Operational procedures for treatment of the salmon parasite Gyrodactylus salaris by use of the AlS method

Summary

This report is based on a number of operational procedures for treatment of the salmon parasite Gyrodactylus salaris by use of the AlS method. The procedures are attached, and the report itself is a chronologically based review which refers to the procedures where appropriate. The term AlS has been used by NIVA for a set of commercially available or specially produced chemicals used for treatment. These are sulphuric acid and different kinds of aluminium sulphates. In specific areas with stagnant waters and seeps this treatment is supplemented by use of CFT-Legumin (rotenone). In complicated hydrological areas where groundwater meets river water, supplementary methods may also be used. When used for eradication of the parasite, the AlS method is based on treatment over two consecutive years of all water bodies where the Atlantic salmon can live. The treatment each year is based on 14 days of effective treatment, followed by a pause of two weeks, and then a new period of 14 days of effective treatment. The treatment is thus dependent on good organization and adequate planning. Dosing equipment for small streams, medium sized streams and large rivers is used. Procedures have been developed for both administrative and technical issues. i.e. the setup, operation and dismantling of dosing plants. The field manager (FM; FA from “feltansvarlig” in Norwegian) is a key person on site. The FM has to follow the consumption of chemicals at all sites and examine precipitation forecasts for possible changes in water flow and thereby changes in consumption rate. The FM orders re-filling and ensures proper distribution of chemicals to the respective storage tanks. One procedure is therefore dedicated to the tasks and responsibilities of the FM. Experience have shown that two FMs with different responsibilities are needed during treatment. Demanding field work makes people get tired, and during dismantling and clearance of the dosing sites after treatment the danger of chemical spills and splash is increased. This may also be due to chemicals under pressure at some sites. The procedures for these operations therefore have an especially high focus on operation routines and health, safety and environment (HSE). The AlS method has been developed over several years (2003-2014). On further use of the method these procedures should be improved and new should probably be added.