Blue Lupin for White Shrimp (Litopenaeus vannamei)

Formulated feeds used for the growing production of carnivorous fish and crustaceans generally have a high protein content still met mostly by fish meal supply. Maintaining the steady and enormous growth of aquaculture production requires practical alternative protein sources. Terrestrial protein sources have been the focus of feed research for more than twenty years. Many studies test legumes like field peas, lupin and faba bean. Several different cultivars of lupin have been tested with different fish species mainly in Australia. The results of these studies are promising for example for salmon and seabass but. Lupin diets with a relevant replacement level for high value crustaceans are tested in the present study. An experimental diet (Basis) with 30% fish meal as main protein source was formulated. Lupinus angustifolius kernel meal was added as 10, 20 and 30 % of the diet, incrementally replacing fishmeal. All diets were balanced to meet the requirements of L. vannamei in the grow out phase, concerning energy content, protein and amino acid profile, lipid and fatty acid composition, vitamins and minerals. These diets were compared with a commercial controlFeeding experiments were conducted over 8 weeks in a RAS device, with 18 separate 50 l tanks. Mean survival rate of the shrimps was 65% across all treatments. Mean biomass of animals fed with high lupine levels (L30) was significantly lower than in control diets (Basis and Commercial control) and L10 after 8 weeks. Metabolic analyses showed malnutrition of animals fed the L30 diet concerning glucose and triglyceride levels, although appropriate protein provision was attained with all experimental feeds. The total haemocyte count showed significantly higher counts in animals fed the L10 diet, which hints at an elevated immune capacity of these animals. This is an intriguing result concerning immunostimulation in cultured animals and needs further investigation. Untreated lupine meal can be used as an alternative protein source at rates of up to 10% (-20%) of the total feed (= 30-40% of animal protein)

Role of deposit-feeding sea cucumbers in integrated multitrophic aquaculture: progress, problems, potential and future challenges

There is significant commercial and research interest in the application of sea cucumbers as nutrient recyclers and processors of particulate waste in polyculture or integrated multitrophic aquaculture (IMTA) systems. The following article reviews examples of existing IMTA systems operating with sea cucumbers, and details the role and effect of several sea cucumber species in experimental and pilot IMTA systems worldwide. Historical observations and quantification of impacts of sea cucumber deposit-feeding and locomotion are examined, as is the development and testing of concepts for the application of sea cucumbers in sediment remediation and site recovery. The extension of applied IMTA systems is reported, from basic piloting through to economically viable farming systems operating at commercial scales. The near-global recognition of the ecological and economic value of deposit-feeding sea cucumbers in IMTA applications within existing and developing aquaculture industries is discussed. Predictions and recommendations are offered for optimal development of sea cucumber IMTA globally. Future directions within the industry are indicated, and key areas of ecological, biological and commercial concern are highlighted to be kept in mind and addressed in a precautionary manner as the industry develops

UP-SCALLING THE APPLICATION OF HYDROGEN PEROXIDE AS DESINFECTION METHOD IN A COMMERCIAL RAS REARING ATLANTIC SALMON (Salmo salar): A CASE STUDY

