THEORETICAL FOUNDATIONS OF FISH FARMING - I.M. Sherman - 2011

1. THEORETICAL FOUNDATIONS OF THE FORMATION AND UTILIZATION OF BIOPRODUCTIVITY IN VARIOUS TYPES OF WATER BODIES

1.1. Theoretical aspects of the generation, transformation, and utilization of food resources in fishery water bodies

The bioproductivity of Water bodies and their bioproduction potential share a common theoretical foundation, yet The formation of these bases exhibits distinct specificities across various types of aquatic ecosystems.

As stated above, primary organic matter is produced through Photosynthesis, which accounts for the lion's share of primary organic matter on a planetary scale.

Based on their role in organic matter synthesis, green plants are collectively termed producers, including those in aquatic environments. During photosynthesis, green plants produce and release oxygen into the surrounding environment, which enters the atmosphere and saturates water in dissolved form. This enables the Respiration of aquatic organisms that do not utilize atmospheric air and lack Lungs, with fish respiration being sustained by gills combined with a corresponding general system.

Aquatic ecosystems are inhabited by diverse PLANT AND ANIMAL organisms with varying population densities and biomasses due to numerous influencing factors. Based on these characteristics, they are divided into two main groups: producers—plant-origin organisms capable, under certain conditions, of synthesizing organic matter from inorganic precursors; and consumers—animal-origin organisms utterly incapable of synthesizing organic matter from Inorganic Compounds under any circumstances, which instead consume pre-existing organic matter of plant, animal, or mixed origin.

Thus, it is evident that the bioproductivity of water bodies is formed by producers and consumers represented by specific species with corresponding Abundance and biomass.

Unlike producers, consumers are categorized into specific orders whose definition is based on and dependent upon the objectively existing distance between consumers and producers.

The entire aggregate of producers and consumers—all living matter within hydroecosystems—constitutes its bioproduction potential. Certain distinctions exist between the bioproduction potential and food resources in fishery water bodies of various origins and purposes. Bioproduction potential encompasses all hydrobionts of a given water area, whereas food resources represent that subset of the bioproduction potential composed of forage hydrobionts.

In natural fishery water bodies—such as oceans, seas, river systems, lakes, estuaries, and bays—food resources are generally subject to minimal human impact; however, the smaller the water body, the more pronounced human activity becomes, and vice versa.

Artificial water bodies—namely classical fish-farming ponds, small and medium reservoirs of various purposes and origins—have been transformed and possess their own specific characteristics. The primary feature of these artificial water bodies is their non-natural hydrological regime, characterized by water level fluctuations, periodic draining, and refilling driven by seasonal components and technological requirements tied to their intended use.

A special position within this context is occupied by natural fishery water bodies that have been significantly altered by human activity, predominantly hydrotechnical construction. In some cases, this has led to an increase, and in others to a decrease, in food resources. At the same time, specific trends emerge, driven by the operational Features of water users and their corresponding technologies.

Considering the above, it must be emphasized that while general patterns govern the generation, transformation, and utilization of food resources in fishery water bodies, they inherently possess distinct specificities. In this regard, it is appropriate to re-emphasize that food resources constitute a component of the bioproduction potential, represented by producers and consumers across various trophic levels.

By examining the flora and fauna of fishery water bodies, one develops an understanding of the species composition of respective hydrobiont groups, their abundance and biomass, and the alignment between the species COMPOSITION OF THE ichthyocoenosis and the composition of forage hydrobionts, thereby determining the potential consumption volumes of specific forage organisms. Following this theoretical approach to resolving this rather complex issue and performing relevant practical calculations, a realistic opportunity arises to objectively determine food resources based on specific groups of hydrobionts.

Building upon the regularities of organic matter formation, it is essential to account for the dynamic nature of this process and the pathways leading to food resources in exploited fishery water bodies. Simultaneously, one must recognize that a resource, regardless of its formation specifics, cannot be an end in itself. The ultimate component that directly determines the fishery Prospects of exploiting a specific water body is the food Base of the respective fish species.

In this regard, bioproductivity as a problem of the expanded reproduction of valuable aquatic products should be viewed as a leading yet summarizing link in the progression from bioproductivity through food resources to the food base. Reaching the food base in natural and transformed natural water bodies enables the formation of an optimized ichthyocoenosis through regulated fishing utilizing selective gear and environmental improvements.

The process of managing The Development of forage hydrobionts must, in turn, be accompanied by appropriate ameliorative measures

aimed at maintaining water quality at a level that fully complies with the biological requirements of cultivated fish species.

Naturally, oceans, seas, bays, estuaries, lakes, and river systems—being natural water bodies—cannot be subjects for applying Traditional Methods of enhancing the bioproductivity of fishery environments. Large, transformed natural water bodies may also be included among these, for which ameliorative works in appropriate volumes are more desirable and necessary to create suitable conditions for naturally and artificially formed ichthyocoenoses.

