Application of new technology and innovative approaches in monitoring fish welfare of Atlantic Salmon

Følgende mål var planlagt dokumentert under prosjektet i perioden 2018 - 2023: 1. Dokumentasjon av smartTag-teknologi for kontinuerlig overvåking av fiskens velferd 2. Å dokumentere at SmartTag ikke har negative effekter på fiskevelferden. 3. Dokumentasjon av pågående kommersialisering av SmartTags og 4. Styrke FoU-kapasiteten innen selskapet; «Organic Seafood» (tidligere Seafood Sceurity). Resultatene viste at i storskala produksjonsenheter at effekten av interne akustiske merker påvirket signifikant på tekstur og filétkvalitet, men det var ingen effekter på vekst eller filét innfarging. Det var også lav gjenvinningsgrad av merkene på slaktelinjen (fra 50 % til 78 % av merket fisk ble identifisert), og vi anbefaler mer pålitelig identifikasjon av fisk med smartTags. SmartTag-effekt på fiskevelferd ble dokumentert i to separate forsøk. Resultatene viste at merking av tidligere ustresset fisk i et kontrollert miljø ikke påvirker velferden negativt når det gjelder stressreaksjoner. Videre viste det seg at stress forsinker sårheling og øker den inflammatoriske responsen, og fremhever hvordan fortsatt stress forårsaker sammenbrudd i enkelte stressresponser. Til syvende og sist kan merking av atlantisk laks lykkes under forhold hvor fisk er i god form og kronisk stress ikke er tilstede. Flere forbedringer på SmartTag-en har blitt iverksatt som bedre respons, forbedret akustisk rekkevidde og forlenget batterilevetid. En prototype av smartTag er nå klar for endelig testing, og forventes ferdigstilt i slutten av 2025. PhD-kandidat Miiro Ilimari Virtanen er i sluttfasen av sin doktorgradsavhandling. Han forventes å levere ph.d.-avhandlingen i midten av juni 2023, med avsluttende disputas i midten av september 2023. Deretter går han over i en seniorforskerstilling i selskapet for å sikre ferdigstillelse av smartTag-teknologien.

Outcomes: 1. Documentation of smartTag as a technology for on-site in-fish monitoring of fish welfare The effect of intraperitoneal acoustic dummy tags on texture and gaping was significant, but there were no effects on growth or fillet colouration. 10 % of the ADT was attached to the belly flap, and there is a need to research further to examine how this could be avoided. There was also low retention rate (from 50% to 78 % of tagged fish was identified), and we recommend more reliable identification of fish with ADT. Frequency of melanin spots were higher in ADT group in cage 2, but more research is needed to conclude on the reason. Gaping and texture was varying in an unsystematic way, and more research is needed to conclude on the effect of tagging on gaping and texture. 2. To document that the SmartTag has no negative effects on fish welfare The wound healing process showed that stressed fish have a larger and longer-lasting inflammation period and a slower wound healing process, as seen from the inside wound. The tagging of Atlantic salmon did not cause chronic stress. In contrast, daily stress led to an allostatic overload type two response. ACTH was elevated in the plasma after four weeks, and cortisol followed elevation after six weeks, highlighting a breakdown of the stress response. Fin erosion was elevated alongside cortisol increase in the stressed group. This data suggests that tagging previously unstressed fish in a controlled environment does not negatively affect welfare regarding stress responses. It also indicates that stress delays wound healing and increases the inflammatory response, highlighting how continued stress causes a breakdown in some stress responses. Ultimately, the tagging of Atlantic salmon can be successful under certain conditions where proper healing is observed, tag retention is high, and chronic stress is not present, which allows for the possible measurement of welfare indicators. 3. Documentation of proof of concept for commercialisation of SmartTags On-going, planned to be finalised late 2025 4. Strengthen the R&D capacity in Seafood security After Miiro I Virtanen submission of PhD thesis in mid-June 2023, will he be going over in a senior researcher position at the company to complete the SmartTag development

Growth of the aquaculture industry in Norway will only permitted with implementation of novel technology reducing the risk of escapees and/ or that put more emphasis on fish welfare. Number of escaped fish was reduced from 921 000 fish in 2006 to 20 000 in 2017, but varies from year to another. As much as 40% of the escapees has unknown causes, and may indicate that the farmers have too little control. Surveillance technology is needed to improve control with fish in the pens and to reduce number of escapees. Another key challenge for the salmon industry is the unacceptable high mortality rates during on-growth in sea. Losses during on- growth is used as a welfare indicator for fish welfare and summed up to 53 million fish in 2016 and 2017 (Fiskehelserapporten 2018). Mortality is however, not a good measure on fish welfare. Fish welfare is defined as “the quality of life as perceived by the animal itself”. Securing good welfare is of key importance in commercial farming of Atlantic salmon and is central for key decision’s farmers take during their daily husbandry practices and longer-term production planning. Salmon producers are seeking solutions to optimise fish welfare and actively employ strategies to minimise fish welfare threats. Welfare Indicators (WI) are used to assess the overall welfare status of the fish. The WIs that can be used on-site are termed Operational Welfare Indicators (OWIs). Other WIs have to be determined by specialised laboratories and are termed Remote Off-farm Welfare Indicators (ROWIs). There is an urgent need to develop technology facilitating a more direct communication with the salmon in commercial production. The aim of this project is to test and document novel technology for measuring fish welfare, biomass control and escapees.