Mariculture In India: Understanding Ecosystems for Sustainable Marine Food Production

To date, the net contribution of global mariculture to the world's fish supplies, along with the changes in this contribution, has been briefly discussed in this chapter. Primarily, the industrial sub-sector emphasizes how mariculture is integrated into the global marine food system. However, the greatest contribution to global fish production and food security has come from inland aquaculture. Although the dependency on marine ingredients persists and the reliance on terrestrial ingredients has increased, significant improvements in aquaculture feed efficiency and fish nutrition have also been made. This has resulted in a decrease in the fish-in-fish-out ratio for all fed species. This ratio is expected to increase over the next few decades as global demand for seafood rises and fisheries catch remains stagnant. The marine and brackish subsector is of particular interest for examination, as the importance of mariculture increases due to its expanding impact on global mariculture growth, as well as its recognized detrimental effects on fish populations and maritime security. The ecological services provided by the cultivation of molluscs and seaweed are becoming more widely acknowledged. These services are being quantified, valued, and developed into a market to increase production.

In the contemporary world, where the demand for proteins and minerals is rapidly increasing, the need for seafood is growing substantially. However, traditional fishing methods are insufficient to meet this demand, especially with a rising population. In this context, mariculture emerges as an innovative approach that can effectively address the limitations of wild fishing. Although highly efficient, mariculture also has certain challenges that need to be addressed. This chapter discusses the current status of mariculture, with a focus on India, and the technologies that have been implemented. Furthermore, it highlights the need for further development and governance to overcome these challenges and achieve efficient mariculture practices. Beyond serving as a source of human consumption, mariculture plays a vital role in the country’s economy and employment.

Sustainable mariculture is the practice of utilizing marine resources in an integrated method using technologies with economic and environmental sustainability without exploiting the natural resources needed for future generations. The growth of mariculture is doubling every decade, but the management and responsibility of those undertaking the activity to ensure sustainability are declining. The development of culture technology for marine organisms under controlled conditions in open ocean environments, beyond significant coastal influence, is a topic of the hour in mariculture. A new approach in mariculture that invites much-focused research on ensuring sustainability includes seed production technology, cost-effective feed, growout culture technology, and the social responsibility of stakeholders. Mariculture is the fastest-growing food-providing sector for the global population, with a minimal focus on environmentally sustainable practices regarding the degradation of coastal environments and the management of coastal resources. Integrated mariculture combines various farming methods, including Integrated Multitrophic Aquaculture (IMTA) and aquasilviculture, which involves combining mangrove planting with aquaculture. Modern integrated mariculture should be developed to facilitate the sustainable expansion of this sector in coastal and marine ecosystems, thereby addressing the global increase in seafood demand with a new paradigm of more efficient food production systems. Hence, mariculture as a whole must focus its growth on harnessing coastal resources more effectively by ensuring sustainability and the responsible use of marine resources.

Mariculture is an activity primarily focused on producing aquatic food, and many people living along the coast depend on it for their livelihood and income. Due to population growth and rising demand for seafood products, it has rapidly expanded. Maricultural activities discharge particulate organic matter, nitrogen, phosphorus, antibiotics, and hormones into the marine ecosystem. Large areas of mangrove and coastal regions have been converted into shrimp and fish ponds. It also has unintended predation impacts on non-target species. These have the potential to alter, destroy, or disrupt habitat, trophic structures, disease transmission, and genetic capabilities. As a result, mariculture affects biodiversity, which will be reflected in the supply of ecosystem services. Mariculture development must be sustained to promise economic and environmental benefits.