Introduction Disinfection is a very important part of recirculation aquaculture systems (RAS). RAS allows for controllable environments in which main variables relevant to animal welfare and a successful production can be manipulated as required to improve efficiency and profitability. Common disinfection methods include chemical disinfectants, antibiotics, biocides, UV radiation and ozone. They can be used to treat disease outbreaks, or to reduce the bacterial load of the system which otherwise could lead to the overgrowth of potential pathogens or opportunistic bacterial groups competing with biofilter bacteria for space and resources. Ozone is the most used disinfection method requiring expensive technology and trained stuff. Hydrogen peroxide (H2O2) has been on focus as a “green” alternative. High H2O2 doses are associated with acute toxicity symptoms for some species. Low doses are harmless, offer additional system oxygenation and contribute to water quality improvement. After testing the use of low doses in a small research RAS, the present study aims to describe the first case study up-scaling a continuous hydrogen peroxide application to commercial fish production in RAS with focus on the determination of required concentrations, application monitoring and variations on microbiome composition. Material and Methods The present study was performed at RAS facilities of Danish Salmon A/S in Hirtshals, Denmark, one of the European pioneers in rearing salmon in land based aquaculture facilities and producing about 1.200 metric tons/year of Atlantic salmon (Salmo salar). Two identical Grow-out RAS with own water treatment elements and eight pre-grow tanks were used as treatment and control systems to compare the effects of continuous H2O2 application in combination with ozone to common operational practice. Oxygen Cones and additional aeration stones ensured the basic Oxygen supply in the tanks. Defined H2O2 quantities were applied with a dosing lance connected to a peristaltic pump and an International Bulk Container with PERSYNT® 50, (EVONIK Industries) into the distribution pipe feeding a collection tank from where the water was evenly distributed to all tanks. Based on previous experiments, a final dosing of about 20 l/h was projected. Water samples were collected at the start (REF) and after slowly enhancing the dosage over time (24h and 30d), for the determination of the total microbial count (certified chromogenic Compact Dry TC plates from R-Biopharm), microbial viability (BacLight Viability Kit) and bacterial community composition (FISH). Water parameters (Ammonia, Nitrite, Nitrate, Phosphate, COD, Turbidity and H2O2 concentration) and production related information (feeding rate, fish biomass, oxygen consumption, ozone production) were also regularly evaluated. Results and Discussion H2O2 application started on August 06, 2020 with 1 l/h (0.51mg/L) and was increased over time up to 14 l/h (7.09 mg/L) (Fig1). On September 30, 2020 the application was stopped due to detected changes on feeding behavior of the fish as well as incorrect redox measurements in the treatment system which could probably be attributed to accumulation of oxidative species not having enough organic material to react. The test and control systems had similar biomass during the experimental period (test: 34.9-52.5 tones and control 36.4-51.4 tones) and the feed intake was accordingly adjusted (mean feed intake test: 496 kg/day; control 450 kg/day). The oxygen demand registered on the treated system (82 l/min - 90 l/min) was lower than the control (104 l/min - 115 l/min). In general, there was a reduction of turbidity and decreased nitrogen species and phosphate in the treated system. System maintenance (biofilter cleaning and backwashing) might had influenced the COD and total microbial counts measurements. Total microbial counts reflected a steady increase in the number of CFU/ml in both systems (Fig.2) and evidenced microbial accommodation. There was an increased rate of microbial mortality according to the viability results with higher values in the treated system reflecting the longer exposure of this system to oxidative stress (Fig 3). The community composition varied according to the treatment (Fig.4) and changes in the abundance of the different bacterial groups analyzed could be attributed to variable vulnerability of members of these groups to the disinfection potential of H2O2 or its combination with ozone

Brown shrimp (Crangon crangon) processing remains as ingredient for Litopenaeus vannamei feeds: Biochemical characterisation and digestibility

Processing remains of brown shrimp, Crangon crangon, account for up to 60 % of the catch while only the small muscle fraction is used for human consumption. Incorporation into aquafeeds for high-valued species would reduce waste, create by-product value and promote sustainable aquaculture development. A detailed chemical characterisation of the remains from mechanically peeled brown shrimp was made and apparent nutrient digestibility coefficients in Litopenaeus vannamei were investigated. Brown shrimp processing remains (BSPR) contain substantial amounts of key nutrients (521 g⋅kg-1 crude protein, 74 g⋅kg-1 total lipid, 15 MJ⋅kg-1 gross energy) and valuable functional ingredients were detected (cholesterol, astaxanthin). Apparent energy (82 %) and protein (86 %) digestibility coefficients reveal good bioavailability of these nutrients. Dry matter digestibility was lower (64 %) presumably due to the high ash content (244 g⋅kg-1). The amino acid profile meets dietary requirements of penaeid shrimp with high apparent lysine and methionine digestibility coefficients. Analysis of macro- and micro minerals showed reasonable levels of required dietary minerals (phosphorus, magnesium, copper, manganese, selenium, zinc) and apparent copper digestibility was high (93 %). Contamination levels present in BSPR were below European standards acceptable for human consumption. Processing remains of brown shrimp have a high potential as alternative feed ingredient in sustainable diets for L. vannamei in recirculating aquaculture systems

Redox stratification drives enhanced growth in a commercially important deposit-feeding invertebrate: implications for bioremediation and integrated aquaculture.

