valley reservoir: day Sampling with fish traps, beach seine nets, gillnets, the ecological potential of heavily modified and artificial or night surveys?. Hydrobiologia 728:125–139 purse seine nets and trawls water bodies– lake category. Ministry of the environ- Kubecka, J. 1996: Use of horizontal dual-beam sonar for Harmless methods to fish: visual observation and elec- ment of the Czech Republic, 35 p. (in Czech). fish surveys in shallow waters. Cowx I.G. {ed.}: Stock as- trofishing boat Blabolil P., Říha M, Peterka J., Prchalová M., Vašek M., sessment in inland fisheries. Blackwell, Oxford, 165-178. Sampling of fish fry communities Jůza T., Čech M., Draštík V., Kratochvíl M., Muška M., Kubecka, J., Wittingerova, M. 1998. Horizontal beaming

2 as a crucial component of acoustic stock assessment velopment of fish populations in the Římov Reservoir. fish covering the littoral and pelagial zones in a model in freshwater reservoirs. Fisheries Research. 35, 99-106. Fisheries Management and Ecology, 16: 121-129. reservoir. Hydrobiologia. Kubečka, J., et al., 2009 The true picture of a lake Říha M., Kubečka J., Prchalová M., Mrkvička T., Čech Vašek M., Kubečka, J., Matěna, J. and Seďa J. 2006 or reservoir fish stock: a review of needs and pro- M., Draštík V., Frouzová J., Hohausová E., Jůza T., Kra- Distribution, size and diet of 0+ fish within a can- gress. Fisheries Research, 96, 1: 1-5. DOI: 10.1016/j. tochvíl M., Peterka J., Tušer M. & Vašek M. (2011) The yon-shaped reservoir in late summer. Intern. Rev. Hyd- fishres.2008.09.021 influence of diel period on fish assemblage in the un- robiol. 91: 178-194. Kubečka, J., Frouzová, J., Jůza, T., Kratochvíl, M., Říha, structured littoral of reservoirs. Fisheries Management Vašek, M., et al., 2004. Longitudinal and vertical spatial M., Prchalová, M., 2010. Methods of monitoring of the and Ecology 18, 339–347. gradients in the distribution of fish within a canyon-shaped fish communities of reservoirs and lakes. Metodika Říha M., Jůza T., Prchalová M., Mrkvička T., Čech M., reservoir. Intern. Rev. Hydrobiol. 89, 352-362. monitorování rybích společenstev nádrží a jezer. Meto- Draštík V., Muška M., Kratochvíl M., Peterka J., Tušer Vašek M., Jůza T., Čech M., Kratochvíl M., Prchalová M., dická příručka, Vydavatel/Publisher: Biologické cen- M., Vašek M., Kubečka J. 2012. The size selectivity of Frouzová, J., Říha M., Tušer M., Seďa J., Kubečka J. 2011. trum AV ČR, 1-64. ISBN 978-80-86668-08-6 the main body of a sampling pelagic pair trawl in fresh- Pelagic occurrence of freshwater tubenose goby Proter- Muška, M., Tušer, M., Frouzová, J., Draštík, V., Čech, M., water reservoirs during the night. Fisheries Research orhinus semilunaris (Heckel, 1837) in a Central European Jůza, T., Kratochvíl, M., Mrkvička, T., Peterka, J., Prch- 127– 128. 56– 60. reservoir. Journal of Fish Biology 78, 953–961. alová, M., Říha, M., Vašek, M., Kubečka, J. 2013. To mi- Říha, M., Hladík, M., Mrkvička, T., Prchalová, M., Čech, Vašek M., Prchalová M., Peterka J., Ketelaars H.A.M., grate, or not to migrate: partial diel horizontal migration M., Draštík, V., Frouzová, J., Jůza, T., Kratochvíl, M., Pe- Wagenvoort A.J., Čech M., Draštík V., Říha M., Jůza of fish in a temperate freshwater reservoir. Hydrobio- terka, J., Vašek M., Kubečka J., 2013. Post-spawning T., Kratochvíl M., Mrkvička T., Blabolil P., Boukal D.S., logia 707: 17-28. dispersal of tributary spawning fish species to a reser- Duras J., Kubečka J., 2013: The utility of predatory fish Prchalová, M., Kubečka J., M. Říha, R. Litvín, M. Čech, voir system. Folia Zoologica 62 (1): 1–13. in biomanipulation of deep reservoirs. Ecological Engi- J. Frouzová, M. Hladík, E. Hohausová, J. Peterka, M. Říha, M., et al.,., 2014. Changes in diel habitat use of neering 52: 104-111. Vašek. 2008 Overestimation of percid fishes (Percidae) in gillnet sampling. Fisheries Research 91: 79-87. Prchalová, M., et al., 2008 Gradients of fish distribution in a canyon-shaped reservoir. Journal of Fish Biology 73: 54-78. Prchalová, M., Kubečka, J., Ř íha, M., Mrkvička, T., Vašek, M., Jůza, T., Kratochvíl, M., Peterka, J., Draštík, V., Křížek, J., 2009. Size selectivity of standardized mul- timesh gillnets in sampling coarse European species. Fisheries Research, 96, 1: 51-57. Prchalová M., et al.,. (2011). A model of gillnet catch in relation to the catchable biomass, saturation, soak time and sampling period. Fisheries Research 107: 201-209. doi:10.1016/j.fishres.2010.10.021 Rakowitz G., Tušer M, Řiha M., Jůza, T., Balk, H., Kubeč- ka, J. 2012. Use of high-frequency imaging sonar (DID- SON) to observe fish behaviour towards a surface trawl. Fisheries Research 123– 124: 37– 48. Říha, M., Kubečka, J., Mrkvička, T., Prchalová, M., Čech, M., Draštík, V., Frouzová, J., Hladík, M., Hohausová, E., Jarolím, O., Jůza, T., Kratochvíll, M., Peterka, J.,. Tušer M., & Vašek, M. 2008. Dependence of beach seine net efficiency on net length and diel period. Aquatic Living Resources 21: 411-418. Říha, M., Kubečka J., Vašek M., Seďa J., Mrkvička, T., Prchalová M., Matěna J., Hladík M., Čech M., Draštík V., Frouzová J., Hohausová E., Jarolím O., Jůza T., Kra- tochvíl M., Peterka J., Tušer M., 2009. Long-term de-

3 Handling equipment

4 The handling equipment is supplied as: Handling a set consisting of three parts – frame, net and handle each part separately equipment DRILLED FRAME wire diameter 10 or 12 mm opening diameter 10 or 12 mm Frame CONE-SHAPED SOCKET handling equipment is the basic spacing between holes 2.5 or 4 cm made from steel wire conical 2/3 or 4/5 of the perimeter is equipment required by a fisher- length 20 cm, diameter welded tube-shaped or conical socket is 2 cm, 3.2 cm men for handling fish welded to the frame used with conical handle frame is drilled on the perimeter the equipment is essential for frame is doubled – 2 wires are used small and large-scale commercial fishermen Handle either cylindrical or conical shape made from hard wood – ash or beech Usage: direct handling of all kinds of fish removing fish from nets, vats, channels, fish storage ponds, etc. transporting fish CYLINDRICAL HANDLE cylindrical in all length DOUBLED FRAME made in lengths 0.9, 1.1, 1.6 and 1.8 m Equipment with long handles and outer wire diameter 8 or 10 mm the ending is without shaping inner wire diameter 4 or 6 mm deep nets are used for: TUBE-SHAPED SOCKET spacing between wire joints 4 or 6 cm removing fish from the net tubular the whole perimeter is doubled catching fish in restricted spaces – length 20 cm, diameter 2.8 cm fish storage ponds, cage nets, tanks, used with non-shaped handle live boxes

CONICAL HANDLE shaped in all length Net made in lengths 0.9, 1.1, 1.6 and 1.8 m manually sewn, made from strained parts of the handle knitted PA - polyamide cord are made thicker manually attached from non- the end is cone-shaped knitted PA – polyamide net sewn from non-knitted PA – polyamide net MACHINE-MADE HAND-MADE

5 drilled frame – circular frame, drilled frame – circular frame, DRILLED FRAME – CIRCULAR SHAPE hand-made net machine-made net net is attached to drilled holes the binding cord does not wear out

Sizes: - perimeter 140 cm - wire diameter 12 mm - diameter of drilled holes 3.5 mm - the spacing of drilled holes 4 cm - 4/5 of perimeter drilled - cone-shaped socket 20 cm long, diameter 3.2 cm

Design: coating - cone-shaped socket - powder coating, metallized POWDER COATING coating (electroplating) - tube-shaped socket - metallized coating (electroplating) Hand net hand net is suitable for handling fish weighing 0.25 kg or more the depth of the net determines the maximum amount of fish that can fit (5 - 25 kg) the attached net usually has a mesh size larger than 15 mm

Usage: coating - direct handling all kinds of fish caught - removing fish from vats and fishing nets METALLIZED - carrying fish - catching fish in restricted spaces Doubled frame – circular shape net is attached to inner frame outer frame serves as net protection the binding cord does not wear out

Sizes: - outer perimeter – 140 cm - inner perimeter – 120 cm - outer / inner wire diameter 10 / 4 mm - tube-shaped socket 20 cm long, diameter 2.8 cm

Design: - tube-shaped socket coating - metallized coating METALLIZED (electroplating)

6 dip net – doubled frame – irregular half circle, dip net – drilled frame – triangular, Drilled frame – triangular shape mounted & sewn from machine-made net sewn from machine-made net net is attached to drilled holes the binding cord does not wear out

Sizes: drilled frame – triangular – - perimeter 140 cm cone-shaped socket, - wire diameter 10 mm powder coating - drilled holes diameter 2.5 mm - hole spacing 3 cm - ¾ of perimeter drilled - cone-shaped socket 20 cm long, diameter 3.2 cm

Design: coating - cone-shaped socket - powder coating, metallized POWDER COATING coating (electroplating) - tube-shaped socket - metallized coating (electroplating) Dip net

sewn dip net is suitable for handling small fish up to 0.25 kg drilled frame – triangular – drilled frame – triangular – mounted dip net is suitable for handling fish larger 1 kg cone-shaped, metallized tube-shaped, metallized mounted dip net attached to a long handle can remove fish from the net, or catch fish in restricted spaces – fish storage ponds, cage nets, tanks, live boxes coating the type of the net used determines the amount and size of handled fish METALLIZED mesh smaller than 15 mm is usually used for dip nets it is also possible to attach a larger mesh usually used for a hand net

Usage: Doubled frame – irregular half circle removing fish from transport vats net is attached to inner frame removing fish from fishing nets, outer frame serves as net protection channels, storage ponds the binding cord does not wear out fish redeployment catching fish in restricted spaces Sizes: direct handling of all kinds of fish - outer perimeter – 140 cm doubled frame – irregular half circle - inner perimeter – 120 cm – tube-shaped socket, metallized - outer / inner wire diameter 8 / 4 cm - tube-shaped socket 20 cm long, diameter 2,8 cm

Design: - tube-shaped socket coating - metallized coating (electroplating) METALLIZED

7 DRILLED FRAME – TRIANGULAR SHAPE net is attached to drilled holes 1/2 of perimeter drilled

Sizes: - frame perimeter 120 cm, wire diameter 8 mm - 30 cm deep net - tube-shaped socket 10 cm long, diameter 2.8 cm - metallized coating (electroplating)

Triangular fry dip net

sewn dip net is suitable for handling small fish up to 0.25 kg coating mounted dip net is suitable for handling fish larger than 1 kg METALLIZED the type of the net used determines the amount and size of handled fish 4, 6 and 10 mm mesh are usually used for fry dip nets

Usage: Doubled frame – irregular half-circle frame - removing fish from transport vats net is attached to inner frame - removing fish from fishing nets, channels, storage ponds outer frame serves as net protection - fish redeployment the binding cord does not wear out - catching fish in restricted spaces - direct handling of all kinds of fish Sizes: - outer frame perimeter – 120 cm - inner frame perimeter – 100 cm - outer / inner wire diameter 6 / 4 mm - tube-shaped socket 20 cm long, diameter 2,8 cm - metallized coating (electroplating)

coating METALLIZED

8 landing net – doubled frame – irregular half circle, landing net – drilled frame – irregular half circle, Drilled frame – irregular half circle mounted & sewn from the machine-made net hand-made net net is attached to drilled holes on bottom part of the frame the binding cord does not wear out

Sizes: - width 60 cm, height 50 cm - wire diameter 12 mm, metal sheet 5 x 30 mm - frame drilled on bottom part - diameter of drilled holes in metal sheet 3.5 mm - drilled holes spacing – 40 mm - cone-shaped socket 25 cm long, diameter 3.8 cm - metallized coating (electroplating)

coating METALLIZED Special landing net

landing net for individual use for catching smaller amounts of fishes Doubled frame – irregular half circle (50 – 100 kg) in restricted spaces net is attached to inner frame outer frame serves as net protection Usage: the binding cord does not wear out catching smaller amount of fish for retail catching fish in restricted spaces – small tanks, storage ponds, keep nets, channels Sizes: - width 60 cm, height 50 cm - inner perimeter – 120 cm - outer / inner wire diameter 12 / 4 mm - tube-shaped socket 20 cm long, diameter 2.8 cm - metallized coating (electroplating)

coating METALLIZED

9 Weigh net metallic circle with movable hanger The net depth measurement coating serves as a supplementary tool for large scales of handling nets METALLIZED for weighing small amounts of fish up to 20 kg Dip nets and fry dip nets (sewn from machine-made net) the value depth in the table depth measurement states the depth of the net after – machine-made net attaching to the frame measurement procedure – rule is placed across the frame and second rule forms right angle to the center of the net vertical rule indicates the net depth in cm Sizes: the table values are approximate The nets used for hand nets - perimeter 140 cm and may differ slightly in same with any arbitrary mesh size - wire diameter 12 mm type of nets can be used for weigh nets. - metallized coating (electroplating) the sizes are in cm

Net for mechanically-operated dip net Hand net – dip net – fry dip net – landing net mechanically-operated dip net is used for removing fish from nets (hand-made and machine-made net) during the fishing out of the pond 100 – 150kg of fish fit into the mechanically-operated dip net the depth values in the table states the net depth before attaching to the frame the depth measurement – the center mesh of the bottom is taken the net is slightly stretched and aligned so perimeter mesh is on the same level the net is laid taut on the rule and measured the table values are approximate and may differ slightly in same type of nets the sizes are in cm

Composition: - hand-made net made from PA cord (3mm diameter) - bottom row of the net is doubled with attached metal rings - net is attached to a metal frame with a long wooden handle

RING DIAMETER NET DEPTH MESH SIZE CORD THICKNESS (in cm) (in cm) (in mm) (in mm) 100 100 25 3 The depth measurement of machine-made net, net sewed by hand

10 Overview of handling nets

the nets made for hand nets, dip nets, fry dip nets and landing MESH HAND THE NET TYPE DEPTH DIP FRY DIP LANDING nets differ in their design, materials used and usage SIZE NET NET NET NET

the table shows the compatibility of nets and frames 15 45 / 50 / 55 / 60 – – Hand-made net from plaited cord 20 45 / 50 / 55 / 60 – – Hand-made net long-life net (Hand net, Dip net) suitable for handling large fish 25 45 / 50 / 55 / 60 – – suitable for hand net and dip net frames mesh 15 mm, cord thickness 1.8 mm 30 45 / 50 / 55 / 60 – – mesh 20 mm, cord thickness 2.0 mm mesh 25 mm, cord thickness 2.0 mm mesh 30 mm, cord thickness 2.5 mm 4 40 / 45 / 50 –

6 45 / 50 / 55/ 60 – Machine-made net (hand net, dip net, fry dip net) from machine knotless net Mounted & sewn from the machine- 15 45 / 50 / 55 / 60 – – harmless to handled fish made net suitable for all sizes of fish (Hand net, Dip net, 20 45 / 50 / 55 / 60 – – mesh size 4 – 30 mm Fry dip net) the net thickness corresponds to mesh size 25 45 / 50 / 55 / 60 – –

Sewn from the machine-made net 30 45 / 50 / 55 / 60 – – (dip net, fry dip net) from machine knotless net harmless to handled fish 4 20 – – suitable for small sizes of fish Sewn from the mesh size 4 – 10 mm machine-made net 6 30 – – the thread thickness corresponds to mesh size (Dip net) 10 30 – – Hand-made net (landing net) from plaited cord 15 50 / 100 – – – long-life net suitable for handling large fish Mounted & sewn 20 50 / 100 – – – mesh size 25 mm, the cord thickness 2.5 mm from the machine- mesh size 30 mm, the cord thickness 2.5 mm made net (Landing net) 25 50 / 100 – – –

Machine-made net (landing net) 30 50 / 100 – – – from machine knotless net 25 50 / 100 – – – harmless to handled fish Hand-made net suitable for all fish sizes (Landing net) mesh size 10 - 30 mm 30 50 / 100 – – – the thread thickness corresponds to mesh size

11 Fry dip nets

used for careful handling of fry, small cone-shaped handle fish species and plankton diameter 28–35 mm

cylindrical handle Fry dip nets are made diameter 32 mm in the following shapes: fry dip net handle rectangular diameter 28 mm circular

Nets for fry dip nets are made of various materials and mesh sizes: material used is fabric from either PA or PES strands mesh size is precise available in mesh sizes: 0.04, 0.1, 0.14, 0.2, 0.24, 0.34, Handles 0.5, 0.6, 2 mm net – mesh 3, 4 mm For handling equipment the mesh strands are fixed tightly to prevent displacement made from ash or beech wood Fry dip nets are sold only as sets – frame + net suitable for hand net, dip net, fry dip net and landing net

Sizes:

