eChapters

Temperature is the measure of the thermal state of a body with respect to its ability to transfer heat. Soil derives its heat almost entirely directly from the sun and losses much of it back into the atmosphere. The major processes for heat transfer in soil are: Radiation, Convection, Conduction and Latent heat exchanges between soil and atmosphere. The most important source of which is the incident radiation supplying almost all the heat energy for the biosphere and also determines the thermal regime of soil. Soil temperature or thermal regimes of soil is an extremely important property of soil as it regulates plant growth directly and influences moisture and aeration status in soil, soil structures, microbial activities and decomposition of plant residues and the availability of plant nutrients . It is controlled mainly by its thermal properties and radiation exchange over the surface and their variations within the soil. The quantity of incident solar radiation and heating the soil depends on the several factors such as exposure and latitude, albedo, soil colour, slope vegetation and composition of soil.

Water is absolute necessary constituents for the survival and growth of all the living substances on earth. It is the most essential ingredients for many of the physiological and metabolic process in plants, like photosynthesis to form sugars, translocation of cell constituents and maintenance of cell turgidity. Soil, being an adsorbent of water received from precipitation or rainfall acts as reservoir to meet requirement by plant during growing season. Water retained in the soil serves as solvent to dissolve salts and nutrients and as a carrier to translocate them for absorption by plants. It plays significant role in weathering reaction, soil forming processes and profile development. Water is also important for growth and activities of microorganisms influencing decomposition of organic matter, transformation of mineral nutrients and other physical, chemical and biological properties in soil. This chapter deals with the retention and movement of water in soils to obtain better understanding of soil-water-plant-atmosphere relationships.

The major components of soil consisting with mineral and organic matter, water and air produces a three phase systems of solid, liquid and gas. Many of the soil properties influencing crop growth and other uses depend mostly on the relative proportions of these components as well as the size, shape and arrangements of the solid matters. The physical properties of soil have strong significance in sustaining agricultural productivity. Fertiliser alone or in conjunction with suitable crop varieties and plant protection measures cannot be sufficient towards improving crop productivity unless the soil physical properties are maintained at satisfactory level. Improvement and restoration of physical properties in soil are necessary for protection of soil resources against degradation. The physical properties of soil discussed in this chapter includes soil densities, texture, structure, porosity and consistency of soils and colour of the soil.

Soil Colloids A colloid, also known as colloidal solution or colloidal system, is a mixture in which finely divided particles (less than 1µm in size) known as dispersed phase are suspended in a medium, called dispersion medium. The particles must be dispersed in a medium and both the dispersed phase and dispersion medium may be solid, liquid or gaseous which leads to numbers of possible colloidal systems. In soil, the clay fraction (< 2µm in size) together with finer fractions of some organic matter forms the composition in a state of colloidal nature, known as soil colloids. The soil solids as dispersed phase predominates in the dispersion medium (soil solution). As such, colloids in a soil are referred to as ‘sol’. Clay colloids display the most reactive fractions of soil governing their distinct properties such as adsorption and exchange of ions, zeta potential, flocculation and other electrokinetic phenomenon.

The organic constituents of soils or soil organic matter is the most essential components of soil consisting of plant and animal residues at various stages of decomposition, cells and tissues of living or nonliving organisms and the substances synthesized by their decomposition. Soil organic matter exerts profound effect on soil productivity as it acts as source and sink of plant nutrients especially nitrogen and sulphur. It also involves in major biochemical processes to transform or release of plant nutrients into their available forms. Thus, it plays vital role in soil fertility maintenance, through increasing cation exchange capacity and improving soil physical properties, such as bulk density, aggregation, water retention capacity and also supports all kinds of biological activities in soil. The soil organic matter mostly concerns only with dead organic fractions formed from the decomposition of original plant and animal residues using as a source of food and energy by the soil microorganisms. It can be distinguished into –

Soil is a dynamic natural body of the uppermost layer of earth’s crust produced by the transformation of mineral and organic substances on the earth’ s surface under the influence of environmental factors over a long period. It is the most basic of all natural resources upon which all living forms on the terrestrial ecosystem directly and indirectly depends. However, soil resources are finite, nonrenewable, fragile and heterogeneous in space and time. As a component of pedosphere, it occurs as interface between the lithosphere and atmosphere and strongly interacts with biosphere and hydrosphere (Figure 1 & 2).

Soil is a natural resource that exists on the planet much before the existence of mankind on it. The human relationship with soil throughout the history of mankind has marked its ability of crop production and influenced the success of civilisation. Such relationships also affirm soil as the foundation of agriculture and food security, supplying all the essential ingredients to plants, as fundamentals to life on planet, and support various biogeochemical cycles on earth’ s terrestrial ecosystem. Prosperity of human society depends on the utilisation of planet’ s resources in creative and productive ways. Of these resources, soil has gained much importance as it provides human to sustain themselves with their capacity to food production, to make significant contribution towards biodiversity and other ecosystem services that are vital for the functioning and resilience of earth’ s environment. Soil occupies a pivotal position in the environment to maintain its quality.

