EFFUSE - Scientific education for advanced

PAVOL JOZEF ŠAFÁRIK UNIVERSITY IN KOŠICE Faculty of Science EFFUSE – Scientific education for advanced EFFUSE team of authors Košice 2025 This educational material was produced with the financial support of the European Union within the project HUSKROUA/1901/6.1/0075 “Environment for the Future by Scientific Education” (EFFUSE) of ENI CBC Programme Hungary-Slovakia-RomaniaUkraine 2014-2020. Its contents are the sole responsibility of Pavol Jozef Šafárik University in Košice and do not necessarily reflect the views of the European Union. More information on the project is available on the links below: https://effuse.science.upjs.sk/index.php/en/ EFFUSE team of authors EFFUSE - scientific education for advanced Educational text Authors: RNDr. Ivana Slepáková, PhD. Department of Microbiology, Faculty of Science, PJ Šafárik University in Košice RNDr. Monika Balogová, PhD. Department of Zoology, Faculty of Science, PJ Šafárik University in Košice RNDr. Natália Pipová, PhD. Department of Animal Physiology, Faculty of Science, PJ Šafárik University in Košice doc. RNDr. Andrej Mock, PhD. Department of Zoology, Faculty of Science, PJ Šafárik University in Košice RNDr. Peter Ľuptáčik, PhD. Department of Zoology, Faculty of Science, PJ Šafárik University in Košice RNDr. Mariana Kolesárová, PhD. Department of Microbiology, Faculty of Science, PJ Šafárik University in Košice RNDr. Lenka Maliničová, PhD. Department of Microbiology, Faculty of Science, PJ Šafárik University in Košice prof. RNDr. Martin Bačkor, DrSc. Department of Plant Biology, Faculty of Science, PJ Šafárik University in Košice doc. RNDr. Yaroslava Hasynets, PhD. Department of Botany, Faculty of Biology, Uzhhorod National University doc. RNDr. Vladyslav Mirutenko. PhD Department of Entomology and Biodiversity Conservation, Faculty of Biology, Uzhhorod National University doc. RNDr. Roman Kish, PhD. Department of Botany, Faculty of Biology, Uzhhorod National University doc. RNDr. Mykhailo Vakerych, PhD. Department of Genetics, Plant Physiology and Microbiology, Faculty of Biology, Uzhhorod National University prof. RNDr. Maryna Kryvtsova, Dr.Sc. Department of Genetics, Plant Physiology and Microbiology, Faculty of Biology, Uzhhorod National University doc. RNDr. Fedir Kurtyak, PhD. Department of Zoology, Faculty of Biology, Uzhhorod National University doc. RNDr. Alexander Mateleshko, PhD. Department of Entomology and Biodiversity Conservation, Faculty of Biology, Uzhhorod National University RNDr. Andrea Ivanová Gymnázium Pavla Horova, Michalovce Editor: RNDr. Beáta Valkay, PhD. This text is published under the Creative Commons 4.0 license - CC BY-NC-SA ("AttributionNonCommercial-ShareAlike"). The authors are responsible for the professional and linguistic aspects of this publication. The manuscript has not undergone editorial or linguistic editing. Available at: www.unibook.upjs.sk Publication date: 21.10.2025 DOI: https://doi.org/10.33542/EFF-0448-4 ISBN 978-80-574-0448-4 (e-publication) CONTENTS 1 INTRODUCTION .............................................................................................. 4 2 FISH AS INDICATORS - subject of scientific education ............................... 5 2.1 Fish Morfology .................................................................................................................... 5 2.2 Fish as Bioindicators in Aquatic Ecosystems ........................................................ 11 5.1 Fish - Tasks to Practice .................................................................................................. 16 5.2 Field Task ............................................................................................................................ 26 3 AMPHIBIANS AS INDICATORS - subject of scientific education ............... 27 3.1 Amphibians Morfology and Physiology .................................................................. 27 3.2 Amphibians Species ....................................................................................................... 32 3.3 Amphibians as Bioindicators of Water Quality .................................................... 44 Phenotypic Structure of Amphibian Populations ................................................ 45 Morphological indicators of amphibians against anthropopressure .............. 46 Teratogenesis in Amphibian Populations ............................................................. 47 Developmental Stability .......................................................................................... 47 Summary: ................................................................................................................... 47 3.4 Amphibians - Tasks to Practice ................................................................................. 48 3.4 Amphibians - Field Tasks ............................................................................................. 59 4 HABITATS AS INDICATORS – subject of scientific education .................... 65 4.1 Aquatic, Riparian, and Wetland Plants and Habitats as Indicators of Water Body Status ....................................................................................................................... 65 Rules of assessment ................................................................................................ 67 5 SUSTAINABLE DEVELOPMENT and scientific education ........................... 69 5.1 MODUL Theoretical and Practical Backround ...................................................... 71 5.2 MODUL Global Water Issues ...................................................................................... 82 5.3 MODUL Sustainable development ........................................................................... 89 6 ANNEX ........................................................................................................... 96 4 1 INTRODUCTION Living objects in the riverscape offer many opportunities for science education and research. The river ecosystem is dynamic and supports diverse life forms, each of which plays a key role in the ecological balance. Different species of aquatic plants, algae and phytoplankton can be studied in terms of their adaptation to aquatic life, understanding the process of photosynthesis and water filtration processes and the basis of aquatic food webs and their role in maintaining the ecosystem. Aquatic invertebrates, such as insects (horseshoe crabs, dragonflies), crustaceans (crayfish), molluscs (snails, bivalves) and invertebrates (leeches, aquatic worms), are essential for understanding food webs, biodiversity and the health of the river ecosystem. They are also indicators of water quality. The study of different fish species can provide insights into their life cycle, breeding habits, survival patterns and adaptive mechanisms. Fish species vary depending on the river environment and are key to the study of ecology, evolutionary biology and conservation science. They can also serve as bioindicators of the ecological health of a river. Amphibians and reptiles that inhabit river environments can be studied in terms of their life cycles, their adaptation to aquatic and terrestrial environments and also as indicators of the environmental health of the environment and its pollution. Of course, many other groups of vertebrates also live near rivers. In this publication, we focus in more detail on the fish and amphibians. Their requirements on the environment are characteristic and many species of these vertebrates are protected. This is why systematic scientific education is essential for understanding their bioindicator role. The publication includes a separate chapter, devoted to present a perspective on science education towards sustainable development, as this global topic is largely absent in the curricula in Slovakia and Ukraine. EFFUSE team 5 2 FISH AS INDICATORS - subject of scientific education Fish (Actinopterygii) are a diverse group of vertebrates that should be studied extensively in the field of scientific education. They are an important model organism for studying various biological processes. Importance of education about fish stems from the need: • understanding the role of fish in aquatic ecosystems • importance of fish conservation and sustainable fishing practices • learning about fish biology, behavior, and habitat requirements 2.1 Fish Morfology The body of fish can be divided into the head (caput), trunk (truncus), and tail (cauda). Depending on the environment in which they live, the shape of the fish's body can vary. Species inhabiting swiftly flowing waters have a torpedo-shaped body to minimize resistance to the current (e.g., brown trout - Salmo trutta morpha fario, grayling - Thymallus thymallus). Fish living in stagnant or slowly flowing waters with vegetation have a tall and laterally flattened body, allowing them to maneuver skillfully among various obstacles (e.g., common bream - Abramis brama, rudd - Scardinius erythropthalmus). Fish that dwell near the bottom often have a flattened upper body, such as the wels catfish (Silurus glanis), or even completely flat, as seen in flatfish from the Pleuronectidae family. Predatory fish, like the northern pike (Esox lucius), have a cylindrical, torpedo-shaped, or fusiform body, with the dorsal and anal fins shifted toward the tail, enabling them to make a strong strike and quickly dart after prey. Fins serve as the locomotor organs of fish. On their body (Fig. 1), we can observe unpaired fins (dorsal fin - pinna dorsalis (1), caudal fin - p. caudalis (2), and anal fin – p. analis (3)) and paired fins (ventral fins – p. ventrales (4), pectoral fins – p. pectorales (5)). In salmonid fish or invasive catfish of the Ameiurus genus, there is also a so-called adipose fin (pinna adiposa), but unlike the previous fins, it is not supported by rays; it consists of connective tissue. Various positions of ventral fins are recognized. They can be located anterior to the pectoral fins, known as jugular position, found, for example, in the freshwater burbot (Lota lota). In the thoracic position, they are situated directly beneath or just behind the pectoral fins, typical for perch-like fish (e.g., Perca fluviatilis), and in the abdominal position, they are placed behind the pectoral fins, approximately halfway along the body, a characteristic position for carp-like fish (e.g., Cyprinus carpio). 6 In the course of evolution, some species have experienced fusion of certain fins, such as the ventral fins, into a single unpaired ventral adhesive disc (e.g., in the European bullhead - Ponticola kessleri), or fins may be entirely absent (as in the European eel - Anguilla anguilla). Fins are reinforced at the front by hard, unbranched rays, also known as spines or thorns. Such strong, prominent spines can be found, for example, in the invasive brown bullhead catfish (Ameirus nebulosus) at the beginning of the dorsal and pectoral fins, where they are connected to a venom gland. Therefore, handling this fish should be done with caution to avoid injury. Soft branched rays are located behind the hard rays and are soft to the touch (Fig. 2). The length of fins and the number of rays are important characteristics used in species identification. Fig. 1. Fish body structure with indicated basic structures. 1. Dorsal fin – pinna dorsalis, 2. Caudal fin – p. caudalis, 3. Anal fin – p. analis, 4. Ventral fin – p. ventralis, 5. Pectoral fin – p. pectoralis, 6. Operculum – skrela, 7. Barbels, 8. Lateral line – linea lateralis. Fig. 2. Fin composed of rays. A. Soft rays branched at the apical end, B. Hard rays without branching. On the sides of fish heads, there are opercular bones (screles) (6) that cover the gill cavity, protecting the gills. In the corners of the mouth, on the chin, or on the snout, barbels (7) may be present. These are often found in species that live near the bottom or search for food there, such as common carp (Cyprinus carpio), wels catfish (Silurus glanis), or stone loach (Barbatula barbatula). Sensory receptors located on the barbels significantly aid them in this foraging. The presence/absence of barbels and their number are also important identification features. 