Table of ContentsManagement Objectives and StrategiesCultivation Systems, Its Sources and StagesExtensive MethodsIntensive MethodsEnvironmental Issues and Associated DiseasesConclusionLiterature CitedSeaweed has been cultivated for thousands of years, in especially in Asian countries. Seaweed is primarily used for food, but surprisingly, it has other uses than just subsistence. Large-scale algae productions vary depending on the type of algae; both extensive and intensive methods can be used. Large-scale algae cultivation has both advantages and disadvantages. It is certain that the algae must have been able to act essentially as a biological filter; get rid of inorganic and organic molecules. On the other hand, large amounts of algae can affect overall water quality. This includes light intensity and slow turbidity of water. Diseases, as in many other aquatic productions, are widespread within the algae community, but there are ways to combat them. In this aquaculture essay, the topic of seaweed cultivation, its objectives, methods, and other details are explored. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay Seaweed has been cultivated for thousands of years all over the world. Over the past four hundred years, seaweed has played an important role in Asian cuisine, more than in any other country. Mariculture in Asian countries, such as Japan, China, Korea, and Vietnam, has reached the largest scale of production, contributing 80% of global algal biomass production. China is the largest producer with 60% of global algae production. There are several types of algae produced in marine cultures. As reported by the Food and Agriculture Organization of the United Nations (FAO) in 2018, the most important cultivated seaweed species is Eucheuma, followed by Japanese kelp. Management Objectives and Strategies Seaweed is primarily valued for food, mainly in Asia, where there is a growing demand in Western countries such as the United States of America. Seaweed is grown extensively to aim for large yields with defined properties such as high polysaccharide content and/or good taste. Algae can also be used to produce animal feed, chemicals, paper, fertilizer, biofuels and other renewable products. One goal, like that of many aquaculture production, is to develop improved sustainable methods so that commercial aquaculture, such as large-scale algae farming, has minimal effects on the environment. Due to the growing seaweed aquaculture market, people have become more aware of the effects of aquaculture. such systems. Aquaculture production has the potential to constitute sustainable development. Ways to manage sustainable development may include careful site selection, maintaining the long-term health of the coastal environment, and controlling species and their density. In maintaining the coastal environment, the highest priority is to rebuild depleted resources and habitats. Policies and laws can easily ensure their recovery. To control algae and stock density, a site in Hong Kong where good flushing and low initial storage can be very beneficial. Cultivation systems, its sources and stages The method of cultivation of algae is species specific andis chosen based on the location of the farm. and cultivation facilities. Most algae production is grown extensively in natural waters using only natural light. However, there are areas where algae cultivation is intensive. For this article, I will focus on large-scale commercial seaweed mariculture.Extended MethodsSeabeds. Algae species such as Gracilaria spp. are cultivated in the seabed mainly in Chile and Vietnam. In this method of cultivation, pieces of algae remain anchored to the bottom for several months before the formation of the reproductive organs. Seabed algae are typically grown in shallow, wind-protected bays on sandy or muddy bottoms. In temperate waters, algae grow most intensely in spring and summer due to the dependence on temperature and nutrient concentration. Algae can be grown on lines or ropes suspended over the water surface. The seedlings are attached to ropes which are attached to buoys or rafts. Growing and harvesting time depends on the species of algae. For example, U. pinnatifida in Japan is harvested after 3 months, while S. japonica in China is harvested after 10 to 20 months. The cultivation of algae on ropes and lines depends on many factors, mainly the hydrological and chemical conditions of the cultivation site. There should be a balanced ratio of nitrogen and phosphorus as well as moderate currents and wave action. Net culture is usually used on Porphyra and Cladosiphon species. The mesh size of the nets is important for algae cultivation and can be adjusted according to the external morphology of the plants. Cultures begin by collecting spores, then the spores are moved to nets. When the spores develop, the nets are changed