In the fisheries sector, mariculture serves as a growing backbone for the nutritional animal producing industry. Despite the progression in the farming practices for production maximisation, loss occurs through diseases by a variety of pathogens. Hence, disease management is an important criterion that must be implemented at the proper time for the prevention of diseases and also to protect cultured organisms from pathogens. Aquatic health management requires adequate knowledge to overcome the practical problems encountered in the mariculture sector. The important pathogens are categorised into major groups such as viruses, bacteria, fungi, and parasites. The viral diseases in the mariculture environment predominate with the iridoviral disease, lymphocystis disease, nervous necrosis virus disease, and rhabdoviral disease. The major bacterial diseases encountered include vibriosis, winter ulcer, photobacteriosis, and furunculosis. One of the leading causes of other infections in the saline aquaculture practices is parasites, especially in cage cultures. Disease clearance requires some practical prophylactic and therapeutic actions to eradicate them. Disease treatments using chemicals cause various problems to the fish by settling as residues in the body, polluting the environment or harms the other organisms in the surrounding environment. To avoid this and to effectively eradicate the problematic organisms, some new environmentally friendly measures can be taken to control the pathogens from the mariculture environment. Therefore, the drawbacks of using chemicals for treatments can be reduced, and better results can be expected to ensure a sustainable mariculture environment. 

Fish play a crucial role in ensuring global food security, particularly in developing countries, where the demand for additional protein sources continues to rise alongside population growth. Aquaculture, the fastest-growing sector in food production, focuses on the breeding and rearing of fish and other aquatic species. Within this industry, fish nutrition and feeding are critical for sustainable growth and overall productivity. The use of feed ingredients that support growth while providing a balanced supply of essential nutrients is fundamental to maintaining healthy fish and, by extension, healthy consumers. Scientific research has significantly advanced the development and efficacy of aquafeeds, ensuring that both farmed and wild fish receive optimal levels of essential nutrients, including vitamins, fatty acids, and amino acids, to maximize growth, health, and survival. Freshly formed resources include macroalgae, transgenic-raised, HUFA-producing plants, and microorganism biomass. Newly explored feed resources include herbivorous zooplankton, such as Antarctic krill, and various plant-based ingredients. Incorporating these resources can help shift carnivorous species toward lower trophic-level diets, thereby enhancing production efficiency and product quality. While these ingredients contribute, to some extent, to human nutrition, the long-term goal of mariculture in the 21st century is to rear carnivorous fish primarily on plant-based resources. The aquaculture industry has significant potential to reduce its reliance on conventional fishmeal. Improvements in feed composition and nutritional efficiency can lead to higher fish yields, lower feed costs, and reduced waste, ultimately decreasing the environmental nutrient load associated with intensive fish farming.

Marine biotechnology in pharmaceutical and food industries is a growing sector supported by expanding reach and financial resources worldwide. This study evaluates 620 publications and 29 projects, identifying the most promising technologies and business trends to advance materials development and improve performance. Omics, drug evaluation, and bioinformatics technologies are driving medical research and are considered essential tools to develop novel materials and candidate organisms for commercial applications. Techniques to optimize living conditions, harvesting, and purification methods, combined with recombinant technologies, are important to maximize commercial and industrial use, particularly in food and nutraceutical programs. Growth in this sector has been driven by increasing consumer demand for healthy ingredients that provide sustained health benefits, along with less stringent regulations compared to pharmaceutical products. Although this review has several limitations—particularly the author’s subjectivity in classifying publications and an imperfect selection of projects analyzed—it offers insights into trends most relevant in Europe. It does not provide a fully quantitative assessment of the current literature in drug and food applications, but it highlights the development of basic research and its implementation during the period. As such, promoting evidence-based strategy creation is the primary recommendation for overcoming barriers that limit seafood commercialization.

India is viewed as a promising landscape for expanding mariculture and addressing the numerous challenges faced by the food industry. Despite the many benefits of India's green, blue, and silver revolutions, intensive aquaculture techniques have raised environmental concerns in aquatic environments, causing significant concern. Improved farm management practices, integrated farming, selective chemical usage, proper disease management, the development of low-cost and novel technologies, technology transfer for feed management, and other methods could help mariculture achieve long-term sustainability.