7 There are various types of caudal fins. The heterocercal fin, found, for example, in the sterlet (Acipenser ruthenus), has asymmetrical lobes, with the upper lobe being noticeably longer than the lower one. An important characteristic is that the vertebral column extends into the upper lobe of the fin. The homocercal fin is externally symmetrical, composed of two equally sized lobes, but internally it is asymmetrical. The terminal part of the vertebral column is bent upward, and during development, the dorsal lobe of the caudal fin is lost, and the ventral lobe is divided into two equal parts, making the fin a purely ventral structure. This type is the most common caudal fin type in bony fish, such as the gudgeon (Gobio gobio). In the diphycercal fin, the vertebral column extends straight back to the end of the body, and the fin develops symmetrically above and below it. A typical fish with this type of fin is the Senegal bichir (Polypterus senegalus) (Fig. 3). Fig. 3. Basic Types of Caudal Fins. A. Heterocercal, fin B. Homocercal fin, C. Diphycercal fin On the side of the body, there is the lateral line (linea lateralis) (8), which is a crucial sensory organ for fish. Through it, they can detect water movements caused by the presence of other fish, objects, or obstacles in the vicinity, allowing them to 14 important environmental factors influencing the frequency and degree of manifestation of these anomalies include temperature, excessive or deficient fish feed supply, gas regime in the water body, water pH, and pollution levels. The presence of phenodeviants in the population can be considered an indirect indicator of a decrease in genetic diversity and homeostasis of development. Genes or combinations of genes that do not manifest themselves in a wellbalanced genotype and optimal living conditions are determined when there is a disturbance in genetic balance and an unfavorable environment. A large number of asymmetrical manifestations in fish indicate a decrease in the viability of their natural populations under the influence of powerful anthropogenic pressure, including pollution, and can be used as indicative indicators of environmental conditions. Skeletal Anomalies. The Connection Between the Frequency of Skeletal Anomalies in Aquatic Vertebrates and Pollution Has Been Experimentally Confirmed. For example, the chloroorganic pesticide Kepon induced scoliosis in minnows, while exposure to heavy metals in fish resulted in spine deformities and fractures. Therefore, monitoring involves a careful examination of fish to detect obvious anomalies, with possible further X-ray examination to identify hidden deformations, such as vertebral fusions. It is challenging to survey gill rakers and dorsal fins. Planktonic and zooplankton samples can be beneficial for detecting pathologies in larvae and anomalies in young fish. The number of cases of skeletal anomalies in fish increases every year. Examples of anomalies include dorsal fusions and distortions, vertebral compression (flattening), head abnormalities, and fin anomalies. Such disturbances are found in most natural populations, but they are most commonly observed in polluted waters. Skin Ulcers, observed in many fish species, are often referred to as "ulcerative syndrome." The main cause of ulcer development in fish is a high level of water pollution with hydrocarbons and an increase in populations of microorganisms potentially pathogenic to fish. The percentage of diseased fish is higher in the spring, so the season should be taken into account when fishing for monitoring purposes. Additionally, microbiological tests should be conducted on samples taken from bottom sediments and the water column. Fin Erosion is one of the most common fish diseases, clearly linked to pollution. 15 The causes of erosion are complex and may include chemical agents affecting the epithelium, a deficit of dissolved oxygen in the water, and secondary bacterial infection. Systematic bacterial infection is not necessarily linked to fin erosion, although many bacterial species can be isolated from a sample taken from the ulcer. Monitoring this indicator is recommended, taking into account the season, fish size, species sensitivity, living conditions, and migration. Tumors are found in almost all fish species, and they often have an infectious nature. Tumors can be caused by extreme water pollution and viral infections. There is also evidence that contamination with aflatoxin can induce liver tumors in minnows. Fish tumors are potentially useful indicators for monitoring the aquatic environment. 5. Species and Taxonomic Diversity. Information on the taxonomic diversity of functional groups of hydrobionts is an indicator of environmental conditions. The species and taxonomic diversity will have maximum values for certain average water quality indicators and will decrease towards very clean, oligotrophic, oligosaprobic, very dirty hypertrophic, and polysaprobic water bodies. It should also be noted that the diversity of fish species depends on many hydrological, hydrobiological, hydrochemical, and other factors. Among the most important are factors such as current strength, depth, transparency, salinity, gas regime, food base, etc. All the factors mentioned above have both direct and indirect effects on specific species and overall, on the structure of ichthyocenosis. It is known that the relationship between diversity and stability of ecosystems is sometimes contradictory. The stability of biosystems increases with an increase in diversity, but at the same time, it is noted that diversity itself is formed at the expense of ecosystem stability. In this way, as a result of analyzing various approaches in the field of water quality bioindication and the state of hydroecosystems, it should be noted that the perspective of using ichthyological indicators is evident. They are advisable to use as bioindicators at the population and cenotic levels. At the population level, the following indicators are promising for bioindication: - size diversity of population individuals using the variation index; size-weight structure of the population with indicators of average long-term data on length or body mass; gender structure with indicators of increasing or decreasing the proportion of individuals of one sex; individual morphological variability of individuals and the number of phenodeviations. At the cenotic level, it is advisable to use indicators such as the number of fish species, diversity indices, and the diversity of fish with different degrees of stenoand eurybionticity. 16 5.1 Fish - Tasks to Practice Task 1. Name the structures marked in the picture in both Slovak and scientific terms. 1. ............................................................................ 2. ............................................................................ 3. ............................................................................ 4. ............................................................................ 5. ............................................................................ 6. ............................................................................ 7. ............................................................................ 8. ............................................................................ Task 2. What is a homocercic and heterocercic caudal fin. Try to explain and draw. Also give an example of a fish species in which the type of fin is found. homocercic heterocercic 17 Task 3. Professionally name the types of oral openings according to their orientation. For each type, give one example of the species, the method of food intake and the food category (phytophagous, zoophagous, omniphagous). a. .................................................................................. b. .................................................................................. c. .................................................................................. Task 4. Match each fish with its technical scientific name and the position of its pelvic fins. A. ............................................................................................................... Correct answer: Barbus barbus 18 B. ............................................................................................................. Correct answer: Perca fluviatilis C. .............................................................................................................. Correct answer: Lota lota 19 D. Which orders fish have the adipose fin and try to draw it in the picture. ............................................................................................................ Task 5. Name the parts marked on the picture that make up the fin. a. ........................................................ b. ........................................................ Task 6. What is the professional name for the scales fish depicted in the pictures? Assign each to a fish species in which they occur. A B C 20 a. ........................................................................ b. ........................................................................ c. ........................................................................ Task 7. What is the structure marked in the picture called, and what is its purpose? ............................................................................................................................................... ............................................................................................................................................... Task 8. Using identification keys and fish atlases, assign the correct scientific and Slovak names of the order and specific species to each fish image. In the table (Table: Fish Orders), write down the identified fish orders under the images and try to list the basic characteristics that are characteristic for them using literature. (Note: The specific names and characteristics would depend on the actual content provided in the images and the literature you are referring to.) 21 A. .................................................................................... B. ....................................................................................... 22 C. ........................................................................................ D. .............................................................................................. 23 E. ......................................................................................... F. ............................................................................................ 