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Omega-3 long-chain polyunsaturated fatty acids (n-3 LC PUFAs) and vitamin D3 are essential components of human nutrition. A regular human diet is highly deficient in n-3 LC PUFAs. Fish like salmon are highly recommended in the human diet as they are a major source of high-value n-3 LC PUFAs and vitamin D3. The levels of these nutrients have been decreasing over the last few years in farmed salmon, whose production urgently needs sustainable sources of these nutrients. The microalga Nannochloropsis gaditana (NG) is known for its naturally high potential for the production of eicosapentaenoic (EPA, 20:5 n-3) fatty acid. A commercial diet for Atlantic salmon was supplemented with 1% and 10% of spray-dried NG grown under controlled conditions for a high EPA content. Salmon were harvested on day 49, following which, boneless and skinless salmon meat was recovered from fish and analyzed for the fatty acid profile, total fat, and vitamin D3. Vitamin D3, EPA, and docosapentaenoic fatty acid (DPA, 22:5 n-3) levels were significantly increased (p < 0.05) by supplementing the basal diet with 10% NG, thus, NG represents a novel, functional, natural ingredient and a sustainable source of n-3 LC-PUFAs that can raise the levels of healthy fats and vitamin D3 in farmed salmon meat.

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Sustainability in aquaculture is a necessity of the future, not only as the most promising means of supplying the protein that the world will require to feed its growing population but to offer needed conservation of the world’s ocean resources. The use of wild fish inputs in farm-raised fish outputs has been a primary concern of sustainability in aquaculture production. Herbivorous fish are more efficient converters of protein into fish flesh. Species of the genus Medialuna fish have been reported as a fast-growing, short-lived species. The native fish Acha (Medialuna ancietae Chirichigno 1987) in the Northern part of Chile is an over-exploited fish that has been associated with aquatic vegetation as a food source. We studied the feeding habits and nutritional composition of M. ancietae. For this, we developed a reference collection of marine macroalga (epidermis and nutritional composition) observed in the diet of individuals of this species for the study of digestive material. More than 90% of the components found were marine macroalgae, indicating that M. ancietae is an herbivorous fish. Compared to non-herbivorous fish our results showed that most of the nutrients present in the Medialuna diet are found at much lower levels including n-3 long-chain polyunsaturated fatty acids (49.7%) and protein (13–60%). M. ancietae meat provides essential components of human nutrition with a significant protein content (18.99 ± 0.26%) and 268 ± 5.9 mg/100 g of the essential n-3 long-chain polyunsaturated fatty acids. Most fed aquaculture non-herbivorous species rely on wild-captured fish for these essential nutrients, while M. ancietae can obtain and concentrate them from potentially cultivable macroalgae. M. ancietae has potential for sustainable aquaculture production as a contribution to nutrition security and the re-stocking of wild populations.

The exponential growth of aquaculture over the past 30 years has been accompanied by a parallel increase in the use of antimicrobials. This widespread use has had negative effects on animal, human and environmental health and affected the biodiversity of the environments where aquaculture takes place. Results showing these harmful effects have been resisted and made light of by the aquaculture industry and their scientific supporters through introduction of misunderstandings and misinterpretations of concepts developed in the evolution, genetics, and molecular epidemiology of antimicrobial resistance. We focus on a few of the most obvious scientific shortcomings and biases of two recent attempts to minimise the negative impacts of excessive antimicrobial use in Chilean salmon aquaculture on human and piscine health and on the environment. Such open debate is critical to timely implementation of effective regulation of antimicrobial usage in salmon aquaculture in Chile, if the negative local and worldwide impacts of this usage are to be avoided.

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Sustainability in aquaculture is a necessity of the future, not only as the most promising means of supplying the protein that the world will require to feed its growing population but to offer needed conservation of the world’s ocean resources. The use of wild fish inputs in farm-raised fish outputs has been a primary concern of sustainability in aquaculture production. Herbivorous fish are more efficient convertors of protein into fish flesh. Species of the genus Medialuna fish have been reported as a fast-growing, short-lived species. The endemic Acha fish (Medialuna ancietae) in the Northern part of Chile is an over-exploited fish that has been associated with aquatic vegetation as a food source. We studied the eating habits and nutritional composition of M. ancietae. For this, we developed a reference collection of marine macroalga (epidermis and nutritional composition) observed in the diet of individuals of this species for the study of digestive material. More than 90% of the components found were marine macroalgae, indicating that M. ancietae is an herbivorous fish. Compared to non-herbivorous fish our results showed that most of the nutrients present in the Medialuna diet are found at much lower levels including n-3 long-chain polyunsaturated fatty acids (49.7%) and protein (13–60%). M. ancietae meat provides essential components of human nutrition with a significant protein content (18.99 ± 0.26%) and the presence of n-3 long-chain polyunsaturated fatty acids. Most fed aquaculture non-herbivorous species rely on wild-captured fish for these essential nutrients, while M. ancietae can obtain and has the ability to concentrate them from potentially cultivable macroalgae. M. ancietae has potential for a sustainable aquaculture production as a contribution to nutrition security and re-stocking of wild populations.