Smoltsimulator
Based on earlier work with sentinal cages we have developed a new method to estimate the lice burden from infectious stages of salmon lice. The method is a mobile version of the sentinel cage, where knowledge on the migration route, speed and residents time of the smolt in the locks or fjords can be applied. A preliminary name of the method is “smoltsimulator” as it attempts to simulate the smolt run.
The smoltsimulator will be kept in the upper few meters of the water column, since the likelihood of encounter with salmon lice copepodids is higher in surface waters (Huse & Holm 1993, Heuch et al 1995, Penston et al 2008). The depth at which the copepodids are most abundant may vary with salinity, as salinities <20 psu have been shown to compromise copepodid survival (Bricknell et al 2006) and copepodids may aggregate at salinity gradient boundaries (Heuch 1995).
It is necessary to use a camera to film the fish in the cage, as this will be an important tool to adjust the speed of the haul according to the swimming behavior of the fish. In addition this could possibly be used to identify specific behavior that can be associated with salmon lice encounter.
This field season we will need to assess how hard the cage is to handle and the feasibility of fish stocking and removal during the haul.
The work is labour intensive and can only be conducted in certain period of the years when fish is avialble as salmon smolt from cultivation hatcheries.
The smoltsimulator will be kept in the upper few meters of the water column, since the likelihood of encounter with salmon lice copepodids is higher in surface waters (Huse & Holm 1993, Heuch et al 1995, Penston et al 2008). The depth at which the copepodids are most abundant may vary with salinity, as salinities <20 psu have been shown to compromise copepodid survival (Bricknell et al 2006) and copepodids may aggregate at salinity gradient boundaries (Heuch 1995).
It is necessary to use a camera to film the fish in the cage, as this will be an important tool to adjust the speed of the haul according to the swimming behavior of the fish. In addition this could possibly be used to identify specific behavior that can be associated with salmon lice encounter.
This field season we will need to assess how hard the cage is to handle and the feasibility of fish stocking and removal during the haul.
The work is labour intensive and can only be conducted in certain period of the years when fish is avialble as salmon smolt from cultivation hatcheries.