30 The eggs of amphibians are anamniotic, lacking internal embryonic membranes (amnion, chorion, allantois), and without a shell, which is present in other tetrapod eggs. Amphibian eggs are surrounded by various gelatinous layers and are highly susceptible to desiccation. Therefore, eggs are always laid either in a moist terrestrial environment or directly into the aquatic environment. Our amphibians exclusively lay eggs in aquatic environments, either individually (e.g., newts), in the form of strings (toads from the Bufonidae family), or clusters (genus Pelophylax, Bombina, Hyla) (Fig. 2). The shape and size of the egg clutch, the way they are positioned in the environment (attached to vegetation or not), the type of aquatic environment where they are laid (larger/smaller water body, permanent/temporary, etc.) can provide valuable information about the species responsible for laying them. Therefore, these developmental stages, along with tadpoles/larvae, which are morphologically different among species, can be very helpful in monitoring species composition. Fig. 2. String-like egg clutch of the common toad (Bufo bufo) and cluster of the common frog (genus Rana). For all our amphibians, indirect development with a larval stage is typical from an ontogenetic perspective. The larval development usually takes place in water and concludes with metamorphosis when the immature young individual (juvenile) loses larval characteristics and transitions to land, where it mainly breathes air through relatively undeveloped lungs. The larval stages of our amphibians breathe through gills. In addition to these organs, the skin of amphibians plays a significant role in breathing in this group of vertebrates (60 – 80%, Zwach 1990), as it is permeable to respiratory gases and water. During the hibernation period, it ensures up to 100% gas exchange. The highly permeable 31 skin allows them to absorb water effectively from the surroundings, but at the same time, it poses a risk of rapid water loss. The skin's surface is moist due to secretions from mucous glands and is densely covered with a network of blood capillaries. In addition to these glands, amphibians also have toxic glands with external secretion. They are scattered either irregularly or clustered into structures, which can be seen as raised formations behind the eyes (parotoids – poison glands, e.g., toads, salamanders) (Fig. 3). These toxins serve amphibians not only for protection against danger but also against parasites and various skin diseases, such as fungal infections. Fig. 3. Parotoid glands in the fire salamander (Salamandra salamandra). Frogs have a developed chest bone (sternum), and they usually lack ribs, whereas in salamanders, it is the opposite. A crucial feature in the frog skeleton is the fused bones radius and ulna (radioulna - os antebrachii) in the forelimb and tibia and fibula (tibiofibula, os cruris) in the hindlimb. Another distinctive feature is the termination of the spine with a long rod-like bone (urostyle), which formed by the fusion of several terminal vertebrae (Fig. 6). These bones, preserved in pellets, reveal the presence of amphibians in the diet of predators. 32 Fig. 6. Frog skeleton. A. os antebrachii, B. os cruris, C. urostyl. 3.2 Amphibians Species Fire Salamander (Salamandra salamandra) is only representative of the genus Salamandra in Slovakia territory. Together with all newts, we classify it into the family Salamandridae. It inhabits moist deciduous or mixed forests, especially beech forests. Behind the eyes, there are parotid poison glands through which it releases a toxic secretion in danger (Fig. 5). Pores through which it releases the toxic secretion are also present in two lines on both sides of the spine from the end of the head to the end of the tail. Males do not have as pronounced secondary sexual characteristics (e.g., crests, colorful markings) as newts do. Therefore, determining the gender of this species can sometimes be complicated. Males differ from females by longer limbs and a slender body. Females, on the other hand, have a wider head. The most significant difference is observed in the shape of the cloaca. In males, it is swollen compared to the flat shape in females (Fig. 7b, c). However, sometimes it is not possible to determine the gender of a salamander unequivocally based on this determination feature. The female does not lay eggs; instead, after indirect internal fertilization (see above), the eggs develop in her reproductive tracts, and she lays well-developed larvae (still in egg cases). These larvae are laid primarily in streams or small pools. 33 Fig. 7. A. Fire Salamander found during hibernation in a mine near Ružín; B. Flat shape of the cloaca in a female; C. Swollen shape of the cloaca in a male. All our newt species are oviparous. They lay eggs individually, either attaching them freely to aquatic vegetation or "wrapping" them in the leaves of aquatic plants. The cloaca of males is much more swollen and pigmented compared to females (Fig. 8). In the spring, during the breeding season, newts are in the socalled aquatic phase, later in the summer and autumn, they live terrestrially (terrestrial phase). Two species, the Danube crested newt (Triturus dobrogicus) and the great crested newt (Triturus cristatus), are classified as "large newts," characterized by a much more robust body compared to the genera Lissotriton and Ichthyosaura. In the Czech Republic, the smooth newt (Triturus vulgaris) is also included in this category. Fig. 8. Comparison of the cloaca of a female (left) and a male (right) of the Carpathian newt (Lissotriton montandoni). 34 The great crested newt (Triturus cristatus) has a gray-brown to brown-black colored body from above with large oval dark spots and small white dots on the sides. The belly is yellow to orange, also with large dark spots. In the aquatic phase, males have a large toothed crest, which is interrupted in the pelvic area and starts from the eye level. The crest continues onto the tail, with a noticeable pearly white to silver stripe running along the center of the tail. This species has longer limbs, and when the front and hind limbs are laid longitudinally, they touch each other. The Danube crested newt (Triturus dobrogicus) is very similar to the previous species (Fig. 9). However, the body is slimmer, and the limbs are more delicate. When the front and hind limbs are laid longitudinally, they cannot touch each other (Fig. 10). The back is light brown, light greenish-brown, gray-brown to brownblack. The sides are often dotted with white dots and dark round spots. The ventral side ranges in color from bright yellow through orange to red, with dark spots. During the breeding season, the male has a prominent crest on the dorsal side, reaching up to eye level, interrupted in the pelvic area. A distinct edge continues onto the tail, and in the central part, a bluish stripe with a pearly sheen can be observed (Fig. 11). In places of common occurrence, the Danube crested newt and the great crested newt can interbreed. Fig. 9. Danube crested newts rescued from a vertical shaft in a field near the village of Streda nad Bodrogom. 35 Fig. 10. Visual representation of the longitudinal alignment of the front and hind limbs in the Danube crested newt. Fig. 11. Bluish stripe with iridescent shimmer in the middle of the tail in the Danube crested newt at the Streda nad Bodrogom site. Alpine newt (Ichthyosaura alpestris) – The male has a dark gray to dark brown color on the back, with a low black-yellow stripe running through the center and a blueish tint on the sides, along with irregularly shaped black spots (Fig. 12). The belly is red without dark spots. Females are less brightly colored, with a marbled pattern on the back, and the belly is without spots (Fig. 13). 36 Fig. 12. Male Alpine newt discovered in the Ćićarija mountain range (Croatia). Fig. 13. Male (left) and female (right) Alpine newt in the Czech Republic. 3. The smooth newt (Lissotriton vulgaris) is our most widespread newt. The coloration is highly variable, with the back and sides being light yellow-brown to brownish-gray. During the breeding season, the male has a prominent crest that is not interrupted in the pelvic region and smoothly transitions to the tail (Fig. 14B). There is a bluish stripe on the lower side of the dorsal crest. Dark oval spots are present on the body, and similar spots are also found on the belly. Two dark stripes extend from the tip of the nose along the side of the head, with one passing through the eye (Fig 14A, B). Females are less colorful, having small dots instead of larger dark spots, which may even be absent. Dark stripes on the head are also present in females. 37 Fig. 14. Smooth newt with visible dark stripes on the head (A, B); a typical-looking male during the breeding season (B). The Carpathian newt (Lissotriton montandoni) is an endemic species to the Carpathians. It gives a square impression due to the presence of skin ridges running along the sides of the back. The back is sandy yellow, yellowish-brown to olive-green, covered with small inconspicuous spots or dots. There are no dark spots on the yellow to orange belly. During the breeding season, males have a prominent thread-like appendage at the end of the tail (Fig. 15). Fig. 15. Prominent thread-like appendage at the end of the tail in the male Carpathian newt during the breeding season. In Slovakia, two species of fire-bellied toads are found: the fire-bellied toad (Bombina bombina) and the yellow-bellied toad (Bombina variegata). Where their ranges overlap, they can interbreed. The fire-bellied toad inhabits lowlands and 38 hills up to 400 meters above sea level. The warts are bluntly rounded, giving a smoother feel to the touch. The ventral side displays a spotted pattern of red, orange, or yellow, covering a smaller area. The spots on the belly are separated from the spots on the limbs (Fig. 16D). Additionally, the spot on the palm of the front limbs does not extend into the first finger (Fig. 16C, upper image). The yellowbellied toad is more robust and is associated with forested areas at medium altitudes. The warts are more pronounced and rougher to the touch. The yellow pattern on the belly covers a larger area (over 50%), and the spots on the belly are fused, interconnected with the spots on the limbs (Fig. 16E). The spots on the palms extend into the first finger (Fig. 16C, lower image). Fig. 16. Variability in the color of the dorsal side of fire-bellied toads (A, B), palm spot not extending into the first finger in the red-bellied toad (C, top), palm spot extending into the first finger in the yellowbellied toad (C, bottom), small belly spots separated from spots on the limbs in the redbellied toad (D), large belly area covered with spots and their connection to spots on the limbs in the yellow-bellied toad (E), defensive posture in danger (F). The fire-bellied toad (Bombina bombina) primarily inhabits permanent water bodies such as ponds, oxbow lakes, blind river arms, or water reservoirs in sand pits. In contrast, the yellow-bellied toad (Bombina variegata) prefers smaller temporary water bodies, such as puddles on forest paths, marshes, waterlogged meadows, and small ponds in abandoned quarries or sand pits. The European tree frog (Hyla arborea) is an arboreal frog species adapted to a tree-dwelling lifestyle. Equipped with circular discs on the tips of its fingers, it can climb vertically even on very smooth surfaces. The skin on the dorsal side is usually green, but it can change color depending on the environment or stress (Fig. 17 A, B). Therefore, its coloration can be highly variable. A dark stripe runs along 39 the sides of the body, from the nostrils through the eye, eardrum, base of the front limbs, to the level of the hind limbs. The belly is white. Males have a prominent vocal sac, which they use to produce characteristic sounds to attract females for mating (Fig. 17 C). The European tree frog prefers open, well-lit habitats near smaller to moderately sized water bodies with rich herbaceous vegetation along the shoreline, the presence of trees, and meadow habitats. Various ponds, blind river arms, and smaller ponds are common breeding sites for this frog species. Fig. 17. European Tree Frog. A. View of the dorsal and lateral sides of the European Tree Frog, B. European Tree Frog with significantly changed color on the dorsal side of the body, C. Discs on the tips of the fingers and the vocal sac in a relaxed state. The spadefoot toad (Pelobates fuscus) is restricted to lowlands and foothills in our region, with its occurrence tied to sandy or clayey soils, or areas with loose substrates. This frog has a slit-like pupil, a triangular head with a distinctly elevated crown. There is a pronounced stiff metatarsal bump on the hind legs. The coloration varies from gray to olive-brown with irregular darker spots (Fig. 18). Red dots are sometimes present on the sides. It burrows into the substrate using its metatarsal bumps and can bury itself up to 1 meter deep during the day, enduring winter in this way. It is nocturnally active. Fig. 18. A. Spadefoot Toad rescued from a vertical shaft in a field near the village of Streda nad Bodrogom, B. individual found in Hatfe near the village of Viničky. 