More and diverse contributions from aquaculture

Aquaculture is literarily and traditionally recognised as a collection of “farming finfish, shellfish and aquatic plants,” or as “the raising of water animals such as fish for food, or the growing of plants in water for food” (https://dictionary.cambridge.org/dictionary/english/aquaculture). In some agencies, aquaculture has been defined as the “breeding, rearing, and harvesting of fish, shellfish, algae, and other organisms in all types of water environments” (https://oceanservice.noaa.gov/facts/aquaculture.html/), although in some occasions, mariculture is used to indicate specifically aquaculture activities in marine and estuary environment. In general, aquaculture has been considered as a food production sector in our society, and over the last few decades, aquaculture has indeed been the fastest-growing sector of food production across the world.1 In addition to its significant contributions to the production of food, protein source, delicious food selection, and also to rural development, aquaculture activities have increasingly been used for conservation purposes including species and biodiversity conservation, habitat restoration and ecosystem service.1 In this issue, a group of scientists published an article, analysing the diversification of aquaculture activities through the investigation of literature, and then the definitions and roles of aquaculture were defined from an environmental and ecological point of view.1 Notably, “commercial aquaculture” should refer to the literal and traditional explanation of aquaculture, and is probably the main aspect of the aquaculture industry. The contribution of aquaculture in species conservation or habitat protection should be termed “conservation aquaculture,” and this kind of aquaculture has contributed significantly to the conservation of endangered species of fish, for example, the Kootenai white river sturgeon Acipenser transmontanus, and also two other species of sturgeons, the Chinese sturgeon A. sinensis, the Yangtze or Dabry's sturgeon A. dabryanus, in Changjiang (Yangtze) River, the latter two of which are now only relied on artificial reproduction to maintain the population or the species (Prof Jianbo Chang in Wuhan University, Personal Communication). Two other definitions of aquaculture in this article1 are restorative aquaculture and regenerative aquaculture, and it should be desirable and important to see more contributions of aquaculture in aquatic ecosystem service in future. It may not be believable if one says luxury products can be produced in aquaculture. In fact, pearls have an enduring attractiveness for jewellery, and freshwater pearl culture can be dated back to more than 2000 years ago in China, although its modern freshwater pearl culture has only a history of less than a century.2 Marine pearl culture is also a profitable and historical aquaculture activity with a global importance in countries or regions such as in China, Japan, some south-eastern Asian countries, some European countries, and Latin America. In this issue, Saucedo et al.3 summarised briefly the history of marine pearl culture along the Pacific and Caribbean coasts of many Latin American countries, outlined the current marine pearl aquaculture techniques and activities in these countries, and proposed an economically profitable and environmentally friendly pathway and strategies to reestablish Latin America as a major pearl producing region,3 which will provide a much more diversified selection of variously coloured and lustrous pearl ornaments. Also in this issue, a review article was devoted to the analysis of carotenoid production through the culture of microalgae, and the possible biotechnological approaches to improve the production of various carotenoids in different species of algae using either organic or inorganic nutrients were highlighted in this article.4 It is considered that a wide range of biomedically important bioactive compounds synthesised in algae can be produced through the culture of microalgae. It is apparent that aquaculture will continue to provide food and protein, but the roles and activities of aquaculture have become diversified with the production of a wide range of products, and simultaneously with significant value in nature conservation.