Introduction Rapid increase in world population in last few decades has challenged the food producing sector (Agriculture, poultry, dairying and aquaculture) massively to meet the global food demand. The population is expected to be 9.9 billion by 2050 which means the food producing sector have to increase production by 60% further more than the current production (FAO, 2020). According to FAO (2016) approximately 17% animal protein and 7% total protein consumed by humans were provided by fish. Accordingly, per capita fish consumption was gradually increasing worldwide at 1.5% rate annually from 9.0 kg in 1961 to 20.5 kg in 2017 (FAO, 2018; Fajardo et al., 2022). Aquaculture which accounts for 47% of total fish production is expected to overtake capture fisheries by 2024 and reach 52% by 2029 (FAO, 2020).

Introduction “Xenobiotics” are “foreign compounds,” which are alien to the organism and removed from their natural environment. Xenobiotics are substances that are either alien to an organism or do not form a natural part of its diet. Compounds including pharmaceuticals, food additives, & environmental toxins are examples of xenobiotics. Normally, these substances are removed from the body by being broken down into compounds and then being expelled through the kidney, bile and lungs. For the pharmaceutical business, enzymes that metabolize xenobiotics are crucial because they are in charge of breaking down medicines. Similarly, xenobiotic transporters influence how long medications remain in the body.

Introduction Feed is a major source of nutrition in semi-intensive and intensive culture systems. Fish fed with formulated feed is used for their growth, maintenance, and reproduction. Feed Energy utilized for maintenance is mainly for health and survivability. In intensive aquaculture, animals almost exclusively depend on an external supply of high protein feed (generally >20%), usually based on fishmeal (Beveridge and Little, 2002) because of its high protein content, better bioavailability of amino acids, palatability, and unknown growth factors. Hence fish fed with a fish meal-based diet exhibits better growth performance, feed conversion, and fish health than fish fed with other animal and plant-based protein sources (Hardy and Tacon, 2002; Pike and Barlow, 2002; Tacon, 2003; Cook et al., 1996). Still, Global fish meal production is annually decreasing since 1994 due to increased human utilization and increased use of fish residues and by-products, increasingly replacing whole fish for fish meal (FAO, 2020). Hence many scientists were passionate about replacing the fish meal with an alternative feed ingredient without compromising growth.

Introduction The ecological stability and food web of intertidal environments are significantly influenced by macroalgae. The majority of marine organisms, including macroalgae, coral reefs, sponges, and the organisms that they are associated with, are well known for producing secondary metabolites and bioactive compounds, which increase their value in a variety of industries, including food, neutraceuticals, pharmaceuticals, and others. Among them, seaweeds play a vital role in promoting health by offering a variety of phytochemicals with antioxidant, antibacterial, anticancer, and antiviral action (Ngo et al. 2012). Worldwide, there have been more than 20,000 macroalgal species identified. In South Asian nations including China, Japan, and Korea, it has been used as sea vegetables. India now has 841 macroalgal species identified,including 434, 191, and 216 species of red algae, brown algae, and green algae, respectively (Oza and Zaidi, 2001).

Introduction Fish oil is the major source of essential Fatty acids (EFA) for humans. Generally, Fish requires three long-chain highly unsaturated Fatty acids (HUFA) for their normal growth and development including reproduction like docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6) (Sargent et al. 1993a, 1995, 1997). Like the terrestrial mammals, DHA, EPA, and ARA are all involved in maintaining the cell membrane structure and function of fish but majorly EPA and DHA are considered. Moreover, the EPA and DHA are the major currency as fatty acid for the synthesis of phospholipids, Prostaglandins, and energy etc. However, the biosynthesis of EFA in fish changes in accordance with the relative bioconversion capacity of the PUFA (Linoleic acid and α-Linolenic acid) as shown in figure 01.

Introduction A genome marker or a genetic marker is words commonly used to refer to a marker, which is identical to the term “marker.” Genes, genetic variants, or random sequences can all be represented by markers. Markers act as milestones or signposts while creating DNA and genomic maps. Markers are DNA sequences that are frequently identified by their position in a genome. The transmission of traits or the risk of sickness within families can be tracked using markers. It is essential to the continued existence of the species and boosts an organism’s ability to adjust environmental conditions. In conjunction with other evolutionary forces like genetic drift and selection, genetic diversity inside an individual evolves, leading to divergence at the population/ communities, species, as well as higher order taxonomic levels (Askari et al., 2013). Numerous fields, including evolutionary research, resources management and conservation, and genomic improvement programmes, can benefit from the conclusion derived from genetic variety data (Liu and Cordes, 2004).