46 Fig. 22. Morph "striata" of the Lake Frog (A), Morph "maculata" of the Lake Frog (B) Taking into account the influence of non-selective elimination on the genetic structure of the population, as well as several features of the striata morph, it can be concluded that the high prevalence of this phenotype in polluted water is due to the advantages it receives under these conditions. The striata morph is characterized by a higher level of oxidative-reductive processes, hemoglobin content, reduced sodium permeability, and the content of certain metals at a greater body mass. The change in the phenotypic structure of amphibian populations in polluted water is associated with the different adaptive value of phenotypes, manifested in their selective mortality. Therefore, the ratio of striata and maculata phenotypes in amphibian populations can be a convenient indicator for bioindication of pollution. Morphological indicators of amphibians against anthropopressure Measurements of standard morphological parameters were conducted using a caliper with an accuracy of 0.1 mm. The sizes of morphological features are largely influenced by the surrounding environment, and the average values of many characteristics can be reliable markers of negative changes occurring in the habitat of amphibians. Living in polluted waters is usually associated with changes in the external indicators of amphibians (body length and mass). It is known that amphibians in polluted water are smaller in size. This may be due to the accumulation of toxic substances in their bodies and disturbances in metabolism. For bioindication, it is advisable to use both the entire complex of characteristics (males and females) and individual, most informative ones, as an increase in the A B 47 concentration of heavy metals in the water leads to a significant change in all morphological features. Teratogenesis in Amphibian Populations Under conditions of environmental stress, the diversity of anomaly types and the overall frequency of aberrations change, so the variety and frequency of anomalies can be an indicator of the degree of transformation of the natural environment. In our opinion, a high frequency and variety of anomaly types can be an indicator of chronic stress, caused by an increased content of heavy metals in the water. According to literature data, anomalies result from a critical disturbance of developmental stability. The frequency and variety of congenital morphological anomalies can be highly effective in environmental monitoring systems. Developmental Stability The assessment of developmental stability is conducted based on the fluctuating asymmetry indicator. The degree of water pollution compared to the norm is determined by the disruption of developmental stability based on fluctuating asymmetry. The fluctuating asymmetry indicator reflects morphogenetic homeostasis. Summary: For rapid primary bioindication of the ecological state of water bodies and rivers, it is advisable to use population characteristics of tailless amphibians, such as the ratio of males to females, the proportion of the striata morph, and the assessment of fluctuating asymmetry. For an extended, in-depth assessment of the ecological state of water bodies and rivers, the entire complex of tested population, organismic, and cytological characteristics sensitive to environmental pollutants may be recommended. This complex includes (in addition to characteristics for primary bioindication) variations of morphometric parameters, indices of internal organs, and feeding, detection of the spectrum of phenodeviants, assessment of ontogenetic homeostasis based on the level of stability of nuclear structures. High birth rates and a wide variety of phenodeviants can be recommended as indicators of water body and river pollution with heavy metals. The bioindication test system can be used in operational environmental monitoring systems and for ecological forecasting of the situation's development. 48 3.4 Amphibians - Tasks to Practice Task 1. Try to explain the concepts "amphibian and indirect development" associated with amphibians. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... Task 2. Try to write about the three orders (scientific and Slovak names) into which the class of amphibians is divided, and specify which ones occur in our territory. ............................................................. ............................................................. ............................................................. Task 3. How would you name, in one word, the process depicted in the picture? (correct answer: metamorphosis) 49 Task 4. Try to classify the amphibian eggs based on their visual assessment into the genera where they occur. Do the eggs have a calcareous shell? What are they susceptible to? ............................................................................................................................................... ............................................................................................................................................... ........................................ Task 5. With which three body organs do amphibians breathe, and in what developmental stage? 50 Task 6. Professionally name the types of fertilization and explain how they occur in our anuran and caudate amphibians. Anuran amphibians - ........................................................ ........................................................ ........................................................ Caudate amphibians - ........................................................ ........................................................ ........................................................ Task 7. All our amphibians are legally protected. What does this mean for us? ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... 51 Task 8. Amphibians are currently among the most endangered vertebrates globally. Try to reflect on the factors threatening amphibian populations today and causing the extinction of some species. Task 9. You already know the meanings of the terms oviparous and ovoviviparous. Try to classify our amphibian species into the respective categories based on their reproductive methods. Oviparous Ovoviviparous The causes of declines in populations and extinction 52 Task 10. Imagine you are in the field and come across a spotted salamander. Based on what criteria could you determine whether it's a male or female? Does this amphibian species exhibit secondary sexual characteristics that allow for a straightforward distinction between genders? If yes, you can also draw these characteristics. ............................................................................................................................................... Task 11. Among the so-called "large newts" in our fauna, we classify species of newts that have larger sizes compared to other newt species. These large newts can be distinguished by their greater dimensions. ............................................................................................................................................... Task 12. Try to match the species with their morphological descriptions. Species 1. Lissotriton vulgaris 2. Ichthyosaura alpestris 3. Triturus dobrogicus 4. Lissotriton montandoni 5. Triturus cristatus 1 2 3 4 5 53 A. This is one of our most colorful newts. Females have marbling on the upper side of the body, and the belly is orange without spots. During the breeding season, males have a low but distinct black and yellow stripe extending from the head to the tail along the back. On the lower edge of the tail, there is a bluish stripe. The body is covered with prominent dark spots, and there are two dark stripes on the side of the head, one passing through the eye. B. It is the most widespread newt in our territory. The belly is whitish to orange with dark spots. During the breeding season, males have a prominent crest on the back from the head to the tail, uninterrupted in the pelvic area. On the lower edge of the tail, there is a bluish stripe. The body shows distinct dark spots, and two dark stripes run from the tip of the nose on the side of the head. Females are less conspicuous in color, with small dots instead of larger dark spots. Dark stripes are present on the head. C. It is a Carpathian endemic species. There are no dark spots on the belly, and skin ridges extend on both sides of the back, making the cross-section of the body angular from above. During the breeding season, males have a prominent thread-like extension at the end of the tail. D. The body is brown to dark reddish-brown from above. Dark spots are present on the back and sides. The belly is brightly orange-red with dark spots. The dorsal crest in males reaches up to the eye level, interrupted in the pelvic area, and continues on the tail. Limbs are short, and when pressed longitudinally against the body, the front and hind limbs do not touch. E. The body is dark gray from above with dark black spots and small white spots on the sides. The belly is yellow to orange with dark spots. The strongly serrated crest in males starts from the head at the eye level, and on the sides of the tail, there is a pearly shiny stripe. Limbs are longer, and when pressed longitudinally, the front and hind limbs touch each other. 54 Task 12. Try to name the professionally marked bones that occur on the skeleton of frogs. Task 13. What is the name of the pigmented structure on the fingers of the front limb in frogs? In which gender does it occur and what is it for? ............................................................................................................................................... Task 14. How would you distinguish a yellow-bellied rabbit from a red-bellied rabbit? What else do we have to take into account when determining the individuals that overlap the areas of occurrence of these two species? ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... Task 15. Name and assign suitable terrestrial or aquatic environments to each species where we could find them. 55 e. B 3 5 C A D E 2 1 4 62 limbs, tail, etc.), try to classify the tadpole into the corresponding developmental stage (more information in the Study Text). Record all these observations in a table. Location Date Habitat Position of respiratory opening Deformities Gosner stage At the end, take a collective photograph of all the captured tadpoles in the Petri dish along with a scale (e.g., ruler, grid paper) from the same distance and angle. You can use a camera mounted on a tripod, with the Petri dish positioned vertically. Release all the captured tadpoles back to their capture site without causing harm. With these photographs, you will be able to work with them at school. 63 Evaluation of Field Observations in School Compare the occurrence of amphibians at the visited locations. Which species and in what numbers did you observe at each location? Consider what factors could have influenced their activity, and record your findings in a table. Location Species Number Selected Water Quality Parameters Tasks focused on the analysis of photographs: 1. By analyzing the photos you have taken, compare the developmental stages of the barnacles and possibly also the amount of deformities within the site and between sites. Study the information in the study text. 2. Measure the length of the fins from the photos taken using the Image J program. Instructions for working with Image J can be found at effuse.science.upjs.sk in the section for teachers 3. From the recorded total composition of animals at the site, determine which species could be prey or predators of tadpoles and metamorphosed (transformed) frogs. 