Forsøksdyr: Pre-trial testing of novel heart rate monitoring tags on the decapods king crab (Paralithodes camtschaticus), snow crab (Chionoecetes opilio) and Atlantic salmon (Salmo salar)

Godkjenningsdato 09.11.2018

The aim of the experiment is to demonstrate the efficacy of a novel heart rate monitor (DST micro-HRT, Star Oddi, Iceland) for measuring stress and metabolism in crustacea and finfish. In this pre-trial two species of crab will be used as well as Atlantic salmon.

The live holding and transport of king crab both within Norway and for live export is increasing. Snow crab is becoming a candidate for the same. There is limited knowledge and a paucity of relevant literature regarding the measurement of stress in crustaceans. Nofima have developed a non-intrusive vitality index for crustaceans but this does not allow for real time measurements during transport. A heart rate monitor that is flexible and independent would be a valuable tool for measuring the metabolism of crustacea during transport and in live holding facilities.

Impaired cardiac function of Atlantic salmon is a debated problem in aquaculture research since mortalities are frequently linked to a weakened cardiovascular system of fish in aquacultures. Increased stress may be a main factor for this impairment; however, suitable methods to examine this connection are limited. Implanted heart rate monitors are a promising tool to gain insights into the heart function of a living animal and therefore for evaluation of stress level, effects of know stressors and identification of unknown stressors.

As this is a pre-trial, a limited number of animals will be used to test the efficacy of the tag and the ability to implant the tag into the animals with minimal stress and mortality. 8 King crab, 8 Snow crab and 8 Salmon will be tagged. In addition, 62 Salmon will be used to maintain a normal (current) biomass in the rearing tank. These 62 will not be tagged or treated in any way.

The experimental crabs will have a 2.5cm (8mm diameter) heart monitor tag hereafter referred to as HR-tag attached to the top of the carapace. Where the tag is attached the outer carapace layer will be removed to expose the underlying dermis above the heart. This area will be kept to a minimum and will be approximately 30mm x 10mm, enough to accommodate the tag. The procedure may cause some discomfort for the crabs. The experimental salmon will have the same HR-tags inserted into the abdominal cavity by means of a small incision that is sutured close after insertion. The surgical procedure is the reason for the classification “belastende”.

In order to accurately access the efficacy of the tags it is necessary to expose animals to moderate level of stress when the tag is implanted and to document the effect this procedure has on animal welfare. We will be using the minimum number of replicates that will give an accurate and meaningful results. The management of the experiment (e.g. humane end points, qualified staff experienced in handling, operating and tagging, experimental animals) will ensure that the distress experienced by experimental animals will be kept to a minimum.