Summarizing the above, it is appropriate to focus on methods for managing the bioproductivity of fishery water bodies. It must be stressed that the vast majority of fishery water bodies, regardless of origin and purpose, are utilized by multiple water users, which necessitates a balanced approach taking into account the interests of all stakeholders.

Based on the proposed concept, intensity-boosting measures capable of polluting water must be excluded for all natural, transformed, and artificial water bodies with long-term water discharge regulation. Comprehensive intensification is permissible exclusively in specialized classical fish-farming ponds, ideally subject to approval by sanitary and veterinary authorities. For all fishery water bodies without exception, bioproduction management is possible under conditions of Coordinated regulation of water content and trophicity through regulated fishing concerning timing, quotas, and fishing gear.

Bioproduction potential, bioproductivity, and food resources are represented in water bodies by corresponding groups of forage hydrobionts. Producers are represented by flora, essentially comprising phytoplankton and macrophytes. Consumers are represented by fauna, primarily consisting of zooplankton and zoobenthos.

Floristic complexes produce primary organic matter via photosynthesis, while faunistic complexes consume pre-existing plant organic matter either directly or indirectly. This process is dynamic, exhibiting consistent seasonal patterns and zonal specificities linked to soil and climatic zones.

The functioning of producers and consumers is closely interrelated and serves as a vital component reflecting the transformation of matter and energy within water bodies. Of particular interest in this regard is the utilization of generated matter and energy by respective producers and consumers across various trophic levels.

To address this crucial theoretical question, numerous experiments were conducted, leading to a major concept that profoundly influences the solution of contemporary problems in practical fish farming.

Producers, represented by phytoplankton and macrophytes, generate primary organic matter through photosynthesis and serve as the primary source of organic products in modern aquatic ecosystems. To transfer this primary product in nature, a transformation mechanism operates, providing nourishment for various animal species.

The energy generated by producers and utilized by consumers has varying efficiency coefficients, which depend directly on the consumer's trophic distance from the producer. Accordingly, optimal utilization of primary organic matter is observed in animal species whose diet largely consists of phytoplankton and macrophytes, which in turn serve as food for consumers at higher trophic levels.

From the theoretical perspective of these transformation processes, energy losses are minimized when primary producers are consumed directly by herbivorous fish. Extending the food chain inevitably leads to increased energy losses, reduced productive efficiency, and, consequently, lower fish yields.

Under real-world conditions, a specialist who applies existing methods and sound theoretical knowledge can actively influence the rational use of food resources to enhance bio-production, ultimately increasing the productivity of fish ponds and other fishery water bodies.

Food resources naturally exist in aquatic ecosystems of diverse origins and purposes. While the Qualitative and quantitative aspects of these resources have their own specific characteristics, the management and intervention methods applied to them also possess unique features.

During the growing season, the water bodies of classical commercial fish farms—specifically summer-use ponds—can be appropriately managed through comprehensive reclamation measures tailored to specific requirements and the application of fertilizers.

Numerous theoretical studies and the practical experience of various ownership-form enterprises convincingly demonstrate the feasibility of significantly increasing the abundance and biomass of hydrobionts that constitute the food base. This can be achieved through timely reclamation work combined with the well-founded, rational application of organic and mineral fertilizers under close laboratory supervision.

Any newly created food resource must be linked to consumers capable of transforming this resource into the feeding base for valuable fish species—the desired targets of cultivation.

Building upon the proposed concept, a clear picture emerges of an interdependent dual process: food resources comprising specific quantities and biomass of certain food hydrobionts, and consumers represented by artificial ichthyocoenosis components that effectively transform these resources into a feeding base and accumulate high-quality fish biomass. A promising approach to managing the dynamics, abundance, biomass, and utilization of food resources in pond fish farming is the specialized cultivation of targeted hydrobionts to feed specific fish species directly. Depending on the feeding habits of the cultivated fish, live feeds are grown in specially controlled environments. These feeds serve, on the one hand, as physiologically complete Nutrition and, on the other hand, actively influence the species composition, abundance, and biomass of the natural food hydrobionts inhabiting artificial pond ecosystems.

For natural and modified water bodies, the principles of effective management and utilization of food resources focus on achieving an optimal balance between producers and consumers across various trophic levels. In such environments, active and direct intervention in food resources is rather problematic and nearly impractical. Nevertheless, by regulating commercial fishing and employing selective gear, it is possible to effectively influence the abundance of species that form the commercial ichthyofauna. In some cases, native ichthyofauna may also include re-acclimatized or acclimatized species, which requires appropriate scientific justification.

When conducting fishing operations in natural and modified water bodies, it is essential to comply with fisheries regulations, preserve the species composition of the aquatic ichthyofauna, and pay special attention to the conservation of rare and endangered fish species.