64 Write a verbal conclusion on the species composition of amphibians at the sites: 65 4 HABITATS AS INDICATORS – subject of scientific education 4.1 Aquatic, Riparian, and Wetland Plants and Habitats as Indicators of Water Body Status Plant communities serve as crucial visual indicators of ecosystem health. Through phytosociological studies or analysis of the behavior of species forming communities, it is possible not only to assess climatic and edaphic resources but also to monitor changes in the ecosystem associated with both natural and anthropogenic factors. However, considering the difficulty of identifying communities without specialized training, it is more practical to use biotopes - the places where vegetation exists, treated as ecosystem types with spatial and temporal aspects. A biotope is a more convenient object for classification and mapping of ecosystems. The degree of representativeness and preservation of aquatic and riparian biotopes can be applied to assess the state of water bodies and conduct subsequent monitoring. The names, scope, and understanding of biotopes are based on the "National Catalog of Biotopes of Ukraine" (2018), considering regional interpretations of biotope types in other catalogs. Identification and determination of biotopes are carried out based on the presence of characteristic species, compliance with typical structure, and the specific ecological characteristics of a particular biotope, as described in the mentioned catalogs, or by using a specially developed key for determining biotope types. Criteria for Biotop Assessment In analogy to the system developed by us, considering the experience of European countries (Germany, Norway, Austria, etc.), for assessing threats and determining the conservation status of rare habitat types in the Ukrainian Carpathians and Zakarpattia lowlands, the evaluation of aquatic and riparian biotopes and surrounding vegetation as indicators of water body status should be conducted based on two main criteria: 1. Loss of area (range) where a specific biotope type is prevalent. 2. Qualitative changes in the biotope (its degradation). For the convenience and universality of assessment, it is proposed to conduct the evaluation for each criterion across three categories. 66 Criterion "Area Loss" (LA): 1 – Complete loss of area, total destruction, or very significant reduction in area – a threat of complete disappearance (today, only a small part of the original biotope area exists, or without the application of special conservation and management measures, complete disappearance may occur in the near future) – area reduction by 75-100%. 2 – Strong or substantial reduction in area (significant threat of biotope disappearance in this area; on adjacent areas, the biotope has disappeared, or there are negative trends in area reduction within the entire watercourse or locally) – area reduction by 25-75%. 3 – Absence or minor reduction in area, or remains unchanged; potentially stable – area reduction by 0-20%. Criterion "Quality Loss" (QU): 1 – Completely destroyed – the biotope has undergone such qualitative changes that typical or natural variants of the habitat are entirely destroyed, or the biotope is threatened with complete qualitative destruction (ruin) (threatened by complete destruction) or has undergone negative qualitative changes almost throughout its distribution within the watercourse, so that the typical natural structure and species composition remain only in a few or only one locality, and there is a threat of complete destruction of the biotope in a short time – qualitative changes have occurred by 75-100%. 2 – Significant qualitative changes – the biotope has undergone qualitative changes to the extent that the loss of a qualitative state covers most of the distribution within the watercourse, or the typical natural structure and species composition of the biotope have disappeared/transformed in several localities; qualitative changes have occurred by 25-75%. This point also includes biotope disturbance due to the penetration and spread of invasive species. 3 – No or minor qualitative changes, invasive species have penetrated, but they constitute a small percentage (1-5%) of the plant cover. 67 Rules of assessment Criterion Criteria for evaluating the indicator Area Loss (Area Loss – LA) 1 2 3 Well Biotope not at risk (proper functioning) Satisfactory Biotope under threat Unsatisfactory Biotope under threat of disappearance (Disrupted functioning) Absent or slight reduction in area; or remains unchanged; potentially present – reduction in area by 020% Strong or significant reduction in area (significant threat of biotope disappearance in this section, adjacent areas have lost the biotope, or there are negative trends in area reduction within the entire watercourse (watercourses) or locally) – reduction in area by 25-75% Complete loss of area, complete destruction, or very strong reduction in area – threat of complete disappearance (today, only a small part of the previous biotope areas exists, or without the application of special conservation and management measures, its complete disappearance may occur in the near future) – reduction in area by 75-100% Qualitative change of biotope (Quality Loss – QU) 1 2 3 Well Biotope not at risk (proper functioning) Satisfactory Biotope under threat Unsatisfactory Biotope under threat of disappearance (Disrupted functioning) Qualitative changes are absent or minor; invasive species have penetrated, but constitute a small Significant qualitative changes (properties) – the biotope has undergone qualitative changes to the extent that the loss of qualitative status has occurred over a large part Completely destroyed – the biotope has undergone such qualitative changes that typical or natural variants of the habitat are completely 68 percentage (1-5%) of the plant cover. of the distribution section within the watercourse, or the typical natural structure, species composition of the biotope have disappeared/transformed in several locations, qualitative changes have occurred by 25-75%; this point also includes biotope disturbance due to the penetration and spread of invasive species. destroyed, or the biotope is under the threat of complete qualitative destruction (ruin) or has undergone negative qualitative changes almost throughout the distribution section within the watercourse, so that the typical natural structure, species composition remain only in a few or only one locality, and there is a threat of complete destruction of the biotope in a short time – qualitative changes have occurred by 75100%. The assessment of the water body/stream status is carried out simultaneously using two criteria. The overall rating was calculated as the arithmetic mean of the sum of categories of the two factors. Based on the average ratings in the survey points along the watercourse, an assessment is established for the biotope within the entire distance of the watercourse. In case the average indicator falls within the range between whole numbers of categories, the indicator is always rounded up to the higher category (2-3 → 2). 69 5 SUSTAINABLE DEVELOPMENT and scientific education Activities focusing on the theme of sustainable development offer the teacher the opportunity to develop students' critical thinking skills and encourage alternative ideas and provocative questions in the classroom. The learning gains momentum and the atmosphere encourages an active approach to the issues discussed. At the same time, the underlying theme is 'playing with the unknown' for which there is no clear solution yet, which is in contrast to learning about already known facts that have already been discovered. A prerequisite for a 'fruitful' discussion or any active activity in an area that is unfamiliar to pupils is sufficient knowledge, which pupils should possess. In the framework of the EFFUSE cross-border project, this handbook has been developed for biology students, prospective teachers or practicing teachers who are interested in planning environmental education in a targeted way. In this handbook, we offer a concept for education focused on the topic of water in the context of sustainable development. The concept is designed in three modules Theoretical background, Global issues and Sustainable development. The core of education for sustainable development should be educational activities aimed at adapting to climate change, mitigating its impact and reducing its negative consequences. There is a need to emphasize greater effectiveness of education. Education reduced to rote memorization of known facts cannot bring value to society. On the contrary, creating a conducive classroom climate that encourages creativity, innovation, exploration, hands on science or alternative learning exclusively outdoors are a way to overcome the obstacles that hinder a pupil's intellectual growth. The basic knowledge needed to progress to the level of understanding global problems and designing possible solutions is covered in the first module, Theoretical Foundations. The module is divided into three thematically distinct units, Water and its "Faces", The Water Cycle and Water as the Essence of Life. After the theoretical background, the second module introduces students to more detailed Global Water Issues that are directly or indirectly related to human use of water resources. They already have some knowledge of many of them, so it is appropriate to initiate a discussion at the beginning of the module and then to adapt the content of the module. Suitable formulations of global issues might be Water as an Endangered Natural Resource and Water as a natural disaster. 70 Following the module focused on learning about the nature of global issues related to the topic of water, students move on to the most challenging part of the learning process. In the third - final module, Sustainable Development, they design solutions to problem-solving tasks, using the knowledge acquired in the previous two modules. Water Protectors, Water as a Factor in the Biodiversity of Organisms and Sustainable Project Proposals. 71 5.1 MODUL Theoretical and Practical Backround Water - Same and Always Different Activity 1: The many faces of water Objective to highlight the importance and significance of water for humans and other living organisms Time: 45 minutes Aids: papers, stationery, stopwatches Short description: The activity is an introduction to water, presenting a comprehensive view of water and its importance not only for humans, but also for life on Earth. Pupils work in groups during the activity, ideally with at least 4-5 members in each group. Procedure: The activity takes place in five rounds, alternating between a short guiding word by the teacher and student activities in groups. The teacher explains the rules of the game to the pupils. The first group sends one member to the teacher. The teacher shows him one word. The pupil's task is to use pantomime to try to show or act out the word to the other members of their group. It is important that the pupil who is showing does not say anything or make any sounds until his group has guessed it. Terms and context need to understand: water as an environment, as a necessary condition of life, as a part of our household, as a place of relaxation, as a dangerous element ROUND 1: One pupil uses pantomime to show or play the word to other members of his group, who try to guess the word. If successful, the group gets a point. In this way the groups take turns and the pupils take turns in presenting in the same way Words for the first round: river, ocean, ice, cloud 78 different volumes of the tested liquid. Lactose-peptone medium with an indicator and fermentation tubes are used as the accumulation environment. Depending on the water source, the following are investigated: • During purification and disinfection stages, 100, 10, 1, and 0.1 cm3 of water are seeded. • In tap water, three volumes of 100 cm3, three volumes of 10 cm3, and three volumes of 1 cm3 are examined. The specified volumes are introduced into bottles and vials with lactose-peptone medium with floats. Seeds of 100 and 10 cm3 of water are carried out in bottles and vials, respectively, with 10 and 1.0 cm3 of concentrated medium (for 1000 cm3 of distilled water: 100 g of peptone, 50 g of glucose, 50 g of sodium chloride, 100 cm3 of Andrade indicator). Samples of 1.0 cm3 of water are sown in vials containing 10 cm3 of normal concentration medium (for 1000 cm3 of distilled water: 10 g of peptone, 5 g of glucose, 5 g of sodium chloride, 10 cm3 of Andrade indicator). Seeds are incubated for 24 hours at 37°C. The absence of changes in the cultures allows concluding the study at this stage and giving a negative result. In the presence of cloudiness, acid, and gas in such a vial, seeding is performed on Petri dishes with Endo medium. The presence of red colonies with a metallic sheen on the Endo medium and rod-shaped gram-negative bacteria in smears, with a negative oxidase test, indicates the presence of coliform bacteria in the samples. Drinking water is considered suitable for consumption if it contains up to 100 microbial cells per 1 ml. The degree of biological contamination of water is assessed by the coliform titer and coliform index. The coliform titer is the smallest volume of water from which one coliform cell can be seeded. The coliform index is the quantity of coliform cells found in 1 liter of water. According to current standards for tap water, the coliform titer should not be less than 300, and the coliform index should be more than 3. In large cities, more stringent requirements are imposed on water quality based on bacteriological indicators: coliform index not exceeding 2, and coliform titer not less than 500. In case of bacterial contamination of water above permissible standards, additional research is conducted to detect the presence of bacteria, indicators of fresh fecal contamination, such as coliforms. Their presence is determined by their ability to ferment lactose to acid and gas at 43°C in the presence of inhibitors of foreign microorganisms (Table 2). 