Effective and affordable treatment of waste solids is a key sustainability challenge for the aquaculture industry. Here, we investigated the potential for a deposit-feeding sea cucumber, Holothuria scabra, to provide a remediation service whilst concurrently yielding a high-value secondary product in a land-based recirculating aquaculture system (RAS). The effect of sediment depth, particle size and redox regime were examined in relation to changes in the behaviour, growth and biochemical composition of juvenile sea cucumbers cultured for 81 d in manipulated sediment systems, describing either fully oxic or stratified (oxic-anoxic) redox regimes. The redox regime was the principal factor affecting growth, biochemical composition and behaviour, while substrate depth and particle size did not significantly affect growth rate or biomass production. Animals cultured under fully oxic conditions exhibited negative growth and had higher lipid and carbohydrate contents, potentially due to compensatory feeding in response to higher microphytobenthic production. In contrast, animals in the stratified treatments spent more time feeding, generated faster growth and produced significantly higher biomass yields (626.89 ± 35.44 g m-2 versus 449.22 ± 14.24 g m-2; mean ± SE). Further, unlike in oxic treatments, growth in the stratified treatments did not reach maximum biomass carrying capacity, indicating that stratified sediment is more suitable for culturing sea cucumbers. However, the stratified sediments may exhibit reduced bioremediation ability relative to the oxic sediment, signifying a trade-off between remediation efficiency and exploitable biomass yield

Price Discovery and the Accuracy of Consolidated Data Feeds in the U.S. Equity Markets

Both the scientific community and the popular press have paid much attention to the speed of the Securities Information Processor, the data feed consolidating all trades and quotes across the US stock market. Rather than the speed of the Securities Information Processor, or SIP, we focus here on its accuracy. Relying on Trade and Quote data, we provide various measures of SIP latency relative to high-speed data feeds between exchanges, known as direct feeds. We use first differences to highlight not only the divergence between the direct feeds and the SIP, but also the fundamental inaccuracy of the SIP. We find that as many as 60 percent or more of trades are reported out of sequence for stocks with high trade volume, therefore skewing simple measures such as returns. While not yet definitive, this analysis supports our preliminary conclusion that the underlying infrastructure of the SIP is currently unable to keep pace with the trading activity in today's stock market.Comment: 18 pages, 20 figures, 2 table

Effect of diet on growth, survival and fatty acid profile of marine amphipods: implications for utilisation as a feed ingredient for sustainable aquaculture

Rapidly expanding fed aquaculture demands high-quality, sustainable nutrient sources for utilisation as dietary ingredients. Exploring the potential of under-utilised resources from other industries is imperative to replace finite natural resources, such as fish meal. Marine gammarids may be an excellent source of essential fatty acids; however, their aquaculture using formulated diets remains untested in terms of survival, growth and nutritional value of the cultured product. Here, juveniles of 2 marine gammarid species, Gammarus locusta and Echinogammarus marinus, were maintained in controlled feeding experiments with 2 marine diets (Ulva spp. and Fucus spp.) and 2 terrestrial diets (lupin meal and carrot leaves). G. locusta exhibited higher survival rates, particularly when fed carrot leaves, an agricultural waste product. Fatty acid profiles of the resulting G. locusta product appear well suited for marine finfish nutrition, indicating high suitability of G. locusta as an aquaculture diet source. In contrast, whilst E. marinus may provide beneficial fatty acid profiles for aquatic animal nutrition, its poor growth performance in this study indicates that further dietary/culture research is required for this species. Our results indicate, for the first time, that marine gammarids are capable of trophic upgrading and can use non-marine diets for healthy growth in culture, but their suitability as a formulated feed ingredient for specific fish or crustacean species needs to be investigated individually. Future research should include the development of optimal large-scale production as well as investigation of optimal methods of inclusion of gammarids as feed ingredient for target aquaculture species