Fast current marginal area of the source of the Neva River, Leningrad Region, Russia

_ place in Biotope Aquarium Design Contest 2019

Volume: 540 L
Dimensions: 150x60x60 cm
List of fishes: Leuciscus leuciscus, Rutilus rutilus, Leuciscus idus, Squalius cephalus, Gobio gobio, Abramis brama
List of plants: Potamogeton perfoliatus, Ceratophyllum demersum, Chara fragilis
Description of decorations: All aquarium decorations were collected on the river bank or in the coastal forest (driftwood). Sand and small pebbles were washed to a state of perfect cleanliness. Large stones were machined. The driftwood before being immersed in the aquarium was cleaned of bark and putrid areas, dried for 4 months, and then soaked in water for half a year. Sand in the aquarium is light yellow, with a predominance of silicon, quartz and granite. Cobblestones, small and large pebbles are mainly dark gray. Driftwood are the roots of a dead willow, uprooted several years before the creation of the project by the waves and strong winds characteristic of Lake Ladoga.
Description of equipment: External filter JBL Cristalprofi e1902, compressor Eheim air pump 400, flow pump Aquael Reef circulator 6000 l / h. 2 LED spotlights 30 W, 6700 K.
Water parameters: Temperature is 20-21 ºС, pH 7.3, GH 8, NH3 0, NO2 0, NO3 0-5.
Additional info: In the aquarium there is a driftwood area in the coastal zone of the source of the Neva River. According to the legend of the aquarium, similar to the natural situation, all the elements of the trees were covered with ice-freezing on an irresistible section of the bottom landscape. In the summer, vegetation began to sprout from under it in areas accessible to light, and fry of fish settled in search of food and shelters. That is why, the vegetation in the aquarium is planted in a similar way (without changing the anatomy of the roots), and all fish are small in size. Water changes in the aquarium are carried out weekly in 40-50% of the total. Feeding takes place 2 times a day, mainly with special food, in order to avoid the entry of infectious and invasive pathogens into the aquarium. At the time of recording photo and video materials, the fish have minor damage to the surface of the body and fins. These injuries appeared during the fishing and transportation of aquatic organisms. Before putting into the aquarium, all fish went through a set of quarantine measures. At the current time, all the damage has passed, proof of this is the video shot a week after the photo session [1]. As growth, lack of biological and mechanical filtration, or due to traumatic situations, residents will either be put in other tanks or returned to their natural habitat.

INFORMATION ABOUT BIOTOPE

Description of the area surrounding the biotope: The Neva, which is part of the system of watercourses and reservoirs in the Baltic Basin District, flows from Lake Ladoga and flows into the Neva Bay of the Gulf of Finland of the Baltic Sea. Taking into account the Ladoga Lake basin, but excluding the water bodies of the Onega Lake basin, the drainage area of ​​the Neva basin is 281 thousand km² with a river length of only 74 km. The area of ​​the Neva’s own basin is 5.18 thousand km², which is about 2% of the total basin. 5 out of 12 months of the year the river is under the ice. Spring and summer floods are not significant. However, there is a tendency in the annual fluctuation of the water level [2]. The average speed of the Neva water is about 0.8-1.1 meters per second. The prevailing depth is 8–11 m; the largest (24 m) is on the right bank opposite Arsenalnaya St. Petersburg., the smallest (4.0–4.5 m) is in the Ivanovo rapids (Leningrad region). The greatest width is 1200 m (in the delta), the smallest is 210 m (at the Ivanovo rapids opposite Cape Svyatki), the average is 400–700 m. 26 tributaries flow into N. (the main are Mga, Tosna, Okhta, Izhora, Slavyanka, Chernaya, Chernaya Rechka, Utka). It has the sixth place among European rivers [3], [4] in terms of water availability (annual water discharge is 79.7 cubic km, 2530 cubic m/s). Since the approximate age of the river is about 1.5-3 thousand years and it originates from a glacial, mainly oligotrophic lake, the area surrounding it is a plain covered with sand, pebbles and rounded cobblestones at the edge of the coastal zone. Along the river bank to the city of St. Petersburg, there are secondary forests represented directly on the coastline by deciduous trees and shrubs (willow, birch, rowan, aspen, etc.). Elements of these trees, along with freezing, periodically lathers over shallow stones and other parts of the landscape on the bottom of shallow water, forming shelters for many species of fish in the early stages of ontogenesis [5].