79 Table 2. Determination of the Coliform Bacteria Index (Coliform Index) when inoculating 333 cm³ of water: Number of Positive Results in Water Analysis Coliform Index (Coli-Index) Coliform three bottles of 100 cm³ each three vials of 10 cm³ each three vials of 1 cm³ each 0 0 0 <3 >333 0 0 1 3 333 0 1 0 3 333 1 0 0 4 250 1 0 1 7 143 1 1 0 7 143 1 1 1 11 91 1 2 0 11 91 2 0 0 9 111 2 0 1 14 72 2 1 0 15 67 2 1 1 20 50 2 2 0 21 48 2 2 1 28 36 3 0 0 23 43 3 0 1 39 26 3 0 2 64 16 3 1 0 43 23 3 1 1 75 13 3 1 2 120 8 3 2 0 93 11 3 2 1 150 7 3 2 2 210 5 3 3 0 240 4 3 3 1 460 2 3 3 2 1100 09 3 3 3 >1100 >0,9 Bacteria of the coliform group (BGC) are a key indicator when assessing bacterial contamination of drinking water, the degree of purification and disinfection of sewage, water from water supply sources, seas, and swimming pools. Some countries (such as the USA and the UK) have adopted enterococci as standards. Enterococci are part of the normal microbiota of the human intestine and are present in significant quantities in sewage. The ratio of BGC to enterococci can be used to assess the sanitary condition of water bodies. In water bodies contaminated with untreated sewage, BGC predominates over enterococci. In the 80 case of sewage disinfection, BGC dies off more rapidly, and the ratio of the number of BGC to the number of enterococci decreases almost to one. Sowing a water sample on Endo medium. Escherichia coli at 1000x magnification (Gram staining). Fig. Determination of bacteria of the coliform group on Endo medium. Activity 2: Basic measurement of water parameters Objective Observation of water parameters in the nearest water source Time: 45 minutes / work in pairs for one week Aids: Work with database Short description: Participants engage in a week-long, 45-minute activity, working in pairs to observe and record water parameters in the nearest water source. Utilizing a database, they collect valuable data to understand the quality and characteristics of the water. This activity enhances observational skills and environmental awareness by actively involving participants in monitoring and understanding local water quality, facilitated by a user-friendly database. 81 Procedure: 1. Introduction (5 mins): Emphasize the importance of water parameter monitoring. 2. Introduce the week-long task: observing and recording data from the nearest water source. 3. Database tutorial (10 mins): Briefly explain how to use the database. Specify the parameters to observe (e.g., temperature, pH). 4. Field observation (30 mins, spread over one week): Pairs regularly visit the water source, recording parameters in the database. Encourage noting any changes or anomalies. 5. Data review (5 mins): At week-end, participants analyze collected data. Discuss findings within pairs, identifying patterns. 6. For measurement of basic parameters by measurement system Vernier see Annex (page 96). Activity 3: Water as living area Objective Creation of video scenario - story for animated video focused on animals living in the water, or surroundings Time: 45 minutes / work in pairs Aids: Pen, paper Short description: During this 45-minute activity, participants will work in pairs to create a captivating video scenario centered around the theme "Water as a Living Area." The focus will be on exploring the diverse ecosystems of aquatic environments and the fascinating animals that inhabit them. Procedure: 1. Introduction (5 mins): Discuss the importance of water ecosystems and introduce the goal: creating an animated video on aquatic life. 2. Brainstorming and storyboarding (25 mins): Pairs brainstorm ideas and create a rough storyboard, emphasizing creativity in depicting water habitats and diverse animal life. 3. Scriptwriting (10 mins): Participants write a concise script focusing on engaging storytelling and educational content about the chosen aquatic environment. 4. Presentation (5 mins): Pairs present their video scenarios to the group, encouraging feedback and discussion. 82 5.2 MODUL Global Water Issues Water as an endangered natural resource Activity 1: Total water supply in the world Objective Finding out which countries have the largest reserves of drinking water Time: 10 minutes /individual work / work in pairs / work in groups Aids: internet Short description: The activity is focused on development of critical thinking and the ability to distinguish a reliable source of information. Procedure: The activity is individual work or work in pairs or groups depending on depending on the age of the pupils. The task is to find answers to the following questions: Q1. In which country is the largest supply of drinking water? Q2. Why? Q3. Is there enough drinking water in this country? Q4. Which country has the greatest shortage of drinking water? Q5. How do you think it should be resolved? Activity 2: The role of the rainforest in global weather regulation Objective Observation of water sample from lake under microscope. Time: 45 minutes / individual work Aids: Water sample, microscope Short description: Participants engage in a 45-minute individual activity exploring the crucial role of the rainforest in global weather regulation. Through observation of a water sample from a lake under a microscope, they gain insights into the microscopic life forms that contribute to the delicate balance of this ecosystem. The activity aims to foster appreciation for the intricate connections between microscopic organisms and the larger ecosystems, highlighting the essential role of rainforests in global weather regulation. 83 Procedure: 1. Introduction (5 minutes): Briefly discuss the vital role of rainforests in global weather regulation. Introduce the objective: observing a water sample from a lake under a microscope to understand the microscopic life within. 2. Sample Collection (10 minutes): Provide participants with water samples from a local lake. Emphasize the importance of sampling from a natural environment to capture diverse microscopic organisms. 4. Microscope Setup (5 minutes): Instruct participants on the proper use of microscopes. Assist in preparing the microscope slides with the collected water samples. 5. Observation (20 minutes): Participants individually observe the water samples under the microscope. Identify and note the various microscopic life forms present, such as algae, protozoa, and microorganisms. 6. Discussion (5 minutes): Conclude the activity with a brief discussion on the observed microscopic life forms. Relate the findings to the interconnectedness of microscopic organisms and their role in the rainforest's ecosystem. Water Pollution Activity 1: Water pollution Objective Be aware of the different forms of water pollution Time: 45 minutes / individual work Aids: 4 jam jars, pieces of waste, edible oil, litmus paper and vinegar Aim: to reflect on pollution in our environment, to highlight the major sources of pollution, the impacts of pollution and how to eliminate it Water is most often described as a colorless, clear, odorless and tasteless liquid. Yes, this is true if we think of tap water. But look at our streams, rivers and lakes. We can hardly think of them as colorless, transparent, odorless liquids. Supporting information for implementation: Concepts: water pollution, agriculture, industry, human settlements, transport, waste; 84 Procedure: Teacher prepares 4 samples of water pollution and labels each sample with a number: 1. cloudy water - for example, water from a river or water with soil mixed in, 2. Macro pollution - water with small pieces of waste (e.g. a piece of foil, a rusty screw, a PET bottle cap, etc.) 3. water with oil on the surface, 4. clear water with a little vinegar or citric acid. At the beginning, the teacher asks the students which of the following samples represents clear water. With further questions, the teacher asks how the pupils came to the conclusion that one sample is clean, and also initiates a discussion on the topic of what makes each sample dirty. For each sample, the teacher can ask the same questions: Q1. What is contaminating the water sample? Q2. What could have caused the contamination? Q3. How might such pollution affect life in or near the water? Q4. How can we help the water with such pollution? Step 1: The first sample of cloudy water may be natural in nature. Slightly brown colored water may contain dissolved clay particles. Green water, on the other hand, may contain algae or cyanobacteria that color it green. As an example of how water can be purified, the teacher can use filter paper to point out the purification process that treats water before it enters our homes. But who purifies water in nature? In nature, our streams, rivers and streams have a natural ability to purify, but the banks of these waters must be natural and the life in the water must be in balance with each other. And the most natural stream or river can only address its cleansing capacity up to a certain degree of pollution. Too much pollution can upset the natural balance in the water, and even completely destroy aquatic life, lakes Step 2: For the second sample, we encounter pollution that the water can't cope with the waste. In this sample, we need to highlight a problem that has become a global problem and is troubling people all over the world. Waste pollutes all our rivers, seas and oceans. Some waste heaps have grown to the size of large islands. Just type 'great pacific garbage patch' into a search engine on the Internet and look at the pictures or videos. At the same time, it is important to point out that the source of waste is us humans, our dwellings and our homes, and that waste dumped freely into the countryside is a burden that nature cannot easily cope with. The teacher can specifically draw attention to plastics, which break down in the water and break off into smaller and smaller pieces up to microscopic size, and 85 thus can enter the bodies of other animals and even humans. The solution is to clean the waters of waste and not to create unnecessary new waste (waste minimization, sorting, recycling, etc.). The teacher can gradually pick up the litter from the water and, with the help of the pupils, sort it correctly into the appropriate containers. Step 3: The third sample is water with oil on the surface. It is ideal to use dark edible oil so that the effect is clearly visible. The teacher guides the pupils to try to find an example of such pollution. Oil on water in this case simulates the behavior of oil on water in oil tanker accidents. Poisonous, dangerous substances enter the water and the oil slick itself on the surface kills many animals that come into contact with it. Getting rid of the oil slick will only solve the surface problem. Getting rid of the hazardous substances that have entered the water and that have dissolved in it remains a problem. Step 4: The last sample looks clean but contains acid, which we can prove with litmus paper. Not all contamination is visible to the naked eye. The contamination may not have any color. The amount of colorless chemicals that enter the water from industry will change the chemical composition of the water, which can have a worse impact on aquatic life than previous types of pollution. In nature, we often see a combination of these pollutions. For example, after heavy rainfall, fine soil material washes off our fields and into rivers, along with the chemicals used in farming and often the rubbish that stood in the way between the field and the river. Step 5: In the last step, the teacher will review all types of pollution, pointing out their most important sources as well as ways to eliminate them. Special attention should be paid to the waste produced by the pupils themselves, which is a serious global problem. Activity 2: Lack of drinking water Objective Creation of an article for a local newspaper on industrial activity affecting watercourses Time: 3 months / individual work Aids: Camera, video editor Short description: Participants engage in a three-month individual activity focused on creating an article for local newspapers addressing the industrial activities impacting water bodies. Utilizing a camera and video editor, they 86 document and present their findings to raise awareness about the lack of drinking water. Procedure: 1. Introduction (1 week): Present the issue of industrial impact on local water sources. Provide resources for understanding the problem. 