Cone-shaped handle for hand net and dip net Cone-shaped handle for landing net - the beginning cone-shaped 28 mm in diameter - the beginning cone-shaped, diameter 28 mm - from the end of the socket diameter 35 mm - from the end of the socket diameter 35 mm - the lengths 90, 110, 150 and 180 cm - the length 180 cm

The cylindrical handle for hand net and dip net The cylindrical handle for landing net - diameter 32 mm in all length - the beginning straight, 32 mm diameter - the ending is not shaped - diameter 35 mm in all length - the lengths 90, 110, 150 and 180 cm - the length 180 cm

The cylindrical handle for fry dip net and plankton net - 28 mm diameter in all length - Lengths 150 / 180 cm We can attach a new net to your old frame

12 Fry dip nets are sold only as sets – frame + net

doubled lower part of the frame – prevents damaging the net

Channel fry dip net Fry dip net – circular net Fry dip net – rectangular it is used for careful manipulation of all kinds It is used for catching and handling of small it is used for catching and handling of small of fish fry and as well as with plankton fish, ornamental fish and fry from all species fish, ornamental fish and fry from all species attached to a frame by polyamide firm fabric net is attached to a frame by polyamide firm Usage: - in every hatchery which prevents damaging the net fabric which prevents damaging the net - handling freshly hatched fry of all kinds of fish - small fish handling Usage: Usage: - in a hatchery - in a hatchery Sizes: - raising freshly hatched fry of all kinds of fish - raising freshly hatched fry of all kinds of fish - frame 25 x 15 cm - handling small fish species - handling small fish species - depth 20 cm - catching and handling plankton - catching and handling plankton - wire diameter 4 mm - doubled lower part of the frame – prevents damaging Sizes: Sizes: the net - circle diameter 40 cm - 25 x 40 cm - metallized coating (electroplating) - depth 30 cm - depth 20 cm - handle is part of the frame – length 30 cm - wire diameter 8 mm - wire diameter 8 mm - it is not mounted to a wooden handle ! - tube-shaped socket 10 cm long - tube-shaped socket 10 cm long - metallized coating (electroplating) - metallized coating (electroplating) Types of nets used: - handle diameter 2.8 cm - handle diameter 2.8 cm - material used is fabric from either PA or PES strands - mesh size is precise Types of nets used: Types of nets used: - available in mesh sizes: 0.04, 0.1, 0.14, 0.2, 0.24, 0.34, - material used is fabric from either PA or PES strands - material used is fabric from either PA or PES strands 0.5, 0.6, 2 mm - mesh size is precise - mesh size is precise - net – mesh 3, 4 mm - available in mesh sizes: 0.04, 0.1, 0.14, 0.2, 0.24, 0.34, - available in mesh sizes: 0.04, 0.1, 0.14, 0.2, 0.24, 0.34, 0.5, 0.6, 2 mm 0.5, 0.6, 2 mm - net – mesh 3, 4 mm - net – mesh 3, 4 mm 13 Plankton nets

14 Plankton nets Usage: plankton and fish fry sampling of all species and sizes catching plankton for feeding fish fry of all species catching plankton from shore and boat

Types of plankton nets: Plankton cast net – net is attached to a metal frame and supplemented by a cord reel Apstein plankton net – net is attached to a cone-shaped metal frame by tightening – used for vertical sampling of plankton Closable Apstein plankton net – similar to a cast net – used for plankton sampling at chosen depths Plankton tow net – net is attached to large metal frame and usually towed by a boat Static drift net – net is attached to a frame and installed into the current Benthic dip net – net is attached to a metal frame equipped with a handle Plankton static net – without frame to support, this net is attached to outflow tubes from ponds

Composition: fabric made from PA or PES threads precise mesh size mesh size 0.01, 0.02, 0.04, 0.1, 0.14, 0.2, 0.24, 0.34, 0.5, 0.6, 2 mm the mesh threads are fixed tightly to prevent displacement the upper edge of the net is made from firm PA or PES fabric to avoid damage possible to attach the net to a frame, depending on its usage the net can be attached to a frame and reinforced with additional strands when necessary the nets do not decay disinfectants do not harm the materials used

All nets in this section are made from the following materials: UHELON ® NITEX ® TYL ®

products marked by this sign are also suitable for scientific research

15 Plankton dip net sampling plankton catching plankton for feeding purposes catching plankton near the water surface catching plankton from shore or boat

Design: net is attached to a circular frame with a handle possible to use nets of various mesh sizes

fry dip net handle diameter 28 mm Sizes:

Materials used for plankton sampling - circular frame diameter 20 cm - wire diameter 6 mm - metallized coating (electroplating) - the height of protective hem 5 cm - the net depth 30 cm U-shaped net - V-shaped net - the length of handle 150 or 180 cm the same width in upper and lower part the advantage of this shape is high efficiency Plankton net used for large mass plankton - larger sampling surface of the net catch for feeding - small escape of the plankton – net does not “wash itself out” - circular frame diameter 40 cm - wire diameter 8 mm the disadvantage is that it is difficult to empty the net - metallized coating (electroplating) - the height of protective hem 5 cm - the net depth 70 cm V-shaped net - V- or U-shaped net - the length of handle 150 or 180 cm the net narrows towards the bottom – the bottom width is 10 cm - the bottom has half-circle shape FRAME DIAMETER WIRE DIAMETER MESH SIZE THE NET DEPTH the advantage is that the shape of the net easily facilitates (in cm) (in mm) (in mm) (in cm) 0.01, 0.02, 0.04, 0.1, emptying 20 6 30 - the catch at the bottom of the net is reversed into a prepared con- 0.14, 0.2, 0.24, 0.34 0.01, 0.02, 0.04, 0.1, tainer 40 8 70 the disadvantage is lower catching efficiency 0.14, 0.2, 0.24, 0.34 We can attach new nets onto old frames made by our company.

16 Plankton cast net essential tool for plankton sampling Cast net bag Usage: Sizes: is an essential supplement for the catching all plankton species and sizes circular frame diameter 20, 30 and 40 cm sampling in vertical and horizontal direction of water wire diameter 6, 8 mm plankton cast net column the net depth 40, 50, 60 cm Usage: sampling from shore or boat mesh size – 0.01, 0.02, 0.04, 0.1, 0.14, 0.2, 0.24, 0.34 mm casing and protecting the plankton cast net the protective hem height 5 cm comfortable carrying of the net in the field Design: 30 m cord reel with cord of diameter 3 mm carrying sampling containers and catches circular frame made from steel wire net has an outlet tap circular frame is supplemented with 3 binding rings Design: possible to attach nets of various mesh sizes to the frame cast net bag is made from breathable PA fabric, plankton cast net is supplemented by a cord reel with which dries fast diameter 3 mm beg is equipped with arm belt net has an outlet tap bag is equipped with inner pocket for samples, tap serves as a weight for casting the net or lowering notes etc. down the net possible to equip the net with additional weight for vertical sampling SIZES 25 x 25 cm FRAME DIAMETER / MESH SIZE PROTECTIVE HEM HEIGHT THE CORD REEL CAPACITY 35 x 35 cm NET DEPTH (in cm) (in mm) (in cm) (in m) 45 x 45 cm 0.01, 0.02, 0.04, 0.1, 0.14, 20/40; 30/50; 40/ 60 5 30 0.2, 0.24, 0.34

17 vertical haul with plankton net horizontal haul with plankton net

18 Apstein plankton net RNDr. Jiří Macháček, CSc. senior scientist of Institute of Hydrobiology, cone-shaped metal frame reduces BC AS CR, v.v.i., České Budějovice turbulence in front of the net zooplankton research zooplankton sampling in the Římov Reservoir net surface is larger than the plankton cast net [email protected] Usage: used for plankton abundance assessment in water column used only for vertical sampling

Design of standard Apstein plankton net net is attached on a firm metal cone-shaped frame the entrance edge of the net has a doubled fabric hem the hem includes cord to attach the net to the frame the outlet has an outlet tap combining nets into sets possible outlet tap serves as the weight for lowering the net providing tap with additional weight possible

Standard sizes: metal frame: - upper diameter 20.5 cm - lower diameter 39 cm - height 40 cm net: - net height 73 cm - hem height 4.5 cm - mesh size 0.04, 0.1, 0.14, 0.2, 0.24, 0.34, 0.5

Standard sizes MESH SIZES HEIGHT NET DIAMETER NET DEPTH (in mm) (in cm) (in cm) (in cm) 0.04, 0.1, 0.14, 0.2, 0.24, 0.34, 0.5 113 39 73

19 Usage of Apstein plankton net Difference between standard and closable (Seďa's modification)

Standard Apstein plankton net

Closable Apstein plankton net – new field design (Seďa's modification)

Advantages of closable Apstein plankton net easy to transport and store easy sampling manipulation sampling in targeted depth water column only Closable Apstein plankton net (Seďa's modification) possible to close the mouth of the net at the targeted depth

Design: the upper edge of the cone-shaped net has a circular frame with 3 binding rings cone-shaped inlet piece is made from fabric cone-shaped inlet can be closed at the targeted depth binding rings making net closable at the targeted depth are available at request this design is suitable for sampling several depth layers separately possible to make also non-closable Apstein net the net is made from polyamide - PA fabric of precise mesh size the outlet has an outlet tap outlet tap serves as the weight for lowering the net providing tap with additional weight for vertical sampling possible

Instructions for use: used for vertical sampling only net is lowered into targeted depth net is evenly pulled from depth the haul is performed with cord attached to circular frame net includes 3 tightening rings to close net at targeted depth net is closed by pulling the colored cord passed through rings the net is then hauled to the boat with colored drawstring white cords stays loosened

Standard sizes WIRE THICKNESS CIRCULAR FRAME HEIGHT OF CONE-SHAPED EDGE NET DIAMETER NET DEPTH MESH SIZES CLOSABLE (in mm) DIAMETER (in cm) (in mm) (in cm) (in cm) 12 30 55 50 105 yes 12 40 55 70 105 yes 0.04, 0.1, 0.14, 0.2, 12 20 38 30 62 no 0.24, 0.34, 0.5 12 25 42 38 62 no 12 33 40 55 85 no

20 Instructions for use of closable Apstein net (Seďa's modification) RNDr. Jaromír Seďa Ph.D. - unfold the net zoologist, ecologist, hydrobiologist; senior scientist of - net is lowered into targeted depth – read depth from marked cord Institute of Hydrobiology, BC AS CR, v.v.i. - make haul in depth range of interest zooplankton research specialist - close the net by pulling drawstring in the targeted depth i am specialized in study of hybrids of gender Daphnia, - haul the net with colored drawstring from water their distribution and conditions determining their - loosen the drawstring above the water level presence. These hybrids are distinguished only by - wash down the catch to the outlet tap biochemical tests. - open the outlet tap and wash the catch into the container [email protected]

21 Outlet end Outlet end

measure measure

Fold it over Fold it over

Tie up Tie up Plankton tow net Static drift net the net is usually towed by a boat Usage: sampling of benthic organisms in lotic waters Usage: sampling of drifting fish catching large plankton masses disturb bottom sampling of fish fry Instructions for use: net is installed tilted against the water current Design: disturbance of the bottom in front of the static drift circular frame is made from steel wire net lift organism into the current circular frame is supplemented with 3 binding rings drifting organisms are caught in the net possible to attach various mesh sizes to a frame the catch is removed from the outlet end possible to divide the net in several mesh sizes to provide better water permeability Net design: - larger mesh at the beginning and smaller at the end Net is usually rectangular in shape of the net Inlet edge has a firm protective hem net is made with outlet end - Dismountable frame is threaded through the hem possible to attach a collecting container at the - The edge has tightening rings for attaching net to a frame end of net (it is not component of the net) Net has an outlet end

Sizes: Frame design: circular frame diameter 90 cm dismountable frame is usually made from square wire diameter 8 mm tubes 20 x 20 mm mesh sizes: 0.04, 0.1, 0.14, 0.20, 0.24, 0.34, 0.5, 2 mm frame has tightening rings or struts protective hem height 10 cm Sizes: recommended depth 2 or 3 m width 0.5 m, height 1 m 3 binding rings with tow harness of diameter 6 mm mesh sizes: 0.34, 0.5, 2.0 mm Outlet end – length 30 cm protective hem height 10 cm depth usually 1.5 m outlet end 40 cm long

Diameter, length and size of the net are adjusted to the customer's needs. 22 Outlet end Scheme of net attachment

handle Attached with cord Attached with measure diameter 32 mm hose clamp

bottom cover protects net from damage

Fold it over

Tie up Benthic dip net Plankton static net Usage: catching large plankton masses sampling benthic organisms in lotic waters – streams and rivers Usage: sampling benthic organism living in muddy substrate installed into places with large current and large amount of plankton of lentic waters – ponds, pools and lakes installed into outlet piping overflows etc. possible to draw water containing plankton into the net Instructions for use: net is towed on the bottom and benthic organisms Design: are sampled net has elongated cylindrical shape net is held perpendicularly to the bottom and inlet has a firm protective hem disturbance of the bottom in front of benthic dip net - draw tape is used for attaching net lift the organism into the current - the inlet edge supplemented with tightening rings for net attachment net is burrowed into the soft bottom and organisms the net has an outlet end are sampled by horizontal haul Instructions for use: Net design: net is installed into the water current, which carries plankton mesh size 0.34, 0.4, 0.5, 0.6 installation into outlet pipes, pumps, overflows etc. net width 40 cm, height 60 cm, depth 60 cm water flows through the net and plankton is caught protective bottom cover from PVC 40 x 60 cm mesh size determines the size of plankton caught the edge of the net has a firm protective hem made from PVC it is recommended to have a net 2 m or longer the bottom is protected against damage by bottom cover made from PVC the advantages of a long net: will not clog; plankton stays alive and will not washed out frame is sewn into PVC protective hem Sizes: the hem height is 10 cm net diameter 30 cm Frame design: length 2, 3 or 4 m wire diameter 10 mm mesh sizes: 0.04, 0.1, 0.14, 0.20, 0.24, 0.34, 0.5 and 2 mm frame width 40 cm, height 60 cm protective hem height 20 cm + tightening rings with diameter 8 mm handle diameter 32 mm, length 1.5 or 1.8 m protective hem height 20 cm + full hem with firm edge + draw metallic tape outlet end with length 40 cm

Diameter, length and size of the net are adjusted to the customer's needs. Diameter and length of the net is adjusted to the customer's needs. 23 Fish are sampled by active net movement in water column Active fishing gear Beach seine net

24 Beach seine net composition Floats the construction is adjusted to the shape and size of the beach seine net floats are attached to the upper line of the net various sizes and shapes of beach seine net are available they have various load bearing capacities related to their size float spacing depends on the net type and size colored floats mark the center of the net colored floats also mark the change in net height Heavy brace used for pulling the rope attachment joins upper and lower line to the pole heavy braces consist of 3 ropes Core of the net the end of the braces have a sling for pulling the core of the net is made from strips of the same height rope attachment - the net is slack similarly in whole length heavy brace is part of the heavy pole the core of the net is made from several strips with unequal height - the net is slack mostly in the middle (the broadened part of the net)

Wooden poles at the edge of the net used for hauling the net into a the core stripe of the net can vertical position contract to 2/3 of normal height at the end of the net allows for control of net depth expand the net at the edges

HEAVY DESIGN pole is sewn into the net (used for heavy beach seine net)

Net attachment NET ATTACHMENT – LIGHT NET ATTACHMENT – HEAVY Slings BEACH SEINE NET BEACH SEINE NET one or more pulling ropes net is threaded around its net is strengthened around its attachments perimeter perimeter Light pole insertion Lead line sewn directly to ropes with net has one or two rows of LIGHT DESIGN lead line is attached to the buoyancy and lead line larger mesh made from thicker pole is inserted into slings lower line of the net string (used for light beach seine net) consists of lead weights and a machine made net uses weights: 30, 80, 120, 160, 200 g/m

25 Beach seine nets Beach seine net division according to their shape and structure

used for active fishing in ponds, rivers, reservoirs beach seine nets differ in shape, construction, size and usage and other not drained water bodies beach seine net samples fish near the shore

Fish are sampled – caught by hauling the net from one or both ends

Usage: fishing in non-drained ponds, reservoirs, lakes, rivers etc. removing part of fish stock from non-drained ponds Beach seine net obtaining samples of fish – without bag – one-depth Advantages: Design: Advantages: quick flexible usage where needed the core of the beach seine net is made it is possible to haul the net asymmetri- ease of use with low demand of manpower (minimum 2 – 4 fishermen) from one strip of net with constant height cally effective fishing the strip is narrowed at the net edges to it is possible to haul the net from just caught fish suffer minimal damage requested height one side possible to control amount of fish caught it is easier to regulate amount of fish Usage: caught Design: fry beach seine nets PA – polyamide, PES – polyester knotless net with square or diamond-shaped small beach seine nets – fishing for Disadvantages: mesh small amount of fish lower fishing efficiency mesh size: 2 - 30 mm large beach seine nets without bag long and high nets are heavier than thread diameter: 0.01 – 1.4 mm (technical specification 210/4 – 210/27, see used when symmetrical haul is not beach seine nets with bag details of net swatch) possible without bag – one-depth net – net has uniform depth on its all length with bag – two(three)-depth net – net has deeper core the upper line has floats the lower line has lead line attached

26 Beach seine net division according to their design

Beach seine net – light design convenient for fishing small amounts of fish net is not strengthened with one or two rows of larger mesh on perimeter one-depth and two-depths designs are available Beach seine net – with bag length usually up to 50 m and height up to 4 m – multiple-depths spacing distance between floats 60 – 100 cm lead line weights 80 – 200 g/m Design: Advantages: usual ending: free ends, light brace, slings, light pole the net is made from 3 - 5 net strips of various heights lower net weight inserted into slings strip in the middle of the net is widened, making the bag high efficiency – minimal amount of fish escape during heavy brace with heavy pole is only suitable for short bag is placed symmetrically in the center of the net hauls beach seine nets edges – the strips are narrowed at the requested depth fish are concentrated in the bag when the beach seine net is hauled close to the shore Usage of multiple-depth beach seine net: small beach seine nets Disadvantages: – fishing for large amounts of fish it is necessary to haul the net symmetrically to the shore large beach seine nets it is necessary to reach the shore with center of the net – fishing for large amounts of large fish fishing out majority of fish stock

Beach seine net – heavy design convenient for fishing large amounts of fish net is strengthened with one or two rows of larger mesh on perimeter one-, two- and three-depth designs are available length range 10 – 300 m, net height more than 4 m spacing distance between floats 60 – 80 cm thirds and center of the net is marked with colored floats lead line 160 – 260 g/m usual ending light brace without pole heavy brace with pole is not suitable for long ad high beach seine nets

27 Beach seine net division according to its ending the rope is inserted into the net and creates the net ending the core strip of the net can contract to 2/3 of normal height at the end of the net contraction creates a cavity, which prevents fish from escaping during haul

Several possible endings for beach seine nets are displayed here. Customers may choose the ending according to their needs.

