MarTERA:AQUACULTURE OPERATIONS with RELIABLE FLEXIBLE SHIELDING TECHNOLOGIES for PREVENTION of INFESTATION in OFFSHORE AND COASTAL AREAS

Background and objective: In the salmon aquaculture industry, the two greatest environmental risks are ectoparasite infestations and the escape of farmed fish. To tackle these problems, new farming technologies are being developed and among the diverse approaches is the modification of the cage structure to shield the salmon from ectoparasites. Recent innovations in cage design have involved placing a lice barrier in the upper section of salmon cages, either as a full skirt around cages or as an internal ?snorkel?. These barriers are used to prohibit infection by parasites as they stop encounters between parasites and salmon in the upper depths (e.g. 0-10 m) of the water column. While the use of these barriers have skirts and snorkel technologies are more and more used in full-scale salmon farms by the industry with positive effects in reducing lice loads, but there were still unknowns regarding the long/mid-term effects of these new farming technologies on the total structural integrity of the cage and farm itself. This project delivers the necessary knowledge base and by developing necessary tools and methods for safe and reliable operations of these new type of cages. It investigates and improves the use of flexible shielding skirts for prevention of ectoparasite infestation in relation to salmon farming, investigate the effect of marine organisms growth on these structures and suggests innovative, safe and efficient underwater monitoring procedures. Specific Scientific & Technological Results: The FLEXAQUA project has, improved the understanding of the behaviour of such structures under various environmental conditions (currents, waves) and the effect of marine organism growth on the structural integrity, developed new techniques to detect 3-dimensional structural damages, and secured the operations with cost-efficient monitoring systems. 1.By performing field measurements and lab scale trials, the project has developed new understanding on the hydrodynamics around and inside these structures and develop a new numerical model for marine high flexible structures to ensure safety and reliability. 2.Study and predict the long/mid-term effects of growing marine organisms on these flexible structures. Through implementation of analyses of video-images for detection of features of interest (3D objects, nets, fishes, marine growth) using in-house developed algorithm a fish net health estimation solution has been developed, which assesses and predicts marine growth cover on nets. 3.New procedures to detect and monitor damages to avoid structural breakage, have been investigated and developed 4.An adapted sensors deployment strategy for cost-efficient structural health monitoring of complex flexible marine infrastructures has been developed. This strategy is based on the deployment of a combination of wireless sensors like accelerometer, depth sensors and load cells installed in critical locations on the structure.

Dette prosjektet har flere resultater som hovedsakelig er relatert til fire emner: Sanntidssimulering av komplekse fleksible merder med skjermingsteknologi, prediksjon av kortsiktige og langsiktige effekter av organismer som vokser på not, strukturell helseovervåkning (SHM) og plasseringen av tilstrekkelig sensornettverk på et havbruksanlegg for å overvåke og forutsi eventuelle uønskede hendelser. En nytteverdi fra prosjektet er at sanntidssimuleringene av merdene og prediksjon med fem dagers værmelding vil tillate utstyrsleverandører og oppdrettere til å utvikle skreddersydde merder med et skjermingsteknologidesign. I tillegg vil teknologiutviklingen rundt overvåking og inspeksjon kunne dra nytte av disse resultatene. Vurdert løsningene gir et omfattende datagrunnlag som er nødvendig for å flytte havbrukssektoren mot en mer digitalisert fremtid,noe som muliggjøres gjennom sensorsystemer. Brukergruppen er forvaltning og oppdrettere og utstyrsleverandører og bedrifter fra IT sektor

As the aquaculture industry continues to expand, fish farm operators are looking to adopt new technologies to ensure that the quality of fish cultivation reaches the highest standards and production efficiency is maximised. The FlexAqua project will address the key knowledge gaps related to the growing use of new shielding solutions, to prevent parasites infestation. These shielding technologies are of two types: parasites-barrier skirt and snorkel cages. The project will generate knowledge to prevent breakdown of these new farming systems which could lead to fish escapees. Parameters like sea states (currents and waves) and effect of marine organisms will be investigated. A novel Fluid-Structure Interaction (FSI) analysis will be carry out on these flexible structures to predict hydrodynamic loading and structural behaviour under a range of sea states, which is of growing interest as aquaculture production extends to high-energy sites and so towards under severe environmental loading for structures. The effect of marine growth colonisation on the forces acting on these farming systems will be explored by using novel 3D imaging techniques and which will be used to develop more accurate and realistic FSI setups. New image processing techniques will be developed for detecting and monitoring damages such as corrosion, cracks and net defects. Finally, an adapted sensors deployment strategy will be devised for cost efficient structural health monitoring of these complex flexible marine infrastructures. Overall, this project will shed light on the long-term performance of these new shielding designs under various sea conditions and will develop effective monitoring strategies and damage detection techniques to help ensure structural integrity is maintained during the in-service life of these structures