Introduction Shrimp farming is a lucrative sector in the food production industry. According to SOFIA (2020), 9.4 million tonnes of crustaceans were produced in 2020 worldwide, with 4.96 million tonnes coming from Penaeus vannamei. India is one of the largest global producer and exporter of farmed shrimp. In India, shrimp production increased significantly after introducing Pacific white leg shrimp, Penaeus vannamei, in 2009. Among the cultured shrimp species, Penaeus vannamei is the leading species under culture in India, with an estimated production of 7.12 lakh tonnes (MPEDA, 2020). Intensification of culture and diversification of species provoke the incidence of diseases making diseases the major constraint in aquaculture, leading to tremendous losses. Shrimp diseases are of viral, bacterial, fungal and parasitic origin.

Introduction Organ-On-a-Chip (OOC) is a developing trans-disciplinary technique that shares similarities with tissue engineering and lab-on-a-chip technologies. It has benefited from recent advancements in microtechnology (particularly microfluidics), cell biology, physiology, and tissue engineering and is motivated by the need for reliable, low-cost in vitro drug screening models. It can be characterized as a microfluidic-based perfusion device that facilitates an invitro cell (co-)culture and tries to reproduce certain structure(s), function(s), and important elements of human or animal metabolism of a particular tissue or organ in healthy and pathological physiology. Important features of live organs are such as extracellular microenvironments, spatiotemporal cell-cell interactions, and physiologically important tissue microarchitecture.

Introduction NGOs (Non-Governmental Organizations) are organisations with professional staff that work to lessen human suffering and advance developing nations. The number of Non-Governmental Organizations (NGOs) in India is close to 3.4 million, and they work in a range of sectors, from disaster relief to advocacy for underserved and neglected groups. It is a nonprofit organisation that operates without interference from any governmental body. It is taskoriented and organised by people with common interests in a local, national, or international setting. It performs a variety of services and charitable tasks. Particularly, some are structured around particular concerns, such as health, the environment, or human rights. These make up a sizeable portion of civil society and bring about quick social change. They have developed into a vital and vocal platform for civil society participation in public affairs (Desai, 2014.).

Introduction Fishermen of Gulf of Mannar coast were largely depending on traditional fishing gears, and they were mainly exploiting the coastal fishery resources before 1960’s. After the introduction of trawl gears and mechanized fishing boats during 1960’s fishermen were more comfortable with plenty of fish catch, especially the high-valued demersal shrimps. The fishing effort was also increased at a tremendous pace in this region with the addition of stern trawlers. Due to this increment in the fishing effort, the fishery resources and their life-supporting systems such as coral reefs and sea grass beds are seriouslydisturbed.

Introduction Hokersar wetland (34°06’ N latitude, 74°05’ E longitude), a Ramsar site and a protected wildlife reserve is located in the northwest Himalayan bio geographic province of Kashmir, back of the snow-draped Pir Panchal. The wetland shelters about two million migratory water-fowl during winter that migrate from Siberia and the Central Asian region. The wetland is fed by two inlet streams Doodhganga (from east) and Sukhnag Nalla (from west). It is the only site in Kashmir with remaining reed beds and serves as a migration route for specifically 68 waterfowl species from Siberia, China, Central Asia,and Northern Europe, including the Large Egret, Great Crested Grebe, Little Cormorant, Common Shelduck, Tufted Duck, and endangered White-eyed Pochard (Ramsar, 2021).

Introduction Technology is the application of knowledge and/or equipment in undertaking and accomplishing certain activity. Fisheries technology is a systematically organized knowledge and materials applicable to production problems to help to boost the present level of fish productivity and or extend the existing range of production. Fisheries technologies are wide range of importance; Technological innovation in aquaculture is leading an evolution in aquaculture practices, thereby reducing losses and increasing efficiency. Technology in aquaculture affects many areas of fishery, such as seed production, feed production and management, pest and diseases management, production, harvesting, marketing, processing, etc. Induced breeding technology in Indian Major Carps transformed the growth of aquaculture sector from traditional to intensive aquaculture practices and led to success of modern aquaculture industry. Mechanization in fishing increased the harvest with less time and minimal human drudgery. Fish processing technologies improved product shelf-life, reduced fish loss and added value to the products.

Climate Change - An overview The most studied topic in recent years was climate change, due to its increasing importance. Climate change refers to long-term shifts in temperatures and weather patterns. These shifts may be natural, such as through variations in the solar cycle or due to anthropogenic activities, since the 1800s, human activities have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas. The process of raising the earth’s temperature is known as global warming. Climate change is one result of global warming in different places on the planet. Many people think that climate change means only global warming or an increase in temperatures. But the rise in the temperature is only the beginning of the story. Because in the Earth system everything is connected to one another, changes in one area or in one aspect of the system can influence changes in other areas. The consequences of climate change include flooding, intense droughts, water scarcity, wildfires, rising sea levels, melting polar ice, catastrophic storms and declining biodiversity. Adapting to climate change consequences protects people, businesses, livelihoods, infrastructure and natural ecosystems. It covers current impacts and those likely in the future.