Free ending rope is free from buoyancy and lead line Simple brace in chosen length rope leading from buoyancy line and leading free ending gives customers the line is knotted in requested length into sling opportunity to adjust the ropes according pulling rope is attached to the sling to their specific needs

Slings – light pole Heavy brace with pole rope leading from buoyancy line, lead line rope leading from buoyancy and leading line and side of the net is knotted to a sling is modified into heavy brace (made from 3 possible to attach pulling rope to slings ropes) possible to insert wooden pole into slings pole is attached to the side of the net – combination of light pole and pulling rope it is not possible to detach the pole pole is used to lead the net during hauls pole is used for leading the net during haul – it expands the net at the edges pole expands the net during haul

28 Principles for successful beach seine net usage

Pressing lead line to the bottom Principles of beach seine net usage: haul – movement of the net through water is performed by people – fishermen, vehicle, boat or their combination net moves through the water column and catches fish fish are gathered in the net during the haul net creates a cavity during haul – “net core”, where fish are accumulated after haul ends redundant net is folded on boat or shore after haul is finished fish manipulation in the net should take place in deeper water – to protect fish from damage beach seine net is not used for pulling fish on the shore or boat, or other manipulation with fish fish are transported from the net only with handling equipment: hand net, dip net, fry dip net – according to fish size by foot by kneeling fisherman

Choosing suitable locality for haul: gentle slope of the bank structures-free bottom – stones, stumps, building remainders bottom should be firm - not muddy

Haul technique: haul is performed where fish are present haul is performed in area suitable for beach seine fishing fold the beach seine net before haul - fold buoyancy line on one side - fold lead line on the opposite side - fold net between lines – net must not be crossed minimize noise before haul and during net casting preparation and net casting must be performed quickly net is usually cast from a boat powered by an engine, skulls or pole before casting, net is folded on boat to quicken casting nets larger than 30 m have marked thirds and net center with colored floats the style of haul is performed according to net length, uniformly without pause every stoppage during the haul leads to fish escaping lead line has to be pulled on the bottom during haul Recommendations: it is possible to add weight to lead line where needed it is necessary to keep lead line on the bottom near shore – otherwise large amounts of when hauling the beach seine net far from shore, weight down the net edges and fish can escape buoyancy line support with floats for more effective hauls pressing down the lead line is usually performed: the buoyancy and lead line do not get closer during the haul – the sampled area - by kneeling - fisherman kneel on the shore and pulls leading line on the bottom is larger - by foot – fisherman stands and pulls lead line under his foot

29 Hauling techniques:

symmetrical haul asymmetrical haul

Net height should not be lower than depth of the sampled area

30 haul shore – shore

haul water – water

haul shore – water 31 Beach seine Fry beach seine nets Used for fry and juvenile fish sampling nets for fisheries in lakes, reservoirs, ponds and slow moving rivers common net length – 10 or 20 m, height 2 or 3 m research and 2 mm mesh size (using 4 mm mesh in late summer possible)

Fry beach seine nets are suitable for sampling fish in near shore areas with gently sloped banks. The bottom must be common use free of structures (stones, stumps, branches, macrophytes). Beach seine nets are most effective on gravel, sandy and clay beaches. Haul technique: Mgr. Mojmír Vašek, Ph.D. (*1975) Casting a fry beach seine net I obtained my doc- casting from boat – in deeper sampling locations (fish disturbance minimalized) torate from the casting by wading – in shallow sampling locations Faculty of Science at the University of South Bohemia in České Budějovice. Since 2000 I have worked at the Insti- tute of Hydrobiol- ogy (Biology Cen- tre AS CR, v.v.i., Fish Ecology Unit). I have participated in several internships and have conducted field work in several European countries (Netherlands, Austria, Norway, Finland) and in Kenya. My focus is on freshwater ecosystem research, particularly fish ecology and trophic inter- Methods of hauls: actions in freshwater environments. I am author or water - water shore-shore co-author of more than 40 primary research articles Net is casted parallel to the shore and afterwards hauled Net is casted in half-circle from shore to shore so it published in a variety of notable scientific journals. by pulling ropes to the shore. closes the sampled area. [email protected] http://www.hbu.cas.cz/fishecu/

I used fry beach seine nets in the studies mentioned below:

t
Vašek, M., Kubečka, J., Matěna, J., Seďa, J., 2006. Distribution and diet of 0+ fish within a canyon-shaped European reservoir in late summer. International Review of Hydrobiology 91: 178–194. t
Jůza, T., Vašek, M., Kratochvíl, M., Blabolil, P., Čech, M., Draštík, V., Frouzová, J., Muška, M., Peterka, J., Prchalová, M., Říha, M., Tušer, M., Kubečka, J., 2014. Chaos and stability of age-0 fish assemblages in a temperate deep reservoir: unpredictable success and stable habitat use. Hydrobiologia 724: 217–234.

32 Haul is performed by 2 – 4 people distributed evenly on both ends of the beach seine net. Pressing lead line to the bottom is necessary during net hauling.

Advantages of a fry beach seine net: affordable easy to manipulate highly efficient in suitable sampling sites harmless to fish – does not cause damage simple catch evaluation easy to calculate abundance of fish occurring in littoral area of water body

33 Adult beach seine nets Beach seine net casting: Water-water beach seine nets are essential for sampling shallow littoral areas species and size selectivity of beach seine net is very low in both day the whole net is deployed at the targeted distance along the shoreline and hauled towards the shore and night the disadvantage of this technique is the large amount of fish escaping through beach seine nets are highly suitable for quantitative sampling the gaps between the net and shore beach seine nets provide real values about the amounts of most species and size categories in sampled areas beach seine nets 100 m or longer are effective tools for biomanipula- tion purposes

Usage: sampling of various species and sizes sampling in lakes, reservoirs, ponds and slow flowing rivers recommended length of 100 or 200 m with a minimum height of 4 m for hauling shore-shore recommended length of 50 m with a minimum height of 4 m for hauling water-water minimum net length 20 m Sampled area calculation 10 mm mesh size – fish one year old and older are usually not able to pass through the sampled area is the shape of a regular trapezoid with dimensions: this mesh size a = length of used net c = approximately 2/3 of used net d = casting distance from the shore

a + c Mgr. Milan Říha, Ph.D. The sampled area is then calculated area = x d I studied in the Faculty of Science at the University according to a formula: 2 of South Bohemia in České Budějovice and have worked at the Institute of Hydrobiology (Biology Centre AS CR, v.v.i., Fish Ecology Unit) since 2004. My research is conducted mainly in the Czech Republic and other European countries such as Austria, Spain, and the Netherlands. I have also conducted research in North America, particularly Puerto Rico and USA (fish distribution in Lake On- tario). My main research topics are fish distribution in freshwater ecosystems and research methodol- ogy – particularly the development and usage of active fishing gear (beach seine nets and trawls). I co-operate closely with the Pokorný-sítě company on their development. I have authored or co-authored 30 primary research articles that have been published in several high impact journals. [email protected] http://www.fishecu.cz/staff-members/riha/

34 Beach seine nets Shore - shore – used for both fry and adult fish sampling This technique is optimal for quantitative sampling. used for sampling – fry and smaller fish species (up to 10 cm) the net is cast in a rectangle from shore to shore – the net encloses the sampled area the sampled area depth must not exceed the height of the beach seine net used for species composition and abundance assessment under these conditions the net prevents fish from escaping Design the core stripe of the net can contract polyester net with mesh size 2 mm to 2/3 of normal height at the end of the net polyamide net with mesh size core height (in m) 4, 6 and 10 mm thread diameter 0.5 – 1.4 mm – (210/4 – 210/28) see table below for recommended lengths, heights and design light beach seine nets designed for field total length (in m) - 10 x 3 cm floats - Lead line 80 g/m Sampled area calculation the sampled area is rectangle-shaped or square-shaped the values needed for calculation: - length of the net casted parallel to the shore (a) For the maximum effectiveness of the beach - length of the net cast perpendicular to the shore (b) seine net, it is necessary to shrink the net edge to at least 2/3 from initial height. the calculation is based on the formula for the area of a rectangle (area = a * b)

Colored floats placed every ten meters help to measure lengths of cast net. We make beach seine nets in recommended and tested sizes It is possible to use the counting of floats during net casting to calculate the sampled for research institutes area. Light design – one-depth net after calculation, it is possible to compute the catch to the hectare or another MESH SIZE THREAD CORE HEIGHT RECOMMENDED LENGTH required area unit (in mm) THICKNESS (in m) (in m) more details about beach seine net usage are found in Říha et al. (2008) and Kubečka 2 Tyl (PES) 2, 3, 6 10- 30 et al. (2010). http://www.fishecu.cz/staff-members/riha/ 4 210/4 2, 3, 4 10 - 30

6 210/6 2, 3, 4 10 - 50

10 210/14 2, 3, 4, 6 10 m and longer

Heavy design – one-depth net 6 210/6 2, 3, 4 10 - 50m

10 210/14 2, 3, 4, 6 10 m and longer

We make beach seine nets according to each customer's needs. We make beach seine nets with an extended bag. Any other adjustments according to the customer's needs also possible.

35 Standard beach Types:

seine nets Core height (in m) used for sampling all fish sizes and ages greater than 10 cm in length Total length (in m)

Material composition: One-depth beach seine nets has uniform depth throughout the length of the net polyamide knotless net mesh size 6, 10, 15, 20, 25 and 30 mm thread thickness 0.5 – 1.4 mm (210/6 – 210/27) see table for recommended lengths, heights and design Lengths of different net sections (in m) nets longer than 30 m have a marked center Core height (in m) nets longer than 60 m are marked in thirds colored floats marks the position beach seine nets have lead lines fitted to their size (80 – 240 g/m) Total length (in m)

For the maximum effectiveness of the beach The depth of panels in two-depth net increase usually twice towards the central panel seine net, it is necessary to shrink the net edge to at least 2/3 from initial height.

Lengths of different net sections (in m) Core height (in m)

Total length (in m)

The depth of panels in three-depth net increase usually twice towards the central panel.

Instructions for use

correctly choosing a beach seine net These recommendation are found at correctly using a beach seine net the beginning of chapter.

36 Beach seine net designs One-depth beach seine net uniform depth throughout its all length Heavy design Usage: universal shape for all types of hauls suitable for all water bodies with structures-free gently-sloped banks disadvantage may be increased weight in case of large nets = larger effort needed during haul disadvantage of small nets may be fish escaping during haul techniques such as water – water and shore - water Light design

Effective net endings: Less effective ending for longer nets and haul technique water - water: Composition polyamide knotless net mesh size 6, 10, 15, 20, 25, 30 mm thread thickness 0.5 – 1.4 mm (210/6 – 210/27) see table for recommended length, height and design nets longer than 30 m have a marked center free ends simple brace heavy brace slings, slings with nets longer than 60 m are marked in thirds light pole lead lines weight is based on the beach seine net size (80 – 240 g/m) Light design – one-depth beach seine net MESH SIZE THREAD NET HEIGHT RECOMMENDED For the maximum effectiveness of (in mm) THICKNESS (in m) LENGTH (in m) the beach seine net, it is necessary to shrink the net edge to at least 2/3 6 210/6 2, 3, 4 10 and longer from initial height. 10 210/18 2, 3, 4 10 and longer 15, 20, 25, 30 210/27 2, 3, 4 10 and longer

Heavy design – one-depth beach seine net MESH SIZE THREAD NET HEIGHT RECOMMENDED (in mm) THICKNESS (in m) LENGTH (in m) 6 210/6 2, 3, 4 10 and longer 10 210/18 2, 3, 4 10 and longer 15 210/27 2, 3, 4 10 and longer 20, 25 210/27 2, 3, 4, 6 and longer 10 and longer 30 210/27 2, 3, 4, 6 and longer 10 and longer

37 Two-depth beach seine nets the depth of panels in two-depth net increases usually twice towards the central panel core height Usage: the core stripe of the net useful shape for all kinds of hauls can contract to 2/3 of normal height haul needs to be symmetric to the center at the end of the net useful for all small water bodies the advantage is low weight the advantage is high efficiency – minimal escaping fish total length

Effective net endings: Less effective ending for longer nets and haul technique water - water:

free ends simple brace heavy brace slings, slings with light pole

Two-depth beach seine net – light design MESH SIZE (in mm) THREAD THICKNESS CORE HEIGHT (in m) LENGTHS OF DIFFERENT NET SECTIONS (in m) TOTAL LENGTH (in m) 1.5 3 1.5 10 / 15 / 20 / 25 210/14, 27 2 4 2 2.5 3 2.5 8 2.5 5 2.5 1.5 3 1.5 10 / 15 / 20 / 25 210/14, 27 2 4 2 3 4 3 10 2.5 5 2.5 1.5 3 1.5 10 / 15 / 20 / 25 210/14, 27 2 4 2 4 4 4 12 2.5 5 2.5 2 4 2 10 / 15 / 20 / 25 210/14, 27 2.5 5 2.5 5 6 5 16 3 6 3 2 4 2 10 / 15 / 20 / 25 210/14, 27 2.5 5 2.5 7 6 7 20 3 6 3

38 Three-depth beach seine nets – heavy design depth of the net sections have a ratio of 1 : 2 : 4 core height Usage: the core stripe of the net useful shape for all kinds of hauls can contract to 2/3 of normal height at the end of the net haul has to be symmetric to the center useful net for all large water bodies the advantage - low weight – possibility of using larger net - high efficiency – minimal escaping fish total length

Effective net endings: Inappropriate endings:

heavy brace for haul free ends simple brace technique shore - shore slings, slings with light pole

Three-depth beach seine net – heavy design

MESH SIZE (in mm) THREAD THICKNESS CORE HEIGHT (in m) LENGTHS OF DIFFERENT NET SECTIONS (in m) TOTAL LENGTH (in m) 2 4 6 4 2 25 / 30 210/27 3 6 12 6 3 10 10 20 10 10 60 4 8 16 8 4 2 4 6 4 2 25 / 30 210/27 3 6 12 6 3 10 20 30 20 10 90 4 8 16 8 4 2 4 6 4 2 25 / 30 210/27 3 6 12 6 3 20 20 40 20 20 120 4 8 16 8 4 2 4 6 4 2 25 / 30 210/27 3 6 12 6 3 25 30 50 30 25 160 4 8 16 8 4

We make beach seine nets according to each customer's needs. We make beach seine nets with an extended bag. Any other adjustments according to the customer's needs also possible.

39 Beach seine net fishing in a commercial pond

Instructions:

- clear the net out of debris before fishing and check the netting for holes - fold the net on the boat with floating line on one side, lead line on the other side, with the net core int he middle of the boat - fold both lines at once on the boat

net casts itself from a moving boat run by rowing or engine

after casting, a haul is performed by pulling floating and lead lines towards the shore

haul has to be continuous without interruptions - fish gather in the deepest part of the net, in the core - deeper core represents an advantage, as it is in three-depth beach seine net

after the haul the net is fold and fish are grouped to one place

fish catch is sorted and lifted on a special place

40 Dragnet designed for channels - channel dragnet Fishing effectively, quickly and carefully.

The channel dragnet is an effective tool requiring minimum effort.

Usage: for comfortable and careful fishing from raceways, concrete and natural channels for temporary and careful storing of fish

Advantages: pole inserted ease of use for 2 – 4 people into the sling high fishing efficiency – up to 90 % careful fish handling - harmless to fish keeping - storing fish with no other manipulation needed Channel dragnet – light design possible to transport fish from the net with fish Usage: pump fishing from ground channels, ponds, raceways temporary fish storage

Composition: polyamide knotless net mesh size 6, 10, 15, 20 mm thread thickness 0.5 – 1.4 mm (210/6 – 210/27) floats, lead line, slings see table for recommended lengths, heights and design light design

THREAD MESH SIZE (in mm) WIDTH (in m) HEIGHT (in m) DEPTH (in m) THICKNESS 6, 10, 15, 20 210/6 – 27 1, 2, 3, 4, 5, – x 0.5, 1, 1.5 1, 1.5, 2, 3

Developed for your fish We make channel dragnets according to each customer’s needs. farm by the Pokorný-Sítě We make channel dragnets with an extended bag. company. Any other adjustments according to the customer’s needs also possible.