2. Research and Documentation (4 weeks): Research local industrial activities affecting water. Use a camera to document relevant visuals and gather historical and current impact information. 3. Article Drafting (4 weeks): Draft newspaper articles, focusing on clarity, accuracy, and a compelling narrative. 4. Video Compilation (2 weeks): Compile footage using a video editor to create a visually impactful presentation. 5. Review and Editing (1 week): Review and edit articles and videos for coherence and engagement. 6. Submission (1 week): Submit final articles and videos to local newspapers and share on social media. This three-month individual project empowers participants to investigate and communicate the impact of industrial activities on local water bodies. The combination of a written article and a visually compelling video aims to raise awareness and prompt action on the issue of water scarcity. Water as Natural Disasters Activity 1: Water-related disasters of the world Objective Creation of word report about water disaster Time: 3 months / individual work Aids: Camera, video editor Short description: Participants embark on a three-month individual project to create a comprehensive word report addressing water-related disasters worldwide. Utilizing a camera and video editor, they aim to visually enhance their findings, shedding light on the critical issue of water-related disasters. Procedure: 87 1. Introduction (1 week): Introduce global water-related disasters and provide essential resources. 2. Research and Compilation (6 weeks): Conduct research on various waterrelated disasters. Compile data, statistics, and case studies for a comprehensive overview. 3. Visual Documentation (4 weeks): Use a camera to capture impactful visuals, emphasizing affected areas and rescue operations. 4. Report Drafting (6 weeks): Draft a detailed word report based on research and visual documentation. Include clear organization, informative content, and potential solutions. 5. Video Integration (2 weeks): Utilize a video editor to seamlessly integrate captured footage into the report. 6. Review and Editing (2 weeks): Review and edit the report and video compilation for coherence and accuracy. 7. Presentation (1 week): Present the report, fostering discussion on mitigation strategies and global implications. Activity 2: Regional report of water disaster Objective Creation of reginal report about water disaster Time: 3 months / individual work Aids: Camera, video editor, paper Short description: education is a critical component of disaster risk reduction and management. By educating people about water disasters, we can build more resilient communities that are better prepared to face the challenges of a changing climate. Procedure: Creating a regional report on water disasters involves several steps. Here are some general guidelines to help you get started: 1. Define the scope: Determine the region you want to focus on and the types of water disasters you want to cover. This could include floods, hurricanes, tsunamis, droughts, or other water-related hazards. You can make short videos about water disasters near your area. 2. Gather data: Collect data on past water disasters in the region, including their frequency, severity, and impact. You can find this information from government agencies, non-governmental organizations, academic institutions, and other reliable sources. 94 hammering the pegs into the ground, fixing the foil, burying the foil, carrying and feeding the pegs, etc. 2. Once the barriers are erected and the frogs begin to migrate, the second stage begins - the transfer of the frogs. These are usually organized every day (in the evening at the peak of the migration or throughout the day). 3. Once the migration is over, the barriers need to be removed so that they do not prevent the toads from getting back into the forest environment. Activity 2: Project proposal for the creation of a rain garden Objective Creation of reginal report about water disaster Time: 3 months / individual work Aids: Camera, video editor Short description: Participants undertake a three-month individual project focused on proposing and creating a rain garden to address water-related issues in their region. Utilizing a camera and video editor, they document the process and present a regional report outlining the importance of rain gardens in mitigating water disasters. Procedure: Research local rain garden success stories and case studies. Identify and visit existing rain gardens for inspiration and to understand their impact. Collaborate with local environmental organizations for expertise and potential partnerships. Find information on suitable native plants for rain gardens in the region. 1. Introduction (1 week): Introduce the concept of rain gardens and their role in water management. Provide resources on the benefits of rain gardens and their potential impact on local water-related issues. 2. Research and Site Visits (6 weeks): Research rain garden designs and best practices for the local climate and geography. Visit potential sites, documenting current water-related challenges and opportunities for rain garden implementation. 3. Proposal Development (6 weeks): Create a comprehensive proposal for the establishment of a rain garden, addressing local water disaster concerns. Include details on design, plant selection, and maintenance. 4. Implementation (8 weeks): Execute the proposed rain garden project, documenting the process with a camera. Record the stages of construction, planting, and any community involvement. 5. Video Compilation (2 weeks): Utilize a video editor to compile footage, showcasing the creation and impact of the rain garden. Ensure the video complements the detailed regional report. 95 6. Report Writing (3 weeks): Draft a regional report summarizing the rain garden project, its goals, and observed outcomes. Include data on water quality improvement and any community engagement. 7. Review and Editing (2 weeks): Review the report and video compilation for coherence, accuracy, and engagement. Make necessary edits to refine the final deliverables. 8. Presentation (1 week): Present the regional report and video to the community, emphasizing the positive impact of the rain garden on local water-related challenges. Encourage community involvement and future sustainability of the rain garden. 96 6 ANNEX How to proceed with measurements using vernier sensors If the school has a computer-supported laboratory with Vernier sensors, we can use them to measure selected chemical parameters. The Vernier measurement system offers a wide range of sensors and software programs that can be used for simple measurements in the laboratory as well as in the field. Measurement Interface Unit A small, portable device with a touch screen and intuitive control. It is used for data collection and evaluation either independently or with the option to transfer the acquired data to a computer. Equipped with a Wi-Fi system and Bluetooth interface, which allows it to connect to a variety of software programs on tablets, mobile devices, or computers. Each LabQuest package includes a charger and a USB cable for connecting it to a computer. 1 Vernier Measurement Sensors Vernier measurement sensors encompass a wide range of nearly 90 wired and wireless measurement sensors for chemistry, biology, physics, geography, technical, and environmental sciences. Each sensor package includes a storage solution with instructions for its use and potential calibration. 2 Software Equipment For more in-depth data processing (e.g., with students during lessons or in the school laboratory), a wide range of applications and programs can be used to process data from Vernier devices. The most commonly used ones are the computer program Logger Pro 3.16 (available for both Windows and Mac) and the LabQuest Viewer or Graphical Analysis applications, which are also functional on Android and iOS platforms. Fig. 1. Measurement Interface Unit LabQuest2 97 Fig. 2. Vernier pH Sensor in Storage Solution Fig. 3. Example of Sensor Connection to the Measurement Interface Unit 98 Fig. 2. Example of Connecting a Sensor to LabQuest on a Computer with LoggerPro Software. When the computer is connected to a projector, measurements or experimental analysis can be projected and discussed with students directly in the classroom. 99 Measurement procedure with measurement sensors Determination of Acidity/Alkalinity - pH Sensor (PH-BTA) The Vernier pH sensor can be used wherever traditional pH determination methods are applicable (indicators, pH strips, titration, etc.). Unlike chemical indicators that only provide a visual color change, this sensor allows for the automatic reading of the pH value of a solution and its analysis. This sensor does not require constant calibration because it comes with pre-stored calibration to respond to standard pH values in the range of 0-14 with a measurement deviation of +/- 0.02 pH (as specified by the manufacturer). Before measuring pH using the sensor, it's a good practice to measure pH traditionally as well (e.g., using indicator strips) and compare it to the value measured by the sensor. This way, you can easily determine whether the sensor needs calibration. All Vernier sensors are highly sensitive electronic devices, so it's important to follow the manufacturer's precise instructions when working with them. Tools: pH sensor, LabQuest 2 measurement unit, syringe with distilled water, paper towels Procedure: Before using the pH sensor, follow these steps: 1. Unscrew the cap from the storage bottle and carefully remove the sensor. Fig. 4. pH Sensor in the Storage Bottle 100 2. Rinse the sensor from the bottom, especially around the measuring bulb, thoroughly with distilled or deionized water from a chemical syringe. 3. Connect the sensor to the interface, and you can proceed with measuring the pH value. Fig. 5. pH Measurement 4. Submerge the sensor in the solution, wait for the value to stabilize, and read it. Only immerse the sensor in the measured solution to about the lower third of its length; there's no need to fully submerge it. 5. After reading the pH value, rinse the sensor with distilled water, pass it through the bottle's cap, and screw it into the storage solution. NOTE: If there is little solution left in the storage bottle, you can top it up with water, but not repeatedly. Over time and for longer-term storage of the sensor, it's necessary to prepare a storage buffer solution with pH 4 as instructed, which is included in the sensor package. For more information, click on this link or contact the Vernier systems supplier for Slovakia, which is PMS Delta, s. r. o., https://pmsdelta.sk/. 