Precision fish farming: a new framework to improve production in aquaculture

Aquaculture production of finfish has seen rapid growth in production volume and economic yield over the last decades, and is today a key provider of seafood. As the scale of production increases, so does the likelihood that the industry will face emerging biological, economic and social challenges that may influence the ability to maintain ethically sound, productive and environmentally friendly production of fish. It is therefore important that the industry aspires to monitor and control the effects of these challenges to avoid also upscaling potential problems when upscaling production. We introduce the Precision Fish Farming (PFF) concept whose aim is to apply control-engineering principles to fish production, thereby improving the farmer's ability to monitor, control and document biological processes in fish farms. By adapting several core principles from Precision Livestock Farming (PLF), and accounting for the boundary conditions and possibilities that are particular to farming operations in the aquatic environment, PFF will contribute to moving commercial aquaculture from the traditional experience-based to a knowledge-based production regime. This can only be achieved through increased use of emerging technologies and automated systems. We have also reviewed existing technological solutions that could represent important components in future PFF applications. To illustrate the potential of such applications, we have defined four case studies aimed at solving specific challenges related to biomass monitoring, control of feed delivery, parasite monitoring and management of crowding operations

Implications for the environment of using adaptive feeding systems in the cage culture of Atlantic salmon

The use of adaptive feeding systems to deliver feed remotely to Atlantic salmon (Salmo salar) cages has the potential to improve the localised environment through a reduction in particulate waste. This can be achieved through improved growth and lower Feed Conversion Ratio (FCR). The aim of this project was to assess whether adaptive feeding systems confer any environmental benefit at salmon farms through by comparing two fish farm sites, one that uses a Computer Aided System (CAS) adaptive feeding system (AKVAsmart UK limited, Inverness, Scotland) (Portavaide fish farm) and one using hand feeding (Rubha Stillaig). This investigation comprised of 3 elements: 1) a comparative assessment of the quantity and nutrient composition of particulate waste material emanating from the cages; 2) collection of benthic samples plus a video survey along transects at each site including a reference station, with an analysis of differences in benthic fauna, sediment grain size and sediment nutrient composition; and 3) comparison of the distribution of waste under each feeding regime using a GIS-based modelling approach. Particulate waste was collected via sediment traps. Uneaten feed was caught in only 3 out of 184 separate collections and thus no estimate of feed loss for each feeding system could be made. Samples were analyzed for total solids (TS), faecal solids (FS), faecal carbon (FC), faecal nitrogen (FN) content and faecal sedimentation rate (FSR). The highest deposition occurred under the cages and decreased with increased distance from the cage centre. Maximal deposition of TS at Portavadie was higher than at Rubha Stillaig when feed was included, although average TS, FS, Fe and FN per tonne of production did not significantly vary between sites. Carbon sedimentation rate was analyzed using regression analysis and a General Linear Model Factorial ANOVA on faecal waste only and showed no significant differences between sites and, therefore, no difference between feeding methods . There were no differences observed in the diversity and abundance of benthic species under the two feeding systems. By the end of the production period all stations out to 25m from the cage edge were dominated by Capitella capitata at both sites, this species proving a useful indicator of the impact of nutrient deposition. The analysis suggested that Heteromastus filiformis and Corophium sp. provided useful indicators of the onset of nutrient enrichment. Measurement of carbon and nitrogen levels and particle size in sediment showed no difference between sites. Variations between sites in species abundance and diversity and sediment carbon and nitrogen levels reflected the different sediment conditions prevalent at the start of the sampling period. Univariate and multivariate analysis showed there was no difference in species diversity and abundance between the sites as a result of using adaptive feeding systems. Horizontal cage movement, measured at up to 10m, reduced the predicted settlement under the cage by 23% and 11 % for feed and faecal distribution respectively. There was no significant difference in the predicted settlement of waste particulates under adaptive and hand feeding. The GIS model prediction of carbon flux (g C m-2 15-days-1) was validated for faecal settlement using sediment trap data where predictions agreed well with observations from Portavadie fish farm, with an accuracy of ± 53.1 % when all stations were included, improving to ± 27.6% when deposition under the cage was excluded. Overall, the approaches used did not identify specific differences between sites that used adaptive feeding and hand feeding methods. The growth period using the adaptive feeding system was approximately nine weeks shorter than under hand feeding, however, which could be used constructively to increase the fallowing period whilst maintaining current levels of production. This would benefit the localised benthos by increasing the time available for recovery before further production takes place and thus the CAS Adaptive Feeding System could be used as part of a broader sustainable farming strategy for fish cultur