41 Instructions for use:

1 - insert sufficiently long wooden poles into slings on the net ends 5 - haul starts on one side of channel and ends on the opposite side - fold the sling and insert the wooden pole as shown in the drawing - it is useful to end haul at the intake section - keeps caught fish in good condition

2 - adjust the net height according to channel depth

6 - after haul is done – quickly lift the lead line above the water level - channel dragnet can be used as live-box by placing poles across channel

3 - attach pulling rope to central sling

7 - remove fish with hand net, dip net or fish pump - possible to keep a reasonable amount of fish in the net for future sale or handling 4 - wooden poles are used to drag the net from the shore - possible to use a channel dragnet as a temporary life-box for fish storage a/ net draught regulation – regulation of amount of fish caught b/ lift the net to avoid filling the dragged net with mud

42 Instructions for use: Channel dragnet attach the net to the metal frame – designed for possible to mount wheels on the frame for easier manipulation channel dragnet is pushed through the channel from one side to the other concrete channels it is useful to end haul in the intake section of the channel - keep caught fish in good condition Usage: lift/recline the equipment after haul – fish will stay in the net fishing from concrete channels place metal frame flat on the concrete channel and use as life-box temporary fish storage possible to keep fish in the net for future manipulation remove fish with hand net, dip net or fish pump Composition: polyamide knotless net MESH SIZE THREAD WIDTH HEIGHT DEPTH (in mm) THICKNESS (in m) (in m) (in m) mesh size 6, 10, 15, 20 mm thread thickness 0.5 – 1.4 6, 10, 15, 20 210/6 – 36 1, 2, 3, 4, 5, – x 0.5, 1, 1.5 1, 1.5, 2, 3 (210/6 – 210/36) see table for recommended lengths, heights and design We make channel dragnets according to each customer’s needs. light design We make channel dragnets with an extended bag. Any other adjustments according to the customer’s needs also possible.

43 Bagnets and dragnets

44 Bagnets and dragnets These nets are short and deep – the main difference from beach seine nets. Usage: fishing from drained ponds and storage ponds actively fishing large amounts of fish in small water volumes vats lashing peg

inflow depth regulation of lead line using boathook enclosure

fishing spot depth regulation net hauling done using poles by people bridge for fish processing net hauling done by people

fishing spot scaring of fish scaring of fish lashing peg pond drainage vats

The principle is to catch fish while dragging the net through water with both ends

Design: The usage of a bagnet and dragnet: polyamide knotless net with diamond–shaped mesh haul – the movement of the net throughout water is done by individuals mesh size 6 – 30 mm net moves through the water column and catches fish thread thickness 1.4 – 2.5 mm (210/6 – 210/48) fish are accumulated in the net during haul net is sewn into the shape of a bag – “net core” net creates a bag where fish concentrate during haul perimeter is strengthened with two mesh rows made from thicker thread after the haul ends, the net is pulled to the boat upper and lower part of the net is threaded through with thick plaited ropes net is pulled to the boat with caution to avoid damaging fish net has a buoyancy line with floats bagnet and dragnet are not used for lifting fish from water, or other fish manipulation net has a lead line fish are only removed with handling equipment – hand net, dip net, fry dip net – net ends haves sewn / attached wooden (or metal) poles according to fish size poles – used for hauling the net and net depth regulation net ends have a heavy brace to which the pulling rope is attached Net depth is regulated with boathook and poles

45 Function of boathook and poles during bagnet and dragnet usage

regulation of net depth end the haul near vats

regulation of net depth

tie lead line to the lashing pegs and pull buoyancy line net should be dragged on the bottom! and the bag to the vats

raised net means haul the net slightly net hauled through the escaped fish above the bottom bottom results in catching mud instead of fish

open the net, fold the redundant net and remove the fish

concentrating the fish in the bag and removing the fish until the net is empty

46 specially designed boathook in a shape of “pig tail”

Boathook for bagnet and dragnet depth regulation Poles Usage: - regulates the depth of the lead line during haul accessories for beach seine nets, bagnets and dragnets - prevents taking up mud into the net - helps to more easily catch fish in the net made from hard wood or metal Wooden pole of adequate length is inserted into Usage: metal hook socket. - controlling the net during haul - net depth regulation during haul

Large wooden pole Small wooden pole Metal pole Usage: Usage: Usage: - large dragnets - beach seine nets, bagnets, - bagnets and dragnets exclusively dragnets used in storage ponds Sizes: - part above the net is narrowed for Sizes: Sizes: easier hand grip - part above the net is narrowed for - equally thick throughout its length - diameter of lower part 50 mm, easier hand grip - metallized coating (electroplating) diameter of upper part 40 mm - diameter of lower part 48 mm, - diameter 38 mm - total height 180 cm diameter of upper part 36 mm - total length 140 cm - 90 cm height above the net - total height 140 cm - 75 cm height above the net - 90 cm height above the net

47 Bagnets and dragnets composition

Bagnets and dragnets are both strengthened along their Floats perimeter. floats are attached to the upper line of the net they have various load bearing capacities related to their size float spacing depends on the net type and size Description of strengthening: uses thicker string than for the net mesh size is always larger than mesh size of the net usual mesh size is 3 cm (first row) and 4 cm (second row) Bagnet design string is threaded through mesh rows short net with bag upper line has floats bag depth is 1 : 3 of the width lower line has sewn weights Bagnet

Dragnet design bag depth may be equal to net width, i.e. 1:1 bag is square or rectangle-shaped with beveled sides beveling of the bag starts at 1/3 or 1/2 or 2/3 of bag depth

Lead line lead line is attached to the lower line of the net net endings are attached to wooden poles consists of lead net is fastened to the pole with string weights and a net ending is a heavy sling made machine made net from three ropes – heavy brace Dragnet uses weights: 30, 80, 120, 160, 200 g

NET ATTACHMENT – HEAVY DESIGN net is strengthened around its perimeter net has one or two rows of larger mesh made from thicker string

48 Bagnet

fishing from drained ponds and storage ponds actively bag depth fishing large amounts of fish from a small volume of water BAGNET Design: short net with bag useful in drained ponds, fish storage ponds, channels bag depth is at most 1/3 of the width (e.g. 3 m width, 1 m depth) width bag tapers to an equilateral trapezoid shape

Standardly made sizes of bagnets MESH SIZE (in mm) THREAD THICKNESS SIZE – WIDTH X DEPTH (in m) MEASURING UNIT 6 210/6 3 x 1 / 6 x 2 / 8 x 2 / 10 x 2 / 10 x 3 piece 10 210/18 3 x 1 / 6 x 2 / 8 x 2 / 10 x 2 / 10 x 3 piece 15 210/27; 210/36 3 x 1 / 6 x 2 / 8 x 2 / 10 x 2 / 10 x 3 / 12 x 4 / 15 x 5 piece 20 210/27; 210/36 3 x 1 / 6 x 2 / 8 x 2 / 10 x 2 / 10 x 3 / 12 x 4 / 15 x 5 piece 25 210/27; 210/36 6 x 2 / 8 x 2 / 10 x 2 / 10 x 3 / 12 x 4 / 15 x 5 piece 30 210/27; 210/36 6 x 2 / 8 x 2 / 10 x 2 / 10 x 3 / 12 x 4 / 15 x 5 piece

49 Dragnet

fishing from drained ponds and storage ponds actively bag depth fishing large amounts of fish from a small volume of water

Design: short net with deep bag DRAGNET useful in drained ponds, fish storage ponds, channels bag depth may be equal to net width, i.e. 1:1 (e.g. net width 3 m, bag depth 3m) beware dragnets with large depth – danger of oxygen depletion and mechanical width damage of fish during removal bag is square or rectangle-shaped with beveled sides bevel options can be 1/3 or 1/2 or 2/3 of bag depth (see also figure) Design of Dragnet is useful in fish storage ponds beveling determines possible amount of fish caught using a small width, you can achieve a large depth, possibly catching a large amount of fish in a limited space Standard sizes of dragnets MESH SIZE (in mm) THREAD THICKNESS SIZE – WIDTH X DEPTH (in m) UNIT OF MEASURE 6 210/6 3 x 2 / 5 x 4 / 6 x 3 / 8 x 3 / 10 x 4 piece 10 210/18 3 x 2 / 6 x 3 / 6 x 4 / 8 x 3 /8 x 4 / 10 x 5 piece 15 210/36; 210/48 5 x 3 / 5 x 4 / 6 x 3 / 6 x 4 / 6 x 5 / 8 x 4 / 10 x 5 / 12 x 7 / 15 x 7 piece 20 210/36; 210/48 5 x 3 / 5 x 4 / 6 x 3 / 6 x 4 / 7 x 4 / 8 x 4 / 10 x 5 / 12 x 7 / 15 x 7 / 15 x 10 / 25 x 10 piece 25 210/36; 210/48 5 x 3 / 5 x 4 / 6 x 3 / 6 x 4 / 7 x 4 / 8 x 4 / 10 x 5 / 12 x 7 / 15 x7 / 15 x 10 / 25 x 10 piece 30 210/36; 210/48 5 x 3 / 5 x 4 / 6x3 / 6 x 4 / 7 x 4 / 8 x 4 / 10 x 5 / 12 x 7 / 15 x 7 / 15 x 10 / 25 x 10 / 30 x15 piece

50 Fishing out the pond using dragnet

enclosure and fish scaring preparation for haul haul

hauling the net to the vats attachment of lead line to lashing pegs concentrating the fish in a bag

concentrating the fish in a bag removing fish from the net fish sorting

51 Purse seine net

Purse seine net are also suitable for scientific research 52 RNDr. Jiří Peterka, Ph.D. (*1975) Purse seine net I obtained my doctorate in zoology from the Faculty of Science at the University of South Bohemia in České Budějovice. I worked as a research assistant at the Institute of Hydrobiology (Biology Centre AS CR, v.v.i., Fish Ecology Unit) during Sampling with purse seine net is based my studies. Since 2013 I have been the head of the Department of Fish and Zo- oplankton Ecology. I am also a council member of the institute of Hydrobiology. on encircling fish in the open water and My main research topics are succession of fish communities in post-mining capturing them. lakes, research of intra- and inter-specific competition (especially competition of our most important families – Cyprinidae and Percidae) and occurrence and behavior of fish in open water habitats. I use direct observation techniques and Usage: verify their results using active and passive sampling methods. I teach Marine sampling in open water biology and Marine biology field course at the Faculty of Science. I am also sampling all fish sizes supervisor of bachelor, diploma and doctoral theses. I am an author or co-au- whole sampling takes place in open water, thor of more than 30 primary research articles published in a variety of notable net is not dragged to the shore scientific journals, treatises, reports and chapters in the professional literature. [email protected] tel.: +420 387 775 854 Six rules for successful sampling: http://www.fishecu.cz/staff-members/peterka/ adequate fish presence in sampled area net of appropriate size Sampling with purse seine net is used mostly in marine fisheries. The following studies show the possibilities net correctly folded in the boat of purse seine net use in lentic waters (Tischler et al. 2000, Říha et al. 2012, Muška et al. 2013). fast speed during net casting net correctly closes the encircled space References: quick tightening of drawstring t
Tischler, G., Gassner, H. & Wanzenböck, J. 2000. Sampling characteristics of two methods for capturing age-0 fish in pelagic lake habitats. Journal of Fish Biology 57: 1474-1487 Advantages of purse seine net: t
Říha M., Jůza T., Prchalová M., Mrkvička T., Čech M., Draštík V., Muška M., Kratochvíl M., Peterka J., Tušer M., Vašek M., Kubečka J. 2012. The flexible use size selectivity of the main body of a sampling pelagic pair trawl in freshwater reservoirs during the night. Fisheries Research 127– 128. 56– 60 possible to catch fish shoal found by acoustics t
Muška M., Tušer M., Frouzová J., Draštík V., Čech M., Jůza T., Kratochvíl M., Mrkvička T., Peterka J., Prchalová M., Říha M., Vašek M., Kubečka anywhere in the open water J. (2013). To migrate, or not to migrate: partial diel horizontal migration of fish in a temperate freshwater reservoir. Hydrobiologia 707: 17-28. high efficiency easy to use - short initial training possible to gain complex experience

53 Instructions for use:

Choosing the right sampling spot Boat preparation - sufficient depth in sampled area - suitable boat – the best choice is a type AKV 001/10 boat developed by - sampled area should be without any fixed or floating structures members of FishEcU - fish should be present – find fish with echo sounder - boat characteristics – narrow, stable, sufficiently spacious and load-bearing - sampling for scientific research should be conducted in representative locations - the boat should be without projections, flashes, knots, floats, or clutter on the and follow a proper sampling design bottom (branches, stones etc.) - the engine should be sufficiently strong and properly mounted to the boat

54 Net preparation - clean the net of all litter (grass, branches etc.), sew all holes in the net - coil the colored drawstring threaded through rings up at the bow - place the drawstring with drawstring rings on the lower line at the bow - coil buoyancy line at the stern - fold the net core between the buoyancy and lead lines - net is folded simultaneously with buoyancy and lead lines - the net end which was folded last goes into the water first. this part has the smallest mesh – 6 mm.

Casting purse seine net - anchor on a suitable place using the anchor rope (cast the anchor / use an auxiliary boat) - the net is casted at fast speed by the auxiliary boat (the net needs to be anchored) - boat encircles the sampled fish shoal or sampled area - boat returns in the circle to the starting point of the cast - net is casted by the boat moving – crew intervention will lead to slower casting and to a smaller catch - the perimeter of the circle should be 10 % or 20 % larger than the net length – net ends are easily pulled together and this makes the subsequent haul easier - smaller perimeter than net length makes haul difficult to conduct

55 Net fully encircled the sampled area and sank to its maximum depth in the water column.

Boat is approximately on the same place where the haul started – fish shoal is in the en- circled area.

Join the lower lines of the net together immediately, attach additional weight if needed. Drawstring has to stay inwards (it must not be outside the cast- ed net). Organize the net on the boat as follows: Anchor the net core to the stern – it forms the outer part of overlapping nets. Anchor the end part with larg- er mesh to the aft – it forms the inner part of overlapping nets.

Pulling the drawstring leads to fast closing of the lower part of the net - fish are caught by closing the net under the fish shoal - tightened rings are pulled on the boat when 1/3 of floats are still on water - pull the rings from the water us- ing a crane with an electric reel that is part of the purse seine boat (type AKV001/10) - fold the net gradually on the boat

56 Place fish into floating live-box or vat on the second boat. Prepare the net for next fishing sample on the shore.

57 Purse seine net designed for research is available in two standard sizes: Boat designed for purse seine net Purse seine net for fry sampling Developed by members of Institute of Composition: Hydrobiology, BC AV CR v.v.i. in České shaped strip of PES – polyester knotless net Budějovice. 2 mm squared mesh the upper edge has floats The boat has patent protection (302159). the length is divided into quarters by colored floats – easy orientation during casting sides and lower line have drawstring rings Advantages: the drawstring is threaded through rings simple and highly efficient design high load bearing capacity Designed for fish fry: suitable on small water bodies where fry trawl cannot be used stable and fast useful accessories – crane, electric reel simple to attach and detach accessories MESH SIZE LENGTH HEIGHT MATERIAL (in mm) (in m) (in m) Composition PES 2 x 2 50, 80, 100 6 the boat is welded using duralumin sheets the boat has welded air chambers in the bow and stern the air chambers are used as a deck outrigger is included in the boat accessories - increases stability Purse seine net for adult and juvenile fish outrigger also increases load bearing capacity boat has crane and built-in electric reel Composition: electric reel is powered by the battery incorporated shaped strip of PA – polyamide knotless net into the outrigger diamond-shaped mesh with sizes 6, 8, 10 mm (thickness 210/4 – 9) electric reel has 12 V engine with a power output of 1000 W

Technical parameters of the boat length: 7.5 m width of main body: 1.6 m load bearing capacity: 1000 kg water displacement: 1 m3 crew capacity: 8 recommended engine power: 15 – 25 hp Designed for adult and juvenile fish: MESH SIZE LENGTH HEIGHT MATERIAL (in mm) (in m) (in m) Composition of 120 m length 6 mm – 210/4 30 m - mesh 6 mm Boat for purse seine net PA 8 mm – 210/4 12 45 m - mesh 8 mm is suitable for scientific 10 mm – 210/6 45 m - mesh 10 mm research

58 Boat designed for purse seine net

corner slant eases the casting of the buoyancy and upper part of the net corner slant is a part of the inner boat construction situated at the stern

Elongated bow used for placing the reel with the drawstring used for placing drawstring rings of the net Electric reel DRAWSTRING BOBBIN used for comfortable pulling of the used to reel the net drawstring drawstring used for drawstring casting during fast place two slings of a drawstring on casting of the net the reel prevents drawstring from entangling cast the drawstring by pulling gently the reel is controlled with the switch

Outrigger used to increase the stability of the boat during high speeds and net casting Folding arm of the crane easy to fold or detach the folding arm of the crane is fixed by one- outrigger for the transport side rope pulley Battery the drawstring is placed from the side of OUTRIGGER DECK used for powering the reel the pulley used for equipment storage during sampling batteries are stored in the outrigger used for pulling out the drawstring that made from thick PVC-coated cloth access to batteries via removable goes through rings attached to the net outrigger deck is stretched between the boat cover of the outrigger fix the crane with the straps before loading and the outrigger the cover protects batteries from the easy folding for transport and storage water