Description of the underwater landscape of the biotope: The bottom of the river in the coastal zone at the source is gentle, without any significant changes in the landscape. There are accumulations of massive cobblestones left offshore after cleaning and widening the fairway. Soil, as a rule, is a sandy mixture of various rocks mainly of dark gray, grayish-red, light beige and other shades. Large cobblestones are also available in small quantities. Due to the strong flow of the river, most of the stones are rounded. Dendrite is found in small amounts in areas with the lowest flow rate. On coastal shallow areas up to 1.5-2 m deep, there are extensive thickets of higher aquatic plants mixed with elements of trees. Which serve both as a substrate for spawning of phytophilic fish species, and as a place of concentration of food objects and shelters for juveniles [5].

Description of the parameters of the habitat: Neva’s water is fresh (average mineralization is 61.3 mg/l), hydrocarbonate class, soft, characterized by constant and high oxygen saturation due to good aeration of the water masses with frequent and strong waves on Ladoga and other lakes. The turbidity is average. The average annual water temperature is 6.9°C, but in August the average monthly temperature is 17.4°C and sometimes reaches 25°C. Of the most important parameters for the existence of fish, it is worth highlighting: pH is 6.8-7.7, TDS is 225-270, depending on the season of the year, the river section, and abiotic factors [3], [4].

List of fishes and invertebrates occurring in the nature biotope: Since the Neva is a large river connecting Lake Ladoga and the Gulf of Finland, it is logical to assume that its ichthyofauna for the most part intersects with these reservoirs. However, this assumption is true only partly. The species composition of the ichthyofauna of the Gulf of Finland, tentatively, includes 75 species from 32 families. Some of them relate to spawning fish in sea water, so if they can be in the upper reaches of the river, it is only by an absurd accident or under the influence of man. Passing and semi-passing fish, with the exception of Salmo salar and Coregonus albula, etc., also, as a rule, do not reach Shlisselburg or are kept far from the coast. Therefore, in the framework of a specific work, it makes sense to consider exclusively the types of freshwater complex found throughout the Neva River. A similar approach is applicable to the assessment of the ichthyofauna of Lake Ladoga. At the current moment of time, abstracting from the history of the formation of both the lake itself and its fish population, according to literary sources, 43 indigenous species of fish and cyclostomes are found in the lake. For a more correct presentation, these fish species are appropriate to divide into cold-water (fish that originally inhabited Ladoga before the Neva River appeared) and warm-water (settled in the lake shortly before or after its formation). Cold-water fish species include: Lampetra fluviatilis (L.) and L. planeri (Bloch), Salmo salar m. sesebago Girard, S. trutta m. lacustris L., Salvelinus lepechini (Gmelin), Coregonus lavaretus lavaretus L., C. albula L., Thymallus thymallus (L.), Osmerus eperlanus (L.), Lota lota (L.), Triglopsis quadricornis lönnbergi Berg. Almost all of these species, with the exception of C. albula, Thymallus thymallus and S. trutta m. lacustris, either do not enter the river or are not found on its coastal areas due to the biological characteristics and needs of the species. Significant warming created favorable conditions for the appearance of warm-water fish in Ladoga, which made up the second wave of invaders. The lake and reservoirs of its private catchment were replenished with 15 species new for the region, including Leuciscus cephalus (L.), Scardinius erythrophthalmus (L.), Aspius aspius (L.), Leucaspius delineatus (L.), Tinca tinca (L.), Blicca bjorkna (L.), Abramis sapa (L.), Abramis ballerus (L.), Vimba vimba (L.), Pelecus cultratus (L.), Carassius carassius (L.), Silurus glanis (L.), Sander lucioperca (L.), etc. Thus, the composition of the fish population of the river itself is reduced to:
1. Esox lucius Linnaeus, 1758.
2. Rutilus rutilus (Linnaeus, 1758).
3. Leuciscus leuciscus (Linnaeus, 1758)
4. Squalius cephalus.
5. Leuciscus idus (Linnaeus, 1758)
6. Phoxinus phoxinus (Linnaeus, 1758)
7. Scardinius erythrophtalmus (Linnaeus, 1758)
8. Aspius aspius (Linnaeus, 1758)
9. Tinca tinca (Linnaeus, 1758)
10. Gobio gobio (Linnaeus 1758
11. Alburnus alburnus (Linnaeus, 1758).
12. Blicca bjoerkna (Linnaeus, 1758)
13. Abramis brama (Linnaeus, 1758)
14. Abramis ballerus (Linnaeus, 1758)
15. Vimba vimba (Linnaeus, 1758)
16. Pelecus cultratus (Linnaeus, 1758).
17. Carrasius carassius (Linnaeus, 1758).
18. Carassius gibelio (Bloch. 1752).
19. Cobitis taenia (Linnaeus, 1758)
20. Siluris glanis (Linnaeus, 1758).
21. Lota lota (Linnaeus, 1758)
22. Pungitius pungitius (Linnaeus, 1758).
23. Gasterosteus aculeatus (Linnaeus, 1758).
24. Sander lucioperca
25. Perca fluviatilis (Linnaeus, 1758)
26. Gymnocephalus cernua (Linnaeus, 1758)
27. Thymallus thymallus
28. Cottus gobio Linnaeus, 1758.