to a larger size until harvest. Species grown in nets are generally harvested about three to four times per year.Intensive MethodsTanks. Introduced in the 1970s, tank cultivation produces a high yield compared to other methods. Algae grown in tanks are cultivated in order to purify the effluent of farm animals. Tank cultivation requires high energy consumption and the use of expensive materials; this is generally too expensive for commercial-scale production. The quantity yield depends on many factors such as irradiation, light intensity, depth of the tanks. The density of algae grown in a tank can also affect product yield. Ponds. Algae species can be grown on the bottom of ponds or suspended from ropes in a pond. Ponds can be fed with sea water or a mixture of sea water and river water. If nutrient levels are low in a pond, fertilizers can be used. Gracilaria is widely cultivated in ponds in China and Vietnam. In these ponds, the depth varies from 20 to 30 cm. Usually the product is harvested after 30 to 45 days. Integrated agriculture with marine organisms. Integrated agriculture involves the combined cultivation of marine organisms and algae. There are three methods in integrated agriculture: algae are grown in ponds/reservoirs and receive effluent from fish or invertebrates and algae are grown in ponds with fish, crustaceans and molluscs and the algae are grown near sea cages with animals. The use of algae in polyculture is becoming increasingly popular due to their ability to assimilate inorganic and organic nutrients present in animal waste.Environmental Issues and Associated Diseases Like all large-scale production, many challenges are faced. First, seed quality is a major issue in the algae industry due to propagation techniques from a limited gene pool. To combat this, there has been talk of introducing non-native species, also called invasive species, to mix up the genetic makeup. Invasive species can still have the potential to cause massive damage to environments. Due to the potentially negative impacts, policies are limiting or completely abandoning the use of non-native genotypes in seaweed aquaculture. On the other hand, algae cultivation has been shown to have positive effects on the environment due to its ability to remove organic and inorganic waste from water, thereby reducing eutrophication. However, large commercial seaweed crops can certainly harm the environment. The greatest damage is caused to shallow lagoons and small bays. Due to the shallow environment that lagoons and bays typically provide, large amounts of algae can decrease light intensity, increase sedimentation, and even slow water movement. Diseases always seem to find a way into production. Due to the intensification of agriculture, there has been an increase in red rot and "chytrid" diseases. There has also been a decline in the production of many carrageenophytes which are credited with rising sea temperatures. Rising temperatures can cause the dreaded thallus bleaching, making the algae more susceptible to disease. To treat this, chemical treatments can be used but can cause possible side effects to the product. Another disease that is quite common on seaweed farms is known as “ice-ice.” This affects algae when they are in low light, slow water movement, or low nutrient concentrations. The best way to resolve this disease is to simply move the algae to another location that provides an optimal environment. Keep in mind: this is just a sample. Get a personalized article from our expert writers now. Get a Custom Essay Conclusion In conclusion, seaweed cultivation takes place in more than 50 countries, with the main producers being China, Indonesia, Japan, and the Republic of Korea. The importation of seaweed is extremely important for these seaweed productions, with China being the most important partner in international trade. Edible and inedible seaweed are exported from China worth over US$200 million in 2016. While China is the largest country in terms of trade, Japan produces seaweed essential for cooking. Japanese wakame, nori and kombu are widely used in Japanese cuisine and exported around the world. Japan's annual seaweed exports have been valued at US$200 million. Literature CitedAlveal, K., Romo, H., Werlinger, C., Oliveira, EC, 1997. Mass culture of the agar-producing alga Gracilaria chilensis (Rhodophyta) of spores. Aquaculture 148, 77-83. https://doi.org/10.1016/S0044-8486(96)01415-9Caddy, JF, 1999. Fisheries management in the 21st century: will new paradigms apply? Reviews in Fish Biology and Fisheries 9, 1–43. https://doi.org/10.1023/A:1008829909601Ding, H., Ma, J., 2005. Simultaneous infection with red rot and chytrid diseases in Porphyra yezoensisUeda. J Appl Phycol 17, 51-56. https://doi.org/10.1007/s10811-005-5523-6Feng, YY, Hou, LC, Ping, NX, Ling, TD, Kyo, CI, 20, 477-483.10811-007-9299-8