59 Representative sampling Trawl nets with a frame Bongo nets

Trawl nets are also suitable for scientific research

60 Frame trawls Msc. Tomáš Jůza Ph.D. (*5. 4. 1981) I completed my studies in the Faculty of Science at the University of South Bohemia in České Budějovice (2001 – 2011). Since 2007, I have worked in Institute of Hydrobiology – bongo nets of the Academy of Sciences of the Czech Republic. My main research interests are the ecology of fish fry in reservoirs and lakes, methodology of fish sampling and the universal net and sampling method efficiency of sampling gears. I have been on internships in the USA, Canada and Norway to learn about trawl sampling methodology. Currently, the challenge is evaluating the Usage: selectivity of trawls for various fish species and sizes living in the lentic waters. Frame sampling of invertebrates trawls, ichtyoplankton nets and bongo nets are commonly used to study of fish fry sampling of fish eggs and early fry stages ecology in reservoirs and lakes. My colleagues and I have evaluated trawl efficiency and sampling of earliest fry stages standardized net sizes for sampling. Bongo nets with a 3 x 3 m frame size, 6 mm mesh size sampling of 0+ fish in front and 4 mm mesh in the rear became a standard net for fry sampling in reservoirs and lakes. This net can sample at night without any apparent fish escape reaction. Thanks to the size of the net, it Advantages of trawls – frame trawls: is easy to manipulate and does not require an extremely powerful draught vessel. It is also possible to sample in possible to sample in a wide range of depths various depths of the water column. Bongo nets are useful for collecting quantitative and qualitative characteristics can sample a large water volume of fish fry communities in the open water of reservoirs and lakes. With this type of net I have conducted ecological minimal damage to fish studies of fish fry distribution and behavior, all results are published in high impact journals. Also, it revealed mobile and easy to control some phenomena of certain fish species ecology. I offer consultations about the usefulness of fish fry sampling obtain information about the precise fish fry composi- techniques. I also offer fish fry surveys in all habitats in reservoirs and lakes. tion and abundance in the sampled time and area Contact: +420 733 373 139, [email protected] easy to compute results into the units of sampled http://www.fishecu.cz/staff-members/juza water volume Relevant fish fry sampling gear publications:

General principles for successful sampling: t Jůza, T., Kubečka, J. 2007. The efficiency of three fry trawls bathypelagic layer of a canyon-shaped reservoir. Fisheries sufficiently strong and fast vessel to the size and for sampling the freshwater fry community. Fisheries Re- Research 123-124: 21-25. design of the net used search 85(3), 285-290. t Jůza, T., Rakowitz, G., Draštík, V., Blabolil, P., Herzig, A., the speed must be close to 1 m/s (Čech et al. 2005) t Jůza, T., Čech, M., Kubečka, J., Vašek, M., Peterka, J., Kratochvíl, M., Muška, M., Říha, M., Sajdlová, Z., Kubečka, J. sampled trajectory is measured with a GPS tracker Matěna, J. 2010. The influence of the trawl mouth opening 2013. Avoidance reactions of fish in the trawl mouth opening in a sampled volume of water is measured most pre- size and net colour on catch efficiency during sampling of shallow and turbid lake at night. Fisheries Research 147: 154-160. early fish stages. Fisheries Research 105, 125-133. cisely with flowmeter t Jůza, T., Vašek, M., Kratochvíl, M., Blabolil, P., Čech, M., sufficient size – design of the net t Jůza, T., Čech, M., Kubečka, J., Vašek, M., Peterka, J., Draštík, V., Frouzová, J., Muška, M., Peterka, J., Prchal- Kratochvíl, M., Frouzová, J., Matěna, J. 2012. The influ- ová, M., Říha, M., Tušer, M., Kubečka, J. 2014. Chaos and correct mesh size ence of the trawl mouth opening size and net colour on stability of age-0 fish assemblages in a temperate deep use draught ropes with a suitable length catch efficiency during sampling of early stages of perch reservoir: unpredictable success and stable habitat use. trawl trajectory must not copy the vessel trajectory (Perca fluviatilis) and pikeperch (Sander lucioperca) in the Hydrobiologia 724: 217-234. the net has to be placed correctly in the water trawl has to be balanced correctly suitably chosen accessories for the net and frame – Position of the trawl net in the water column floats, leads, wheels or skids

in water column – frame with leads near bottom / on the bottom under water metal collecting and float, length of the rope leading – frame with skids / wheels to prevent – frame with the float container and to cord drives the trawl depth from getting stuck flowmeter 61 Funnel Trawl trajectory behind the vessel possible to sew the funnel inside the net:

funnel does not prevent the catch from going to the rear part of the net funnel prevents from the catch escaping - when the trawl slows down - when the trawl is pulled to the vessel Ichtyoplankton net – trawl (or moves slowly) - when the net does not move ichtyoplankton nets are included in trawl nets Net design it is possible to sample the whole water polyester net with 2 mm mesh size colors: black, white column net length 8 or 10 m Outlet end possible net ending: Usage: NET HAS A PROTECTIVE HEM sampling of large invertebrates in the open water MADE FROM POLYAMIDE OR PVC metal collecting container sampling of fish eggs, larvae and early fish stages - option 1: frame is freely threaded through the hem - all catch is flushed to the collecting container when sampling of the earliest fish stages - option 2: frame is attached to the inner metal rings the net is pulled out of the water - detaching is bayonet based mechanism Frame design of the hem with the cord - option 3: frame is firmly sewn into the hem cod end from dense mesh size CIRCULAR FRAME WITH 90 cm DIAMETER - after the net is pulled out of the water, untie the net - circular frame is made from steel wire and wash out the catch into prepared container - frame has 3 binding rings - circle diameter 90 cm - wire diameter 8 mm - powder coated

DETACHABLE FRAME MADE FROM SQUARE TUBES - frame size 2 x 2 m - frame is detachable in corners NET ENDING - frame wide 3 m and more is - option 1: funnel and detachable metal container divided into more parts for collecting - option 2: funnel and cod end - frame has 4 – 6 binding rings collecting container cod end - powder coated - option 3: cod end cod end – fold and tie up MATERIAL MESH SIZE (in mm) FRAME DIAMETER (in m) LENGTH (in m) Tyl 2 x 2 2 6 Tyl 2 x 2 square-shaped 2 x 2 6

62 Ichtyoplankton net - trawl - frame 2 x 2 m, detachable construction - tyl net – 4 m length, funnel sewn in the net - metal collecting container

Ichtyoplankton net - trawl - frame, ring diameter 2 m, wire thickness 12 mm - tyl net – 6 m length, funnel sewn in the net - metal collecting container

63 Fry trawls – bongo nets

bongo nets belong to the category of trawl nets can sample at all depths

Usage: sampling of 0+ fish and adults Net design NET ENDING polyamide net - funnel and cod end, length 1.5 m, mesh size 4 mm Frame design thread thickness 201/4 – 6 mesh size 4 and 6 mm DETACHABLE FRAME Funnel white color MADE FROM SQUARE TUBES net length depends on frame size – 9.5, 10.5, 16.5 m funnel prevents the catch from escaping - when the trawl slows down length of the NET HEM IS MADE FROM PVC - when the trawl is pulled to the vessel cod end - option 1: frame is freely threaded through the hem (or moves slowly) - option 2: frame is attached to the inner metal rings - when net does not move of the hem with the cord

FRAME IS THREADED THROUGH THE HEM length

length of suspension ropes height frame threaded through the frame attached to the hem hem by a cord width

- sizes: 3 x 1.5 m, 3 x 3 m, 6 x 3 m - can detach frame in corners - frame wide 3 m and more is divided into more parts - frame has 4 – 6 binding rings - powder coated frame threaded through the hem connection of the cod end view of the funnel from the and the trawl body inside of the net Time-tested standard sizes of frame trawls made for research institutes: MESH SIZE OF THE BODY / WIDTH HEIGHT LENGTH OF SUSPEN- LENGTH OF THE LENGTH OF THE COD END MESH SIZE OF THE COD END(in m) (in m) (in m) SION ROPES (in m) TRAWL BODY (in m) FUNNEL(in m) (in m) 6 / 4 3 1.5 1.85 9.5 0.5 1.5 6 / 4 3 3 2.9 10.5 0.5 1.5 6 / 4 6 3 4.55 16.5 0.5 1.5

64 Frame trawl has skids or wheels according to the character of the bottom

demonstration of benthic trawl sampling

65 Circular dragnet – designed for circular storage pools Fishing effectively, quickly and carefully

The circular dragnet is a great tool for farming rainbow trout and other salmonid species in round storage tanks.

Usage: comfortable fishing from round storage tanks by one or two persons

Advantages: ease of use by one or two persons high fishing efficiency (90 %) careful fish handling possible to change the net volume according to the amount of fish possible to feed fish in the net according to your needs possible to use a fish pump for transport Correctly chosen net size is the key to successful fishing !!!

Composition: polyamide knotless net mesh size 10, 15, 20, 25 mm thread thickness 0.5 – 1.4 mm (210/18 – 210/27) the strip of the net is reinforced with rope steel rings are attached to sides and lower line colored drawstring is threaded through rings

Developed for your fish net size: farm by the Pokorný-Sítě net height = storage height (h) + radius (r) company. net length = storage perimeter (p) + 1 m

66 Instructions for using a circular dragnet

fold the net into a vat or handcart (wheelbarrow) after casting the net, both ends should be touching fold lower line with rings and colored drawstring on one side tie up both ends so upper line does not slip from the tank edge fold upper line on the opposite side after casting the net, lure fish into central part of the tank by food tie upper line and the end of the colored drawstring to a fixed place on the round when fish start feeding, quickly pull the drawstring, which is threaded through tank rings attached to lead line and to the net sides cast the net – spread out around the tank perimeter drawstring is fixed to the middle ring pay attention that no fish are caught between the net and sides of the tank pull both drawstring ends evenly so the net is evenly hauled cast rings with colored drawstring into water, lower them to the bottom along the haul ends when all rings are lifted above the edge of the tank sides of the tank 90 % of fish stock is usually caught pay attention to ensure that the threaded drawstring does not tangle it is possible to transport fish with fish pump, hand net or dip net attach upper line to the tank edge/ put it over the tank edge

67 Round drop net increase fishing efficiency by adding 0.5 m of rope Round drop nets are used for catching and keeping small amounts of fish (20 – 50 kg).

Usage: fishing from channels, fish storage ponds and tanks easy and convenient fishing for trout and other salmonids easy fishing for fish accustomed to artificial food suitable for individual use – catching and storing of fish caught daily

Advantages: easy manipulation by one person 90 % fishing efficiency used for careful handling of fish caught easy to transport – possible to carry net to location

Composition: steel wire frame sinking the drop net lifting the net quickly fixing frame above the water 3 suspension points to the bottom – feeding to the surface level and fish removing 3 slings from rope 1 – 1.5 deep nets are sewn or attached to the frame frames with a diameter greater than 1.5 m Instructions for round drop net use: can be dismantled round drop net with a 0.9 m diameter can be lifted by hand moderately feed fish to lure them to the fishing spot net remains attached to the frame even after round drop net with a 1.5, 2, or 2.5 m diameter require lift after fish gather above the drop net dismantling a lever arm to lift lift metal frame just slightly above the water level tighten the rope loop directly to wooden pole do not lift caught fish with drop net adjust the loop according to nature of the fishing spot pull drop net to the shore and remove fish with hand sink the drop net to the bottom of the water– under net or dip net to prepared vat the fished shoal

Round drop net available sizes MESH SIZE (in mm) NET – FRAME DIAMETER (in m) Developed for your fish 10 0.9, 1.5, 2, 2.5 farm by the Pokorný-Sítě 15 0.9, 1.5, 2, 2.5 company. 20 0.9, 1.5, 2, 2.5 Cast net

Usage: fishing for small amounts of fish from ponds or fish storage ponds sampling small amounts of fish from commercial ponds suitable especially for carp fishing

Composition: polyamide net (see table for mesh sizes available) thread thickness 0.5 – 1.4 mm (210/4 – 210/27) the strip of netting is sewn into a shallow cone-shaped net cast net is sewn on the central metal ring perimeter has sewn lead line drawstrings are threaded through the ring drawstrings are attached to lead line around the net perimeter drawstrings are attached to main drawstring

Instructions for use (for right-handers): let the cast net sink to the bottom – fish must be put the sling from main drawstring on your right hand covered with the net fold main drawstring in your right hand give net a tug to close– lead line is constricted to ensure that drawstrings are not crossed central ring grasp both rings - net and drawstring ring - into your this move catches fish in the net – lead line goes right hand with folded main drawstring under the fish on the bottom add lead line from the edge of the cast net into your by pulling the main drawstring, the net containing fish right hand is pulled to the shore with your left hand, grasp perimeter lead line with net is emptied by grasping the metal ring and releas- your “arms “mildly spread” ing drawstrings stretch out – twist body in right hand direction and throw cast net by body rotation on to desired place The instructions for use for left-handers is the mirror net must fall to the spot where targeted fish occur!!! image of the description above

Cast nets are made in time-tested sizes MESH SIZE (in mm) NET DIAMETER (in m) what happens below water surface 6, 10, 15, 20, 25, 30 1, 1.5, 2, 2.5 after the net was casted Fish traps maintain caught fish in good health

70 Fish traps Traps use for scientific sampling and fisheries prof. RNDr. Jan Kubečka, CSc. fish traps belong to passive My scientific career is associated with the Institute of hydrobiology of the Academy of Sciences CR and focuses on research into the ecological role of fish community in reservoirs and lakes. fishing gear I participated in methodological development of many fishing techniques and gears, which are useful in large water ecosystems – beach seine nets, gillnets, trawls, purse seine nets, fish fish are caught by their actively traps, scientific echosounders, usage of electrofishing etc. swimming into the body of the fish Technical improvements were tested many times in the Czech Republic as well as abroad Thanks to the 30-year development of sampling methodologies, it is nowadays possible to trap, which results in their capture achieve a quite accurate quantitative picture of composition and distribution of fish communi- ties, when robust methods such as multimesh gillnets, trawls and beach seine nets are used correctly. The unfortunate and sad result of this sampling is its effect on fish life and the fre- Principles of fish trap quent mortality of captured fish. This is one of the reasons why a substantial part of my scien- fish trap – the wings of a fish trap makes a tific career is dedicated to the development of indirect fish study, particularly the use of scientific echosounders. barrier in the lentic or lotic water Fish traps are quite a gentle way to sample fish fish runs into the wings and swims into the body First, I worked with fish traps during my diploma thesis at the Faculty of Science, Charles University in Prague, which dealt of the fish trap with fish fry communities in the Klíčava Reservoir. Klíčava traps were specially developed for this reservoir and were ef- nozzles are part of the trap – funnel-shape part fective especially for sampling perch (Kubečka & Švátora 1993). When I started to work at the Institute of Hydrobiology of at the entrance part of the trap, the Academy of Sciences CR, I developed larger fish traps together with a net builder named František Hamr. These fish nozzles – funnel-shape disable fish from traps were then used for mark-recapture studies and biomanipulation purposes. They were named after the main locality escaping the fish trap of usage – medium trap. They have been used in a nearly unchanged design for almost 30 years. An ambitious project was completed at the turn of the 20th century Usage The importance of tributary zone for fish community of the reservoir was studied in cooperation with Pokorný – Sítě sampling fish and commercial fishing in lentic company. We developed two specially designed giant traps which were able to examine whole fish migration between and lotic waters the Římov Reservoir and its main tributary, the Malše River (Hladík et al. 2002). These two traps were installed during shape and size is adjusted to the fishing migration period for four years and their use enriched our knowledge about migration of fish between reservoir and river location (Hladík & Kubečka 2003, 2004, Hladík et al. 2008, Říha et al. 2013). shape and size is adjusted to the targeted fish Klíčava traps, standard Římov traps and modified Římov traps with heart have recently been used in sampling of fish com- species munities in Římov Reservoir and post-mining lake Milada (Říha & Kočvara, personal communication; Peterka et al. 2012). different fish trap are variously selective when Contact: [email protected] fishing in the same locality References:

Our standard range of fish traps includes t
Hladík, M., Kubečka, J., Pokorný P., Čech M., Draštík, V., t
Kubečka, J. and Švátora, M.,1993: Abundance estimates of several tested types with a broad scale of Kratochvíl, M., Peterka, J., Prchalová, M., Vašek, M., 2002: perch fry {Perca fluviatilis} complicated by grouped behaviour. Giant traps for fishing in the inflow zone of the Římov Reservoir. Ecology of Freshwater fish, 2: 84-90. chambers ranging from 0.1 to 100 m3. In: Spurný, P. (ed.) The 5th Czech conference of Ichthyology, t
Peterka, J., Adámek, Z., Blabolil, P., Bouše, E., Čech, M., Draštík, Proceedings of the international conference: 126-131 V., Frouzová, J., Havel, L., Hohausová, E., Jankovský, M., Ja- t
Hladík, M., Kubečka, J., 2003: Fish migration between the rolím, O., Jurajda, P., Jůza, T., Kočvara, L., Kratochvíl, M., Kubeč- reservoir and its main tributary. Hydrobiologia 504: 251-266. ka, J., Muška, M., Prchalová, M., Richta, J., Říha, M., Sajdlová, t
Hladík, M., Kubečka, J., 2004. The effect of the water level Z., Soukalová, K., Tušer, M., Uhlířová, A., Uhlíř, F., Vašek, M., fluctuation on tributary spawning migration of reservoir fish. Vejřík, L., Veselý, L., Vlasák, P., 2012: Ryby nádrže Milada. str. Ecohydrology and Hydrobiology, 4: 449-457. 92-111 In: Šutera V. a kolektiv (eds.), 2012. Příroda nádrže Milada - území po zatopení lomu Chabařovice. Lesnická práce, s. r. o., t
Hladík, M., Kubecka, J., Mrkvička, T., Čech, T., Draštík, V., Kostelec n. Č.L., 207 str. ISBN 978-80-7458-024-6. Frouzová, J., Hohausová, E., Matěna, J., Matěnová, V., Kra- tochvíl, M., Peterka, J., Prchalová, M., Vašek, M., 2008: The t
Říha, M., Hladík, M., Mrkvička, T., Prchalová, M., Čech, M., effect of the construction of a reservoir on the fish assemblage Draštík, V., Frouzová, J., Jůza, T., Kratochvíl, M., Peterka, in an inflow river. Czech J. Anim. Sci., 53, 12: 537-547. J., Vašek M., Kubečka J., 2013: Post-spawning dispersal of tributary spawning fish species to a reservoir system. Folia t
Kubecka, J., 1992: Fluctuations in fyke-net catches during the Zoologica 62 (1): 1–13. spawning period of the Eurasian perch {Perca fluviatilis} in the Římov Reservoir, Czechoslovakia. Fisheries Research, 15: 157-167