List of plants found in the nature biotope: Regarding the plant world of the source of the Neva, it is difficult to give a correct description due to the low qualifications of the author in this area and the lack of correct literature data. However, from personal observations, the nucleus of the phytocenosis can be clearly distinguished. It is predominantly represented by various species of charadriiformes and hornwort, among which Potamogeton perfoliatus and Ceratophyllum demersum prevail, respectively. Chara fragilis is found, forming large area clusters in areas with a moderate course. A tendency has been noticed that in areas of the coastal zone where currents are strong (similar to those are in the aquarium), Potamogeton perfoliatus prevail, and Ceratophyllum demersum and Chara fragilis are depressed, and vice versa, where current is weak because of the bottom relief, Ceratophyllum demersum and Chara fragilis prevail [5].

Threats to the ecology: Roshydromet characterizes the Neva as “polluted” and “very polluted”. The river belongs to the third pollution class, the maximum is the fifth. With the fifth class of pollution in water bodies, most organisms are no longer able to survive [9]. The main polluter of St. Petersburg waters is the state unitary enterprise Vodokanal of St. Petersburg. According to the city Committee for Nature Management, it is this enterprise that accounts for most of the damage from the discharge of pollutants into the water bodies of St. Petersburg. This is not surprising, since the main volume of wastewater does not enter the water directly, but through the city sewage system. That is, both household discharges and toxic waste from enterprises fall into one pipe, and then this mixture is either discharged directly into rivers, or goes to urban wastewater treatment plants [9]. In 2007, Greenpeace investigated the toxicity of Neva fish. It turned out that it contains polychlorinated biphenyls. In such concentrations that in Europe this fish would be banned for sale immediately. Because PCB is one of the 12 most dangerous persistent organic pollutants and can cause cancer. In addition to PCBs, arsenic was found in Neva fish, also in very high concentrations. Chronic poisoning with this substance leads to loss of appetite and weight loss, gastrointestinal upsets, peripheral neurosis and skin melanoma, which often turns into cancer [9]. In addition to environmental factors, most of the fish species living in the river are under pressure from fishing, sport and recreational fishing, and poaching. Living personally on the river bank in person, I have repeatedly noticed, in the catches of “lovers-poachers”, fish species included in the Red Book of the Leningrad Region. These include Thymallus thymallus. In addition, many sections of the river suitable for spawning are covered with nets (the Chernaya River, Popova Ditch), which also has a negative effect and can contribute to the destruction of even commercial fish species [5].

Sources of information:
1) Video with healthy fish: https://vk.com/video?z=video26495913_456239468%2Fpl_cat_updates
2) Explanatory note to the consolidated volume of standards of permissible impact on private exposure p. Neva (from source to mouth). Ed. Ministry of Natural Resources and Ecology of the Russian Federation. Book 2. Page 35.
3) Articles / Neva: http://www.encspb.ru/object/2806260523?dv=2853966463&lc=ru
4) Neva: https://ru.wikipedia.org/wiki/%D0%9D%D0%B5%D0%B2%D0%B0
5) The source of the Neva River, from the perspective of creating a biotope aquarium #BADC2019 / AUTHOR’S PHOTOS AND VIDEO: https://vk.com/@pesokikorni-istok-reki-nevy-s-pozicii-sozdaniya-biotopnogo-akvariuma-bad
6) S.V. Kolesnik. “Ladoga lake”. Hydrometeoisdat. 1968.: http://ladoga-lake.ru/pages/artcl-ladoga-kalesnik-23.php
7) Kudersky L. A. Natural resource potential and water use of Lake Ladoga. Bioresources and fishing. Electronic resource. Pages 363-397.
8) Chernova I.V. A brief review of the ichthyofauna of the Vyborg Bay. Marine biology. Electronic resource. Pages 56-64.
9) The state of the Neva. Greenpeace: http://www.greenpeace.org/russia/ru/campaigns/water-pollution/saveneva/condition/

Comments of the members of the jury of Biotope Aquarium Design Contest 2019