101 Water Hardness Detection - Conductivity Sensor (CON-BTA) The conductivity sensor can be used in the laboratory or in the field to measure the conductivity of solutions or to study the total concentration of ions. Measuring conductivity is one of the most common environmental tests for water samples. It allows us to easily detect any changes in the ionic composition of a watercourse or lake. It does not provide information about the specific types of ions in the solution but gives information about the overall level of dissolved solids (TDS). Specific ion specifications can be determined using traditional methods (e.g., titration, analytical evidence, etc.). There is an approximately linear relationship between conductivity and concentration, so, for specific ions, conductometry can be used to determine the concentration of these ions in the solution. When sampling in watercourses, it's best to take samples away from the shore and below the surface to better represent water quality. If you don't have the opportunity to measure directly in the field, you can take samples in fully filled containers (to prevent evaporation and reaction with CO2, which could lead to the creation of products that might distort the measurement). Tools: Conductivity sensor, LabQuest 2 measurement unit, syringe with distilled water, paper towels. Procedure: Before using the conductivity sensor, follow these steps: 1. Rinse the end of the sensor with distilled water. Water droplets in the measurement opening could contribute to the distortion of our measurement, so dry them by blowing or shaking the sensor in the air. Connect the sensor to LabQuest. 2. This sensor has a switch on the side for measurement ranges. This may lead to the assumption that if, for example, we expect a low concentration of ions in the measured solution, we should switch this switch to the 0-200 µS range. However, Vernier's conductivity sensor is equipped with automatic identification (auto-ID) circuits, which means when used with LabQuest data collection software, the sensor is recognized, and it configures the experiment with the most appropriate parameters. Therefore, it is not necessary to manually switch this switch. 102 3. If calibration is needed, please refer to manual for more detailed information Fig. 6. Measurement Range Switch - Use it only during calibration 4. After connecting the sensor to the interface, conductivity values will appear in the red field. By clicking in the red field, a window will open where you can select the option "Zeroing." (You can also change the measurement units here, or begin sensor calibration.) Fig. 7. LabQuest after connecting the conductivity sensor 103 Fig. 8. After zeroing - you can start the measurement 5. Insert the sensor into the sample to be measured. The oval cutout must be completely submerged in the water, and there should be no air bubbles around it. Also, do not submerge the sensor completely, including the handle, as it is not waterproof. 6. Gently stir the sample and wait for the measured value in the data collection software to stabilize. At temperatures below 15°C or above 30°C, it may take a longer time for the values to stabilize. 7. After completing the measurement, rinse the sensor with distilled water, and you can continue with the next sample (refer to step 1). Also, after finishing the measurement, rinse and dry the sensor with a towel. Always store the sensor in a dry state. For more information, click on this link or contact the Vernier systems supplier for Slovakia, which is PMS Delta, s.r.o., https://pmsdelta.sk/. 110 Procedure for measuring NO3 – concentration Tools: nitrate ISE, LabQuest 2 measurement unit, syringe with distilled water, paper towels 1) Insert the end of the ISE into the sample to be measured. It is sufficient for the electrode to be submerged in the sample just slightly above the white reference dots. You do not need to fully immerse it since the electrode handle is not waterproof either. Fig. 15. Correct submersion of the sensor into the sample Fig. 16. Incorrect immersion of NO3 - sensor into the sample (white reference points are not submerged in the solution) 111 2) Allow the ISE to rest until the measured value stabilizes, then record it. NOTE: In some measurements, especially if the sensor detects high NO3concentrations in the sample, it may take several minutes, which can negatively affect the electrode for subsequent samples. Therefore, if you have an approximate idea of the concentrations in your samples, it's a good practice to conduct measurements from the lowest concentration sample to the highest. 3) After each reading from the ISE, rinse it with distilled water and dry it before storage. For more information, click on this link or contact the Vernier systems supplier for Slovakia directly, which is the PMS Delta company, s. r. o., https://pmsdelta.sk/. 112 4 4 4 Measuring the amount of dissolved ammonium ions - ammonium ionselective electrode (ISE) (NH4-BTA) This electrode is used to measure the quantity of dissolved ammonium ions NH4+ in solution. The presence of ammonia in water is most commonly a result of field fertilization and can also occur through the decomposition of organic residues. The amount of ammonium ions in water significantly affects the pH of water samples, as there is an equilibrium relationship NH3(aq) + H+(aq) ↔ NH4 + (aq) In more acidic solutions, higher concentrations of H+ ions shift the reaction to the right, resulting in higher concentrations of ammonium ions NH4+. At higher pH values, the equilibrium shifts toward the reactants, so there will be more NH3 in the solution. At pH values lower than 7.5, essentially only ammonium ions are present in the solution. When analyzing relatively hard water, this issue does not apply, as hard water is naturally buffered against pH changes. In drinking water, the ammonium content should not exceed 0.5 mg/l, but in natural water bodies, higher values can be measured. The packaging of the ammonium ISE should contain: • Electrode with a storage bottle (with a sponge) • 30 ml bottle with a high-concentration calibration solution (100mg/l NH + as N) • 30 ml bottle with a low-concentration calibration solution (1mg/l NH + as N) • Short-term soaking bottle for the ISE Fig. 17. Ammonium ISE in the packaging 113 For accuracy and efficient measurements, it is recommended to follow a two-step preparation process for the ammonium ISE before use, similar to the nitrate electrode: 1. Soak the ISE in a high-concentration standardization solution for 30 minutes. 2. Calibrate the electrode using LabQuest. For more detailed information, please refer to this link. Collecting Data Using the Ammonium ISE Tools: ammonium ISE, LabQuest 2 measuring unit, syringe with distilled water, paper towels 1. Ensure that the sensor is correctly calibrated. If the sensor, after being connected to the LabQuest, displays a value such as 1 mg/L and is not in a solution with a concentration of 1 mg/L, you need to recalibrate it. 2. Insert the ISE's tip into the sample being tested. It is sufficient for the electrode to be slightly immersed in the sample, just above the white reference dots. There's no need to fully submerge it since the electrode handle is not waterproof. Fig. 18. The white reference dot near the electrode tip. When measuring a sample, it is sufficient to submerge the sensor just slightly above this point. 3. Allow the ISE to sit undisturbed until the measured value stabilizes, then record it. 4. After each reading with the ISE, rinse it with distilled water and dry it before storing it 114 NOTE: If you plan to store the electrode for a short time (up to 24 hours), store it in a storage bottle filled to ¾ with the high-concentration calibration solution. If you don't plan to use the sensor for an extended period (more than 24 hours), moisten the sponge at the bottom of the storage bottle for long-term storage with distilled water and screw the cap with the sensor. Fig. 19. Procedure for long-term storage of the sensor Thread the electrode through the bottle cap and seal it. Ensure that the white reference point is inside the bottle, and make sure the bottom part of the electrode does not touch the sponge, as this could damage the sensor. Fig. 20. Properly stored electrode in the storage bottle (the lower edge of the sensor does not touch the sponge, which is moistened with distilled water). For more information, click on this link or contact the Vernier systems supplier for Slovakia, which is PMS Delta, s.r.o., https://pmsdelta.sk/. 115 Measuring dissolved oxygen levels - dissolved oxygen sensor (DO-BTA) The dissolved oxygen sensor offers a wide range of tests and experiments to determine the level of dissolved oxygen as a fundamental indicator of life in aquatic environments. It can be used to monitor dissolved O2 in aquariums, detect changes in its concentration due to photosynthesis and respiration of aquatic organisms, measure oxygen consumption in waters containing organic residues where oxygen is consumed during decomposition, or establish a relationship between the amount of dissolved oxygen and water temperature. The contents of the dissolved oxygen sensor kit should include: • Dissolved oxygen sensor with a membrane cap • Calibration standard of sodium sulfite (2.0 M Na2SO3) and its safety data sheet • Electrode filling solution for dissolved oxygen sensor, a pipette, and its safety data sheet • Spare and additional components (replacement blue membrane cap, polishing strips for the sensor, calibration bottle) Fig. 21: Contents of the dissolved oxygen sensor kit 116 The dissolved oxygen sensor is delivered pre-calibrated. This calibration is sufficient for classroom use. However, for increased measurement accuracy, especially when working directly in a watercourse or lake, it's advisable to recalibrate after repeated use. You can find the calibration procedure at this link. Preparing the dissolved oxygen sensor for use 1. Sensor preparation a. Remove the blue protective cover from the end of the sensor. b. Unscrew the membrane cap at the end of the sensor. Fig. 22. Sensor after removing the electrode membrane cap c. Fill the membrane cap with 1 ml of dissolved oxygen electrode fill solution using a pipette. Fig. 23. Filling the electrode membrane cap 117 d. Carefully screw the electrode membrane cap back onto the end of the sensor. e. Place the sensor in a container with 100 ml of distilled water. 2. Sensor Activation Connect the sensor in the container with 100 ml of distilled water to the interface. Turn on the data collection program and leave the sensor like this for 10 minutes. Data Collection Using the Dissolved Oxygen Sensor Tools: Calibrated and activated dissolved oxygen sensor, LabQuest 2 data collector, syringe with distilled water, paper towels 1) Click on the red field to zero the sensor. 2) Immerse the end of the sensor into the sample to a maximum depth of 10 cm. Immersing the sensor deeper could potentially damage it. 3) Gently stir the sample around the sensor. The sensor collects oxygen from the water as it passes through its membrane, so the water around the sensor should be in constant motion. In stagnant water, dissolved O2 readings might appear to drop. 4) Wait for the reading on the display to stabilize and record it. NOTE: If you plan to reuse the sensor within 24 hours, store it in a container with distilled water (the sensor should be submerged to a depth of about 2.5 cm). However, if you won't be using the sensor for an extended period, disassemble the membrane cap and rinse the inside and outside with distilled water. Briefly dry it in the open air, gently pat the internal parts of the electrode with a paper towel, and screw the cap back onto the electrode body. For more information, click on this link or contact the Vernier systems supplier for Slovakia directly, which is PMS Delta, s.r.o. at https://pmsdelta.sk/ EFFUSE – Scientific education for advanced Educational text Authors: Publisher: RNDr. Ivana Slepáková, PhD., RNDr. Monika Balogová, PhD., RNDr. Natália Pipová, PhD., doc. RNDr. Andrej Mock, PhD., RNDr. Peter Ľuptáčik, PhD., RNDr. Mariana Kolesárová, PhD., RNDr. Lenka Maliničová, PhD., prof. RNDr. Martin Bačkor, DrSc., doc. RNDr. Yaroslava Hasynets, PhD., doc. RNDr. Vladyslav Mirutenko. PhD, doc. RNDr. Roman Kish, PhD., doc. RNDr. Mykhailo Vakerych, PhD., prof. RNDr. Maryna Kryvtsova, Dr.Sc., doc. RNDr. Fedir Kurtyak, PhD., doc. RNDr. Alexander Mateleshko, PhD., RNDr. Andrea Ivanová Pavol Jozef Šafárik University in Košice ŠafárikPress Publishing 119 7,61 Year: Pages: Author´s sheets: Edition: first DOI: https://doi.org/10.33542/EFF-0448-4 ISBN 978-80-574-0448-4 (e-publication) 2025 ISBN 978-80-8152-000-0