71 Instructions for use float on lifiting cord Fish trap preparation - wings are tied to the main body with wing stretching cord for transport nozzle stretching - fix wings in the front of the trap entrance in a cord - loosing the V-shape (angle 30 – 40°) wing stretching cord hanging cord will lead to system - use wing stretching cord (part of the trap) to trap emptying fix the wings - stretching cord starts and ends at the edge of the right wing - nozzle is stretched using inner stretching cord - trap has 3 suspension points and lifting cord with the float for installation body - trap has to be in a horizontal position after nozzle lifting it in the air - install the trap in water in a horizontal position wings

Installation of the fish trap - wings must be at an angle of 30 - 40° Klicava trap - the trap is installed in set position – ready to Klicava trap was originally developed for perch sampling in the Klicava and catch fish Záskalská Reservoirs. Traps were successfully used for biomanipulation in - the trap is casted into the water using the Římov Reservoir (Kubečka, 1992). lifting cord with the float - the trap is installed on the bottom - install the trap parallel to the shore when the Usage: slope is steep Klicava trap – successful sampling of small benthic fish species - it is suitable to use this trap type when the slope is no steeper than 50° useful for fish species dwelling in macrophytes – perch, European - cast the trap vertically to avoid getting stuck eel, burbot, gudgeon, tench, pike or overturning the trap the smallest standard and commonly used type of fish trap

Advantages: Lifting the trap from the water and emptying small size, weight and price - Klicava trap can be emptied every 3 to 7 days easy to store - trap is lifted above the water level using the self-supporting construction lifting cord with the float ready to sample immediately – no need to adjust wings after installation - lay the trap on the boat and untie the nozzle installation into any arbitrary depth and also into locations with limited space stretching cord installation on the steep slope of the bank - untie the wing stretching cord for better installation into structured environment (e.g. submerged tree stumps, etc.) comfort (not necessary) easy manipulation by one person – installation and removal of catch - place the trap into vertical position bottom-up catch remains in good condition for a long time after capture - use the nozzle oriented right side out to empty the depending on water temperature, remove the catch every 3 to 7 days fish caught into the prepared vat filled with water - it is suitable to wash the trap from algae Disadvantages: before recasting in the water high selectivity - wash by quick vertical moves of the trap in the water column does not catch species such as bleak, roach, bream

72

5 mm ø 6 mm

mm mm mm

mm mm

Sizes: body – 40 x 40 x 80 cm wing length - 80, 120 cm mesh sizes 6, 10, 15 mm

Design: frame made from metal wire wire diameter 6 mm wings are attached via hinges powder coated – green polyamide knotless net with the diamond-shaped mesh mesh sizes 6, 10, 15 mm thread thickness – 210/6 – 210/18 net is stretched and sewn to the frame klicava trap – lifting, klicava trap - removing caught perch is in good trap has one nozzle installation of set trap fish through nozzle condition even after several days nozzle has a cord attached for stretching and emptying the trap 3 suspension point designed for casting the net horizontally 10 m lifting cord with the float Keep in mind the following Klicava trap is made in time-tested design and sizes ethical standard - a fish trap MESH SIZE WIDTH HEIGHT BODY LENGTH WING LENGTH lost is still fishing (in mm) (in cm) (in cm) (in cm) (in cm) use our gillnet finder for finding 6, 10, 15 40 40 80 80 and lifting a lost trap. 6, 10, 15 40 40 80 120

73 float

float above depth anchors trap body of 5 m

anchors

wings nozzles

anchors Rimov trap

Used on many occasions in large water bodies in the Czech Republic as the main tool for biomanipulation with perch (Kubečka 1992, Seďa & Kubečka, 1997) Sizes: polyamide knotless net with dia- steel ring diameter 90 cm mond-shaped mesh Usage: body length – 4 or 6 m mesh sizes - 15, 20 mm number of nozzles – 2 thread thickness 210/18

Rimov trap – successful in catching benthic species wing height – 90 – 120 cm wing length: 5 – 10 m useful for fish species dwelling in macrophytes wing length – 10 m wings have floats and weights perch, European eel, burbot, gudgeon, tench, pike, pikeperch, catfish etc. lifting cord with the float Design: stretching cords for attaching anchors designed for large water bodies with gentle slope of the bank (up to 20°) rings made from steel wire and rods many shape and size modifications available wire diameter 8 mm powder coated 3 chamber volumes: 0.1 – 100 m body – cylindrical net with two nozzles

Advantages: easy to store Rimov trap is made in standard design and its modifications. possible to install at depths (up to 20 m) MESH SIZE DIAMETER (in m) / NUMBER WING NUMBER catch remains in good condition for long time (in mm) NUMBER OF FRAMES OF NOZZLES LENGTH (in m) OF WINGS depending on water temperature, remove the catch every 3 to 7 days 0.4 x 0.4 m / 5 15, 20 2 5 - 10 m 2 Disadvantages: – Square-shaped underestimation of catch of certain fish species (Kubečka, 1992) 15, 20 0.4 m / 5 – Ring-shaped 2 5 - 10 m 2 15, 20 0.6 m / 5 - Ring-shaped 2 5 - 10 m 2 Underestimation was solved by adding another nozzle 15, 20 0.7 m / 5 – Ring-shaped 2 5 - 10 m 2 to the Rimov trap. 15, 20 0.9 m / 5 – Ring-shaped 2 10 m 2

74 Instructions for use:

Trap installation

anchor release the float

final stretch (30°) anchor + stretch (30°) setting (40°) casting trap body

anchor

Rimov trap with heart Trap lifting It is a modification of the Rimov trap. A larger nozzle was added in front of the heart, which forms the first part of the trap body. anchor Advantages: the modification results in non-selective fish sampling cyprinid fishes are also caught in this type of fish trap the data obtained with this gear can be considered to be a representative sample anchor (kubečka 2007)

Rimov trap with heart is made in a time-tested design and size first frame fifth frame MESH SIZE DIAMETER (in m) / NUMBER WING NUMBER (in mm) NUMBER OF FRAMES OF NOZZLES LENGTH (in m) OF WINGS anchor 1.2 m / 3 ks 0.9 m / 5 pieces 15, 20 3 10 – 20 m 2 1.2 m / 3 pieces 0.9 m / 5 pieces General principles cast the trap from a row boat powered by oars stretch the trap with poles or 3 (metal, concrete or stone) anchors it is possible to install the trap to maximal depth of 20 m optimal depth is 10 m or less cast the trap parallel to the shore Rimov trap is installed on unstructured bottom with gentle slope up to 20° successful fishing – set the wing angle at 30-35° to the trap center line trap has to be stretched precisely with three fixed points trap lifting: - first lift the back anchor - lift the trap using the first frame with the float

75 Only a correctly set fish trap catches fish! - stretch the body on the board and ensure that the frames are not twisted Easier to empty traps with two persons. - attach the anchor to the rear stretching cord and lay it into the boat Pay attention to the trap wings not turning over or deform during emptying the - throw the float and lifting cord of the front frame in the water trap. - stretch the trap body and place it in the water accordingly to the position of If anchors move during fish removal, it is necessary to lift the whole trap and both wings and their anchors set it again. - the body and wings of the trap must not be twisted or deformed in any way - the rear anchor attached to the stretching cord of the trap body is placed in the water last Folding trap to the boat - check if the trap is stretched even after throwing the anchor in the water - carefully tie the end of the trap before folding - attach the cords with floats to the trap that is placed at depth – the floats have - fold the trap on the foredeck to form the letter “Y” if installed correctly - start with last frame of the trap body and end with the front frame with wings - after final stretching of the main body, the angle decreases from the original 40° - fold wings on the front frame separately to the intended 30° - 35° - fold stretching cord for wings last - floats are oriented towards the stern and anchors towards the foredeck

Trap installation using anchors - find a suitable and sufficiently large location - attach an anchor of at least 15 kg to both stretching cords of the wings - throw the nearshore anchor into the water first - estimate a 70° angle to the shore and row in this direction – stretch the stretching cord and cast the wing into water - after the wing has been stretched, cast a sufficiently long cord with the float attached to the front frame - cast the trap body in desired direction - leave the second anchor on the boat and turn the boat in the direction in which the second wing will be casted - stretch the second wing and pay attention to setting the wing angle at 30-35° to the trap center line - place the anchor in the water - the second wing has to be mildly stretched - row to the trap body and lift it using the lifting cord with the float

76 Trap lifting and removal of the catch Klicava trap can be emptied every 3 to 7 days - possible to lift the trap placed at a maximum depth of 5m by using the lifting cord with the float attached to the first frame of the trap - if deeper, start by lifting the rear anchor attached to stretching cord, followed by lifting the first frame of the trap - lift above the water level on the bow and add other frames - when lifting the trap, shake the catch to the rear of the trap - once all frames are on the boat and fish are in the rear of the trap, untie the trap outlet and empty the catch into the prepared vat - tie the trap and set again - we recommend cleaning the trap by dragging through the water to remove algae and alluvium - Only a clean trap is effective! A dirty trap is visible and does not catch fish!

Keep in mind the following ethical standard - a fish trap lost is still fishing use our gillnet finder for finding and lifting a lost trap.

77 Rimov tributary trap Trap was supported with a metal self-supporting frame, which was used to: support and anchor the frame in the current Tributary trap was used for monitoring fish migration between the Římov support the frame for fish removal Reservoir and its main tributary – Malše River. support the frame for cleaning of algae and for trap reparation Two fish traps were installed close to each other in the tributary of the reservoir. Fish caught were removed twice a week or more frequently into a floating cage and the first was oriented towards the dam part of the Římov Reservoir then scientifically processed. the second was oriented towards the tributary part

Sizes: entrance 3 x 3 m trap length 13.5 m entrance part – 1 piece number of nozzles – 2 wing height – 3 m wing length – 25 m

Design: Net: Frame: polyamide knotless net with dia- entrance – metal square mond-shaped mesh tube 30 x 30 mm mesh size 15 mm pot – wire rings thread thickness 210/18 wire diameter 12 mm wing length – 25 m colored surface wing has floats and lead line attached

78 nozzles

entering gate

Tributary fish traps capture all kinds of migrating fish (Hladík et al. 2002).

Mark and recapture of fish using Rimov tributary traps belongs to the largest marking experiments in history of the Czech ichthyologic.

more than 50 thousand migrating fish were captured and marked whole season monitoring showed that most of fish migrate into the river for spawn- ing and return into the reservoir relatively soon after spawning populations of fish such as asp, white bream, chub migrate into the tributary for spawning species such as roach, bream and perch migrate only from adjacent part of the reservoir the smallest migrating distance was observed for pike and perch on average, one fifth of the whole reservoir population migrates into the tributary

Rimov tributary traps can be used for biomanipulation with purposes.

79 Gillnets

Gillnets are suitable for scientific research

80 RNDr. Marie Prchalová, Ph.D. I work at the Institute of Hydrobiology (Biology References: Centre AS CR, v.v.i., Fish Ecology Unit). My re- t
Prchalová, M., Kubečka, J., Říha, M., Čech, M., Jůza, T., Ketelaars, H.A.M., Kratochvíl, M., search focuses on fish ecology in reservoirs, es- Mrkvička, T., Peterka, J., Vašek, M., Wagenvoort, A.J., 2013. Eel attacks - A new tool pecially fish spatial distribution. In addition, I also for assessing European eel (Anguilla anguilla) abundance and distribution patterns with work on gillnet sampling methodology of fish com- gillnet sampling. Limnologica 43, 194-202. munities. I am an active contributor to the devel- t
Prchalová, M., Peterka, J., Čech, M., Kubečka, J., 2013. A simple proof of gillnet opment of standardized sampling and evaluation saturation. Boreal Environment Research 18, 303-308. techniques of fish communities for the European t
Tušer, M., Prchalová, M., Mrkvička, T., Frouzová, J., Čech, M., Peterka, J., Jůza, T., Vašek, M., Kratochvíl, M., Draštík, V., Kubečka, J., 2013. A simple method to correct Water Framework Directive and I assist in updating the results of acoustic surveys for fish hidden in the dead zone. Journal of Applied the European Standard EN 14757 (“Water quality Ichthyology 29, 358-363. – sampling of fish with multimesh gillnets”). In the t
Prchalová, M., Neal, J. W., Munoz-Hincapié M., Jůza, T., Říha, M., Kubečka, J., 2012. past, I have participated in the Spanish Ministry of Comparison of gillnets versus fixed-frame trawl for sampling threadfin shad in tropical Environment's project on the calibration of sam- reservoirs. Transactions of the American Fisheries Society 141, 1151-1160. pling methods in Spanish reservoirs. I also contrib- t
Prchalová, M., Mrkvička, T., Peterka, J., Čech, M., Berec, L., Kubečka, J., 2011. A model uted to projects of tropical fish ecology in reservoirs of Thailand, the Philippines, of gillnet catch in relation to the catchable biomass, saturation and soak time. Fisheries Sri Lanka and Puerto Rico, and was involved in fish community research in Dutch Research 107, 201-209. reservoirs, which was financed by the Dutch drinking water company. t
Prchalová, M., Mrkvička, T., Kubečka, J., Peterka, J., Čech, M., Muška, M., Kratochvíl, In my work I analyze gillnet sampling methodology of fish communities I and am M., Vašek, M., 2010. Fish activity as determined by gillnet catch: A comparison of two an internationally respected and cited author. I am also involved in reviewing scien- reservoirs of different turbidity. Fisheries Research 102, 291-296. tific manuscripts prior to their acceptance to journals. I was the principal researcher t
Prchalová, M., Kubečka, J., Říha, M., Mrkvička, T., Vašek, M., Jůza, T., Kratochvíl, M., of two projects which dealt with gillnet methodology. Together with my colleagues, Peterka, J., Draštík, V., Křížek, J., 2009. Size selectivity of standardized multimesh gillnets in sampling coarse European species. Fisheries Research 96, 51-57. I have published many scientific articles on gillnet sampling of fish communities. t
Vašek, M., Kubečka, J., Čech, M., Draštík, V., Matěna, J., Mrkvička, T., Peterka, J., For example, we examined the underestimation of small fish and overestimation Prchalová, M., 2009. Diel variation in gillnet catches and vertical distribution of pelagic of large fish in gillnet catches (Prchalová et al., 2008 and 2009). Gillnet catches fishes in a stratified European reservoir. Fisheries Research 96, 64-69. were also used to describe fish activity in detail (Vašek et al. 2009, Prchalová et al. t
Prchalová, M., Kubečka, J., Říha, M., Litvín, R., Čech, M., Frouzová, J., Hladík, M., 2010). A model of gillnet sampling was developed and we suggested a new way to Hohausová, E., Peterka, J., Vašek, M., 2008. Overestimation of percid fishes in gillnet express gillnet catches. This model avoids the influence of changes in fish activity, sampling. Fisheries Research 91/1, 79-87. fish escapement from gillnets during exposure and saturation of gillnets (Prchalová et al. 2011 and 2013). In Prchalová et al. 2012, the advantages and disadvantages of catching small tropical fish Dorosoma petenense into gillnets and trawls are discussed. Gillnets were also used in research estimating the abundance of fish in the blind zone of a hydroacustic survey (Tušer et al. 2013). Based on sections of the entangled gillnet where the eel attacked fish caught in gillnets, we described the estimation of the European eel (Prchalová et al. 2013). Recently my work entails appropriate gillnet sampling design, with the calibration of gillnet catches accord- ing to known fish communities and with differences in gender-dependent gillnet catchability of several fish species. All my research is based on using gillnets made by the Pokorný-sítě company. We collaborate on development of the new gillnet types and in innovation of the sampling design. [email protected] http://www.fishecu.cz/staff-members/prchalova/

81 Gillnets The exceptional status of gillnet data in Europe In our contemporary and globalized world, the crucial issue is the use of a standardized What was enmeshed in gillnet is likely to become a filet. method which enables data comparison among countries. The European Committee for Standardization (CEN), consisting of experts from 33 European countries, is the most important such organization in the European sphere. The norms produced by CEN are gillnets are used to catch fishes in both freshwater accepted by individual member countries as national norms. The most important docu- and marine environments ment in the field of fish sampling is the norm CEN14962 “Water quality — Guidance on the scope and selection of fish sampling methods”, which also exist in Czech as ČSN EN gillnets belong to the group of passive fishing gear 14962 (757710) Water quality — Guidance on the scope and selection of fish sampling methods. The norm describes the process to choose the appropriate evaluation method the catch success is fully dependent on fish activity for fish communities in rivers, lakes and brackish waters. Each method is also briefly de- gillnets create a wall of netting, in which the fish is enmeshed scribed and the recommendation for each ecosystem is included in the norm. For exam- ple, with respect to the goal of monitoring, sampling by beach seining is recommended The advantages of gillnets: for use in inshore areas of lotic fresh waters, while trawling, drifting gillnets or traps are the recommended sampling methods for offshore areas. In lentic waters beach seining the possibility of fishing in all available depths is recommended for sampling inshore areas, while offshore areas should be sampled the possibility of fishing on any slope of the bottom with traps, and in the case of large, deep water bodies purse seining and trawling can the possibility of fishing in almost all habitats – in lake / reservoir be used. Nets have a broad range of applications with which no other sampling method the spectrum of catchable fish is very broad (unlimited) can compare. fish of all sizes can be caught in gillnets due to the geometric series of mesh sizes, fish across the length-frequency distribution are able to be caught samples caught in gillnets serve as the basis for determining the length-frequency and age–frequency distribution of a population our gillnets fulfil the requirements of Water Framework Directive

These advantages make gillnets one of most used nets for the fish community research.

The importance of gillnets as a sampling tool is emphasized by the European Standard Document (EN 14 757 Water quality – Sampling of fish with multimesh gillnets, revision 2014).

The European Norm was approved as the Czech National Norm ČSN EN 14757 Water quality – Sampling of fish with multimesh gillnets (revision 2015).

The Norm describes the methodology of fish stock assessment in terms of species occurrence, size composition, quantitative relative abundance and biomass expressed to unit of effort (Catch Per Unit of Effort, CPUE) of a fish community in lentic waters of the temperate region. This Document further contains a design of gillnets together with the summary of mesh sizes and their thread diameters.

82 Gillnets as the main sampling method Innovations of scientists Currently the most important legislative document in the field of EU water policy is the from the Institute of Hydrobiology Water Framework Directive (2000/60/ES). This document instructs member countries to develop a national methodology to evaluate the ecological state of natural water bodies BC AS CR, v.v.i. in České Budějovice and the ecological potential of strongly modified and man-made water bodies. In the Czech Republic, the methodology for evaluating the biological components of fish in res- extend the standard gillnet series (12 mesh sizes) by an additional ervoirs and artificial lakes was based on the data obtained from gillnet samples (Borovec et al. 2014). The next step is the process of inter-calibration where member countries 4 mesh sizes are grouped according to their geographic region to compare and discuss the various the additional mesh sizes are 70, 90, 110 and 135 mm methodologies. The Czech Republic belongs to the Central and Baltic region (C/B GIG). Experts from other countries in the region use gillnet sampling to obtain information large meshes are suitable for large specimens of carp, pikeperch, about fish communities. Concurrently, the gillnet sampling is standardized by European bream, rudd, tench, pike, catfish etc. (above 35 cm of length) Norm CEN 14757 Water quality - Sampling of fish with multi-mesh gillnets (Czech version ČSN EN 14757). mesh sizes follow the geometric series using a factor of 1.25 Cross-European attempts to unify the evaluation of fish communities within the WISER Design: project (www.wiser.eu) resulted in the formation of the European database of fish catches large mesh gillnets are installed as a separate gillnet (Causeé et al. 2011). The data characterizing lakes exclusively include gillnet catches, total length of the buoyancy line is 40 m which in the case of the Czech Republic were made by the Pokorný – Sítě company. The total length of the lead line is 48 m first results were based on benthic gillnet catches solely from natural lakes (e.g. Argillier the length of each mesh panel is 10 m in the gillnet et al. 2013, Brucet et al. 2013). Further research will also focus on artificial lakes and on the height, the type and design is in accordance to the basic types of gillnets the sampling of pelagic fish communities. benthic gillnets has height of 1.5 m pelagic gillnets has height of 3 m, 4.5 m or 6 m

Innovations in the deployment of gillnets: sampling in order to obtain many independent samples three or four gillnets are joined together to create a gillnet set joining gillnets into sets with a long rope (usually 30 m) is more efficient than installing single gillnets

Description of innovations: Descriptions of the innovations are included in the book Methodology of monitoring fish communities in lakes and reservoirs (publisher Institute of Hydrobiology, BC AS CR, v.v.i., collective authorship J. Kubečka, J. Frouzová, T. Jůza, M. Kratochvíl, M. Prch- alová, M. Říha, 64 pp., in Czech), which also includes descriptions of trawling, beach seining, electrofishing and hydroacoustic methodology. References: t Argillier C., Caussé S., Gevrey M., Pédron S., De Bortoli J., Brucet S., Emmrich M., Jeppesen E., Lauridsen T., Mehner T., Olin M., Rask M., Volta P., Winfield I. J., Kelly F., Krause T., Palm A., Holmgren K., 2013. Development of a fish-based index to assess the eutrophication status of European lakes. Hydrobiologia. 704: 193-211. t Brucet S., Pédron S., Mehner T., Lauridsen T. L., Argillier C., Winfield I. J., Volta P., Emmrich M., Hesthagen T., Holmgren K., Benejam L., Kelly F., Krause T., Palm A., Rask M., Jeppesen E. 2013. Fish diversity in European lakes: geographical factors dominate over anthropogenic pressures. Freshwater Biology 58: 1779-1793. t Causseé S., Gevrey M., Pédron S., Brucet S., Holmgren K., Emmrich M., De Bortoli J., Argillier C., 2011. Deliverable 3.4-4: fish indicators for ecological status assessment of lakes affected by eutrophication and hydromorphological pressures. Irstea, Aix en Provence, 46 str. t Methodology for the assessment of the ecological potential of heavily modified and artificial water bodies– lake category (Borovec et al. 2013; in Czech)

83 The table shows the mesh, order mesh size and thread diameter in gillnets The size characteristics of 12-mesh gillnet: according to Norm EN 14 757 buoyancy line 30 m lead line 36 m THE MESH SIZE THREAD DIAMETER THE MESH ORDER IN GILLNET (in mm) (in mm) 10 5 0.10 3 6.25 0.10 6 8 0.10 4 10 0.12 7 12.5 0.12 9 15.5 0.15 2 19.5 0.15 8 24 0.17 12 29 0.17 The sizes and shape of the gillnet: 11 35 0.20 the European Standard gillnet consists of 12 different mesh size panels each panel has trapezoid shape 1 43 0.20 the length of each panel's buoyancy line is 2.5 m 5 55 0.25 the length of each panel's lead line is 3 m the panel lengths are equal in all types of gillnet

Table shows the mesh order, the mesh size and thread diameter in large mesh Gillnet height: gillnets according to innovations of scientists from the Institute of Hydrobiology the gillnet is longitudinally subdivided into 1.5 m high strips by row of differentiated BC AS CR, v.v.i. in České Budějovice meshes THE MESH SIZE THREAD DIAMETER the maximum gillnet height is 6 m THE MESH ORDER IN GILLNET (in mm) (in mm) the benthic gillnets are 1.5 m in height the pelagic gillnets are made in heights of 1.5, 3, 4.5 and 6 m 3 70 0.25 1 90 0.25 4 110 4 x 0.15 2 135 6 x 0.20 The size characteristics of 4-mesh gillnet: buoyancy line 40 m lead line 48 m

84 Two basic gillnet types are available Placement of the gillnet in the water column a) epipelagic gillnets; b) mesopelagic gillnets, c) bathypelagic gillnets; – benthic and pelagic d) benthic gillnets The benthic gillnets sinking gillnets – they do not float deployment on the bottom of the water body deployment without stretching the net anchorage is not needed height 1.5 m, length 30 m it is possible to attach several gillnets to make a set coupling cord is usually 30 m long coupling cord is sinking The pelagic gillnets three types of the pelagic gillnets are distinguished – epipelagic, mesopelagic and bathypelagic The epipelagic gillnets floating gillnets they are deployed on the water surface it is recommended to anchor them on both ends the length is 30 m with possible heights of 1.5, 3, 4.5 and 6 m it is possible to attach several gillnets to make a set coupling cord is usually 30 m long coupling cord is floating Placement of benthic and bathypelagic gillnets in lake and The mesopelagic gillnets reservoir habitats slowly sinking gillnet – may be deployed from water surface to any arbitrary depth the depth is regulated by a cord between float and buoyancy line deployment takes place on the water surface and the gillnet sinks to the targeted depth it is recommended to anchor on both ends of the gillnet the length is 30 m with possible heights of 1.5, 3, 4.5 and 6 m it is possible to attach several gillnets to make a set coupling cord is usually 30 m long coupling cord is sinking

The bathypelagic gillnets the deployment depth is regulated by a cord from the anchor and the lead line bathypelagic gillnets are being anchored to the bottom using two floats at both ends of the gillnet is recommended the length is 30 m with possible heights of 1.5, 3, 4.5 and 6 m creating set of several gillnets is possible coupling cord is usually 30 m long coupling cord is sinking

85 Instructions for use:

sink the gillnet finder into the water in use a row boat for finding gillnet, not the area where the gillnet was lost a motor boat extrication cord must be attached to the haul should be slow and steady the crossbar of the anchor arm after the gillnet finder entangles the net, extrication cord must be sufficiently long draw it out of water extrication cord must be 1.5 times haul the gillnet finder through an longer than the maximum depth appropriately spaced grid of the area Gillnet finder float must be attached to the extrication where you expect to find the gillnet cord when the shore steepness is larger than haul the gillnet finder on the bottom 5°, haul the gillnet finder perpendicularly Keep in mind the following ethical standards: haul the gillnet finder either by hand or to the shore a gillnet lost at depths is still fishing by boat never leave a lost gillnet in the water use our gillnet finder for finding and lifting lost gillnet Instrucitons to extricate stucked gillnet finder:

Usage: Size: finding lost nets height: 45 cm gillnets, fish traps etc. length of the arm: 20 cm diameter 12 mm Advantages: special shape preventing gillnet finder from getting stuck easy to get the gillnet finder free easy to store and use

Composition: three arm anchor made from steel poles attach the float to the hauling cord and give the cord strong tugs until the gillnet of 12 mm in diameter throw into the water finder is released hauling cord – white, 30 m drive the ship on the opposite side of drive with the boat to the side and pull extrication cord – red with float – 20 m the haul strongly the extrication cord until the grab the float with the extrication cord gillnet finder is released fully stretch the extrication cord

86 use of juvenile benthic 4 mesh size gillnets (mesh sizes 5, 6.25, 8, 10 mm, length 4 x 2.5 m, height 0.5 m)

use of pelagic and benthic 12 mesh size gillnets (for mesh sizes see table above, length 12 x 2.5 m, use of pelagic and benthic 12 mesh size gillnets (for mesh sizes see table above, length 12 x 2.5 m, height 1.5 - 4.5 m) height 1.5 - 4.5 m)

87 Underlying, enclosing and dividing nets

88 Underlying nets careful fishing from pond, channel and fish storage ponds

fishing spot inflow inflow enclosure

underlying net

pond drainage

handles

vats

Usage: Instructions for use: Composition: fishing from drained ponds lay the net on the bottom of a water body polyamide knotless net with diamond-shaped mesh fishing part of the stock from a full pond ensure that the net does not cover the fish – net has to perimeter of the underlying net is strengthened with - usually used for fry and juvenile fish be below the fish thick plaited cord fishing in rearing pools and channels anchor the net to the bottom with “handles” rope is threaded through the perimeter, the thickness - usually used for trout and other salmonids anchor the net to the shore in the case of use in is in accordance to net size fish is kept in excellent condition channels and small ponds lead line is sewn to perimeter rope lay the net in a feeding spot when used in a full pond the underlying net is divided into regular strips with Advantages of an underlying net: feed above the set net lead line fish is caught without unnecessary abrasion – damage ensure that the net is spread below the fish in a the spacing of lead line depends on the net and mesh fish stays in the water while being manipulated drained pond size fish condition and oxygen content can be checked spread the net below fish using ropes and boathooks lead line can be length- or width-oriented regularly only one orientation is possible correct use leads to catching nearly all fish at once Attention – fish can die if they are caught beneath the not necessary to fish repeatedly as with beach seine net net

89 Fry fishing with underlying net

setting the underlying net lifting the underlying net

fish concentrate in a bag remove and sort fish from the underlying net

Underlying nets are made in following widths

MATERIAL THREAD THICKNESS MESH SIZE (in mm) NET WIDTH (in mm) LENGTH PES 2 3, 6, 9,1 2,1 5 arbitrary Netting 210/4 4 4, 6, 8, 10, 15, 20 arbitrary Netting 210/9 6 4, 6, 8, 10, 15, 20 arbitrary Netting 210/18 10 6, 8, 10, 15, 20 arbitrary Netting 210/18 15 8, 10, 15, 20 arbitrary Netting 210/24 20 10, 15, 20, 25, 30 arbitrary

90 Fishing in ponds with underlying net

Enclosing and dividing nets Usage: gathering fish in space smaller than the area where fish can normally swim usually used for blocking drains and reducing available space for fish Instructions for use: Composition: anchor the lower edge of the net with “handle” using polyamide knotless net with diamond-shaped mesh rope on the perimeter the core is made from a strip of netting throw upper edge over “handle” and fix with sling rope is threaded through the net perimeter and has made from rope on the perimeter – easier to withstand slings in corners strain from fish Enclosing and dividing nets are made in these widths MATERIAL THREAD THICKNESS MESH SIZE (in mm) NET HEIGHT (in mm) LENGTH Netting 210/18 15 1.5, 2 arbitrary Netting 210/24 20 1.5, 2 arbitrary Netting 210/24 25 1.5, 2 arbitrary

91 Nets for breeding and handling

Nets for breeding and handling are also suitable for scientific research

92 Inset nets for water inflow channels and vats

these nets are used for rearing

fry immediately after hatching water outflow these nets are also used for the short-term rearing and handling water flow regulation space for water flow of fry and small fish species of water level

Inset nets for channels nets are tied to a metallic frame and put into channels nets hang freely in the channel filled with standing or flowing water coating POWDER COATING Composition: - metallic frame - inset net is made from polyamide or polyester netting - precise mesh size Net size: - available in mesh sizes: 0.1, 0.14, 0.2, 0.24, 0.34, 0.5, - width / length / depth 0.5 x 0.96 x 0.5 m 0.6, 2 mm - the mesh is attached to the frame to prevent Frame size: movement in the current - 12 mm diameter wire - cords are attached to upper and lower edge of netting - width/length 0.5 x 0.96 m for fixing to the frame - powder coating

The shape and size is made according to the customer’s requirements. 93 install inflow hose between the inset net and the vat Cage nets for rearing and metallic frame storing fish

elastic rope cage nets are made for rearing and storing fish the inflow hose must be oriented sideways to ensure water circulation in the vat the main advantage is its ease of mobility and low demands on technical equipment water flows in and out over the round vat edge

Mesh

space for water flow Inset nets to round vats inset nets are placed on the frame in the round vat nets hang freely in standing or flowing water

Composition: - metallic frame - inset net with mesh size of 2, 4 and 6 mm - elastic rope with 8 mm diameter is threaded through the edge of the inset net

Size: - diameter / depth 1.25 x 0.6m

Frame size: - 12 mm diameter wire - diameter / height 1.3 x 0.2 m - powder coating

coating POWDER COATING

94 nets for breeding and handling can be Portable floating cage supplemented with a protective net against piscivorous birds avoid damage: protective net is usually attached to a frame keep fish in good health short term fish storage selling fish

Protecting against birds

Portable floating cage can be supplemented PA PE with PE protective net with mesh size 20 / 1,5 mm 25 / 2 mm 25, 40, 45 mm Protective net has elastic rope for net attachment to a frame

PE PE PE PE 25 / 2 mm 40 / 2 mm 45 / 3 mm 70 / 3 mm lead line is attached to the lower line of the net Breeding net may consists of lead weights be equipped with and a machine made net a doubled bottom uses weights: 30, 80, 120, 160, 200 g

95 width “b“ width “c“

depth above the water level (cca 0.5 m)

Total depth “a“ water level

Submerged depth below the water level

Small floating cage nets with frame small floating cage nets may be placed in fish ponds, pools and channels and aid with manipulating, separating and storing fish to sell

Net composition: Frame composition: - polyester net with mesh size 2 mm - frame is made from hard PVC piping - polyamide net with mesh sizes 4, 6, 10 and 15 mm - diameter is 50, 100 mm or their combination - thread thickness 0.5 – 1.4 mm (210/4 – 27) - possible to detach the frame - cage consists of 4 sides and bottom - joints are sealed with rubber connectors - bottom has lead line attached along its perimeter (30 – 80 g) - possible to supplement the bottom of the inset net with smaller mesh size (2, 6 mm) Recommendation - frame is inserted into the upper edge perimeter Maximum frame size by 2 x 2 m is recommended. - net always hangs from upper edge of the frame Maximum depth by 2m of submerged net is recommended. - floats are attached to the lower part of the frame Possible to cover cage with protective net.

Example sizes of small floating cages: The shape and size is made according to the customer's requirements MATERIAL MESH SIZE (in mm) WIDTH “b, c” (in m) TOTAL DEPTH “a” (in m) HEIGHT (in m) Polyamide 0.24, 0.34, 0.5, 0.6 0.5, 1, 1.5, 2 1, 2, 3 1, 1.5, 2, 2.5 Polyester 2 0.5, 1, 1.5, 2 1, 2, 3 1, 1.5, 2, 2.5 Polyamide 4, 6, 10, 15 0.5, 1, 1.5, 2 1, 2, 3 1, 1.5, 2, 2.5 Polyethylene 25, 45 0.5, 1, 1.5, 2 1, 2, 3 1, 1.5, 2, 2.5

96 Cage nets for rearing and storing fish cage nets are made for rearing and storing fish the main advantage is its ease of mobility and low demands on technical equipment

Cage nets for rearing fish these nets are made from polyamide knotless material diamond–shaped mesh are made in size of 6, 10, 15, 20, 25 mm protective nets may be attached for protecting against birds

Cage nets for storing fish Protective nets may be attached to these nets are made from polyamide knotless material protect against birds – these nets are squared mesh are made in size of 25 and 45 mm Cage net may be equipped with a made from polyethylene in mesh size protective nets may be attached for protecting against birds doubled bottom (e.g. 15 mm + 2 mm) 3 and 100 mm

Cage net composition Example sizes of cage nets for rearing and storing fish: - the cage consists of 4 sides and bottom The shape and size is made according to the customer's requirements - the perimeter of the bottom is overcast by heavy line (80 – 160 g) MESH SIZE WIDTH DEPTH HEIGHT - the bottom may be supplemented with small mesh inset net MATERIAL - the edge of net is overcast by cord (8 – 12 mm in diameter) (in mm) (in mm) (in mm) (in mm) - the corners of net are equipped with loops for fixing Polyamide 6,10,15,20 1,2,3,4 1, 2, 3, 4, 5, 6 1.5, 2, 3, 4 Polyethylene 25, 45 1,2,3,4 1, 2, 3, 4, 5, 6 1.5, 2, 3, 4 The cage design may be adjusted according to the customer's requirements.

97 Fiberglass products and accessories for fish handling

98 Fiberglass products

Usage: easy manipulation of captured fish short-term gathering, storage and transport of fish fiberglass products are safe for fish health

Composition: products are made from polyester fibreglass do not require maintenance the inner side of products is smooth – fish are not damaged during manipulation the bottom and edges are made thicker to prevent them from wearing out

Standard round vat 550 l Products require minimum storage essential equipment for harvesting fish from space – they fit into each other so it is possible to stack them up. ponds, fish storage ponds etc. Usage: short-term fish gathering during harvesting the pond stand for sorting crate, sorting chute etc.

Advantages: low weight large volume safe for fish health possible to stack vats up for transport and storage

Composition: upper edge is made thicker along its perimeter to avoid cracks bottom is made thicker to prevent them from wearing out

size: VOLUME (in l) WEIGHT (in kg) UPPER WIDTH x LOWER WIDTH x HEIGHT (in m) 500 23 1.26 x 1.05 x 0.61

99 PE PE 25 / 2 mm 40 / 3 mm

Cover for the vat Covering net for vats Rectangular vat EUR 450 l covering the vat enables to transport keep fish in the vat without damage + cover and keep fish in the vat (jumping out) by covering the vat with It is essential equipment for every fisherman perfect fitting guaranteed - elastic rope the net Usage: is threaded through the hem Advantages: short-term gathering of captured fish prevents fish from jumping out of the vat Advantages: the size of the bottom corresponds to usual EUR pallets allows to refill and change water in the vat prevents fish from jumping out of the vat - makes manipulation of fish easier prevents fish damage prevents water from pouring out of the vat short-term transport – manipulation – cover needed prevents fish damage Composition: PE net – polyethylene, mesh size 25, 45 mm Advantages: Composition: easy manipulation of fish when the vat is placed on an fabric coated with PVC Elastic rope is threaded through the net perimeter (keeps the net firmly on the vat) EUR pallet elastic rope sewn into doubled hem cover prevents fish from jumping out during transport prevents water from pouring out of the vat prevents fish damage easy to store - possible to stack vats up for transport and storage

size: size: size: DIAMETER HEM HEIGHT DIAMETER HEM HEIGHT VOLUME WEIGHT UPPER WIDHT x LOWER MESH SIZE (in m) (in m) (in m) (in m) (in l) (in Kg) WIDHT x HEIGHT (in m) 3.2 0.1 3.20 0.1 25/2, 45/3 450 14 0.87 x 0.80 x 0.50

100 Stretcher for fishes

Usage: gentle fish transport Advantages: suitable shape for fish comfort excess water flows out through holes in the bottom easy to store and transport does not decay – easy disinfection Composition: egg-shaped metal frame with two handgrips made from fabric coated with PVC (tarpaulin) size: WIDTH (in m) LENGTH (in m) HEIGHT (in m) Standard vat 0.4 1.2 0.4 Essential equipment for harvesting fish from ponds Standard vats are made in two basic sizes – 40 and 60 Protective net for the vat prevents fish from jumping out of the vat Usage: transport of captured fish Advantages: Advantages: makes fish transport large handgrips – comfortable manipulation in the vat easier stable shape prevents fish from high load-bearing capacity jumping out of the easy to store - possible to stack vats up for transport vat and injuring and storage themselves

Composition: Composition: upper edge has a metal frame with handgrips metal frame with two handgrips bottom is made thicker to prevent from it from wearing out PE net – polyethylene, size: mesh size 25 mm size: VOLUME WEIGHT WIDTH x HEIGHT (in l) (in Kg) x LENGTH WIDTH (in m) LENGTH (in m) 40 4 0.48 x 0.30 x 0.72 0.45 0.55 60 5 0.52 x 0.32 x 0.74

101 Sorting crate Usage: hand sorting of all fish sizes and species

Stretchers Instructions for use: for maternal fish place sorting crate on two round vats Advantages: Composition: Usage: high stability in the process of sorting rectangle-shaped metal frame gentle transport of maternal fish, large fish and rare does not damage fish made from fabric coated with PVC (tarpaulin) fish species easy manipulation of fish thicker bottom prevents from tearing it Advantages: easy to store - possible to stack vats up for transport excess water flows out through holes in the bottom special cut and shape which prevents fish from and storage jumping out of the stretchers does not decay – easy disinfection water and anaesthetics do not splash out of the stretchers easy to store and transport does not decay – easy disinfection

Composition: made from fabric coated with PVC (tarpaulin) two removable poles – handgrips possible to order without poles – handgrips handgrips – diameter 3.8 cm, length 180 cm

size: WIDTH HEIGHT LENGHT size: (in m) (in m) (in m) WIDTH (in m) WIDTH (in m) HEIGHT (in m) 0.5 0.50 1.5 0.80 0.75 0.35

102 Chute A + extension B Tube net for fish stocking Usage: Advantages: Usage: stocking of fish from transport vats into long-lasting product – wear-resistant gentle fish stocking from transport vats into ponds, fish storage ponds, streams etc. rearing ponds, pools, channels, ponds useful for both sorting and stocking fish fast fish sorting by several people fast and easy manipulation Instructions for use: effective fish stocking and sorting place the hose clamp of the tube net on Instructions for use: the outlet tube fish stocking: place chute oriented with its Composition: tighten hose clamp precisely broad end to the outlet of a transport vat chute A can be used separately; broad put the opposite end of tube net into water - place chute on the tipped body of the end has two projections – designed for remove the divider from the vat truck placing at the opening of the transport vat water with fish flows into the pond - place chute into prepared holds extension B is only an extension for join chute A and extension B by sliding chute A and cannot be used separately Advantages: chute into the extension gentle stocking – releasing fish from the fast fish sorting: place chute on the vats transport vat standing in a row fish do not jump out, do not fall on the ground easy to store – tube net is collapsible, does not require much space does not decay – easy disinfection

Composition: hose clamp used to attaching the tube net on the outlet tube shackle used for attaching tube net on the hose clamp net tube made from fabric coated with PVC

CHUTE LENGHT (in m) WEIGHT (in Kg) size: chute A 3 10 WIDTH (in m) HEIGHT (in m) LENGTH (in m) exstention B 2 8 0.65 0.30 4 / 5 / 6

103 Ropes and cords + buoyancy and lead lines

104 We make and sell plaited cords and ropes

PA - Polyamide PES - Polyester PP - Polypropylene

Ropes and cords made from these materials are: elastic firm do not decay abrasion resistant weatherproof

Do not use these ropes and cords in any situation for smooth knitting with cross knitting active or passive belaying, cross knitting with core core they are not climbing ropes! smooth knitting

three strands twisted rope

Packing of ropes and cords

reel (10 – 30 m) mini bundle (30 – 50 m) bulk in bag (0,2 – 5 kg) Bündel von 3 – 5 kg bobbin 1 – 3 kg

105 Ropes and cords plaited from polyamide (PA) PA rope – smooth knitting DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) Polyamide is used in fishery for its useful material characteristics. 1.2 27 0.62 1.4 32 1 Usage: 1.8 60 1.62 net attachment to a frame – used for small handling equipment 2 80 1.68 repairing damaged net 2 floats and buoys attachment 90 1.88 towing and draught ropes attachment to nets (dip net cord) binding ropes for boats 2.5 150 2.78 Characteristics: 3 190 3.46 3 high strength, elasticity 200 3.6 high stretchability (dip net cord) high durability against abrasion 4 300 5.24 endure higher temperature than PP, working temperature to 100°C 5 400 6.98 fusing point 215°C do not float, become hard in water soaked and tightened knots cannot be untied heavier in comparison to PP (soaked or dry) PA cord – cross knitting lower endurance to feces and acids DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) Colors: 2 170 3.7 ropes and cords are usually made from PA in white or black color 3 240 6.02 4 340 8.5 5 420 10.54 The stated strength values are approximate and may differ slightly between products. 6 570 15.8

PA rope – smooth knitting DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) 4 550 11.5 6 900 22.4 8 1300 36.06 10 2300 56.92

106 Making nets in ten steps – use cord made from PA material

107 Ropes and cords from PES (polyester) PES cord – smooth knitting without core high strength, low elasticity and weatherproof DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) Usage: 3 190 4.16 draught ropes to nets anchor ropes 4 260 6.12 lifting and casting ropes 5 350 8.5 ropes for tackles water sports 6 420 10.7 outdoor and indoor usage Characteristics: high strength PES cord – cross knitting without core low elasticity DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) soft in water 3 210 7.1 do not float UV resistant 4 280 9.62 working temperature up to 150 °C (softening point 225 °C, fusing point 260 °C) 5 380 11.7 good resistance to chemicals 6 450 16.06 Plaited cords without core can have knitted loop at the end. Colors: ropes and cords from PES are made in white color PES rope – smooth knitting with core DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) 6 700 30 The stated strength values are approximate and may differ slightly 8 940 41.5 between products. 10 1700 62.5 12 2200 93.5 14 3200 137.0

108 Supplements of 16 strand cords:

knitted loop at the end of the rope knitted loop at both ends of the rope knitted into an infinite loop possible to strengthen loop with internal ring possible to add ring to the loop the rope strength decreases by approximately 10 % with the presence of a loop PES cord – cross knitting without core – possible to make knitted DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / m) 6.5 600 22.12 rope end knitted rope end knitted Rope knitted into infinite loop 8 1000 32.8 into loop into loop with inner metal ring 10 1500 53.12 12 2100 82.8

Three strands twisted ropes Three strand twisted rope from PA – polyamide from PES - polyester Colors Suitable as anchor or binding rope. Suitable as anchor or binding rope. twisted ropes from PA and PES are made in white color Characteristics: Characteristics: high elasticity and energy absorption soft when used in water high strength high strength durability against abrasion resistant to abrasion Supplements: Supplements: knitted loop at the end of the rope knitted loop at the end of the rope knitted loop at both ends of the rope knitted loop at both ends of the rope knitted into an infinite loop knitted into an infinite loop possible to strengthen loop with internal ring possible to strengthen loop with internal ring possible to add ring to the loop possible to add ring to the loop the rope strength decreases by approximately 15 % the rope strength decreases by approximately 10 % with the presence of a knitted loop with the presence of a loop PES three strand twisted rope PES three strand twisted rope DIAMETER APPROXIMATE WEIGHT DIAMETER APPROXIMATE WEIGHT (in mm) STRENGTH (in kg) (g / m) (in mm) STRENGTH (in kg) (g / m) 6 800 22.2 15 3200 145 8 1400 39.5 The stated strength values are approximate and 10 2150 61.7 may differ slightly between products. 12 2600 88.8

109 Ropes and cords made from PP polypropylene PP cord – smooth knitting without core DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) highly resistant to chemicals, float on the water, elastic 3 95 1.98

Characteristics: 4 170 4.4 water resistant, zero absorbability, float on the water 5 220 6.48 lower weight in comparison with pa and pes material 6 330 8.5 resistant to chemicals same features in dry and wet condition – bendability, softness 9 700 22 knot – possible to untie even in wet conditions good insulating power lower resistance to abrasion lower resistance to high temperature, use up to 80°c PP cord – cross knitting without core fusing point 170°c DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) 3 95 2.16 Usage: water sports – paddling, yachting, boats, ships 4 170 4.6 animal farming – head collars, leashes for dogs 5 220 7.8 building industry 6 330 9.1 industry production textile, advertising and decorative industry 7 410 11.8 sport equipment, skipping ropes, towing equipment 8 640 22.8 outdoor and indoor usage

Colors: PP rope – smooth knitting with core Ropes and cords from PP are made in basic pastel colors and their combinations DIAMETER (in mm) APPROXIMATE STRENGTH (in kg) WEIGHT (g / lm) 6 600 18.76 8 850 28.8 The stated strength values are approximate and may differ slightly between products.

floats – suitable for rescue every boat needs a rope sets – “cast bag”

110 Floats for nets Lead line to buoy the net in the water Keeps the lower line of the net to mark the position of the net close to the bottom.

Usage: Usage: the cord is threaded through the float lead line is threaded through the and sewn to the net net or sewn to the perimeter rope float size – bearing capacity weight of the lead line determines determines float use its use

Composition: lead core sewn into threads from PA – float in heavy design of the net polyamide, PES – polyester, PP - polypropylene

float in light design of the net

DIAMETER (in mm) LENGTH (in mm) BEARING CAPACITY (in g) 40 65 60 50 90 105 65 100 230 68 150 315 WEIGHT 10 g / lm 30 g / lm 80 g / lm 120 g / lm 160 g / lm 200 g / lm

Elastic rope Usage: Threaded through the net on the perimeter Strength and firmness of net holding depends on: elastic rope thickness tightening – shortening of elastic rope around the perimeter Composition: rubber core surface knitted from threads PES – polyester or PP - polypropylene vat cover cover for fish storage DIAMETER 3 mm 4 mm 5 mm 6 mm 8 mm 10 mm cage

111 Protective nets

Protect your fish farm against piscivorous birds and sun.

112 Protective netting “Unpack and hang” set includes: against piscivorous birds Steel wire Complete set – Protect your fish farm against piscivorous birds and sun includes all material – easily and effortlessly. needed for hanging the net Usage: Usage: fish farming covering rearing channels and pools ornamental fish and other water animal farming covering ponds, tanks, cages, flumes etc. juvenile fish farming shading fish farms in channels Stretching screws PVC coated steel wire salmonid fish farming in channels, cages and ponds shading channels and farming tanks

Wire mesh cannot be replaced by protective netting !!!

Clips Snap-hooks

Possible to roll the protective net on the steel wire perimeter.

Pliers for fastening Fastening wire clips wire clips

Options of protective nets: net in recommended size separately – protective net without accessories PP cord for attaching Cable ties in a set ready to use – “unpack and hang” – with all components needed

Protective net placement: on water surface on the structure– e.g. cages, channels, structures made from steel wire support the nets with simple wooden props in shape of “T” hang them on firm structures attached with steel wire for year-long use

113 PE PE PE PE Protective nets 25 / 2 mm 40 / 2 mm 45 / 3 mm 70 / 3 mm made from PE - polyethylene Long-lasting and reasonably priced

characterized by low weight low elasticity weather resistant MATERIAL MESH SIZE (in mm) THREAD THICKNESS WEIGHT COLOR hydrophobic material – does not absorb water 2 does not change character in water – does not decay PE - polyethylene 25 2 120 g/m lightweight and sturdy PE - polyethylene 40 2 75 g/m2 suitable for large areas and heights PE - polyethylene 45 3 125 g/m2 PE - polyethylene 70 3 83 g/m2 PE - polyethylene 100 3 60 g/m2

114 Protective nets Protective nets made from PA - polyamide made from PP – polypropylene strips Soft and easy to store Protect your fish against sun

extremely durable highly resistant against UV light highly elastic weather-resistant weather-resistant does not change character in water – does not decay does not change character in water – does not decay suitable for shading of channels, pools suitable for covering channels, pools, vats SHADING PA PA PA MATERIAL WEIGHT COLOR 20 / 1.5 mm 40 / 1.2 mm 40 / 2 mm EFFICIENCY PP – polypropylene strip 65% 115 g/m2 PP – polypropylene strip 75% 125 g/m2

MESH SIZE THREAD MATERIAL WEIGHT COLOR (in mm) THICKNESS PA - polyamide 20 1.5 125 g/m2 PA - polyamide 40 1.2 40 g/m2 Hang the net attaching snap 2 PA - polyamide 40 2 122 g/m hooks on the steel wire

steel bar

possible to roll the net in all directions

Bind the net around the fixed construction The net has lead line (cord is tied into each mesh)

115 Aviary nets – easily and effortlessly

Give your farmed flock safety, freedom and the joy of movement.

Usage: Protective nets attachment of the net to the wire mesh improves bird farming – their condition and health provides freedom of movement to your flock – which made from PE - polyethylene improves growth and appearance Long-lasting and reasonably priced protects from attack of avian predators PE PE PE PE protects from unwelcome feeding of wild birds from characterised by low weight 25 / 2 mm 40 / 2 mm 45 / 3 mm 70 / 3 mm surroundings (saves food) low elasticity protects from disease transfer from surroundings weather resistant hydrophobic material very light Wire mesh cannot be replaced by protective suitable for large areas and heights netting !!! MATERIAL MESH SIZE (in mm) THREAD THICKNESS WEIGHT COLOR PE - polyethylene 25 2 120 g/m2 Options of protective nets: PE - polyethylene 40 2 75 g/m2 net in recommended size separately – protective net without accessories PE - polyethylene 45 3 125 g/m2 in a set ready to use – “unpack and hang” – with all PE - polyethylene 70 3 83 g/m2 components needed PE - polyethylene 100 3 60 g/m2

Protective net placement: Protective nets – support them with simple wooden props in a T-shape Remove props in the winter and lie nets on the ground Protective nets – hang them on solid structures and attach with steel wire use them all year long

116 Pokorný - Sítě s.r.o. Brloh 117 382 06 Brloh Česká Republika 48°55‘42.103“N, 14°13‘13.657“E

text: Petr Pokorný translated and edited by: Marek Smejkal graphic design and illustrations: Tomáš Tupý photographs: archive of the Pokorný – Sítě s. r. o. and Biology Centre AS CR, v.v.i. Institute of Hydrobiology

All information contained herein is sole property of the Pokorný – Sítě s. r. o. and Biology Centre AS CR, v.v.i. Institute of Hydrobiology. All photographs contained herein are sole property of the Pokorný – Sítě s. r. o. and Biology Centre AS CR, v.v.i. Institute of Hydrobiology. All drawings contained herein are sole property of the Pokorný – Sítě s. r. o. Tomáš Tupý Marek Smejkal No part may be published without the consent of the Pokorný – Sítě s.r.o. graphic design and illustration translation and stylistic revision Berlin

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Pokorný - Sítě s.r.o. Brloh 117 Praha 382 06 Brloh Nürnberg Czech Republic Czech Republic

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