Estimating sea lice infestation pressure on salmon farms: Comparing different methods using multivariate state-space models.

•Different methods to estimating sea lice infestation pressure on aquaculture farms were compared using a state-space model.•Models with only EIP explained the variation in the data better than models with only IIP.•Models with unique IIP and unique EIP for all cycles were generally associated with the best model fit.•The fixed lag method for calculating infestation pressure had the best predictive performance among the methods studied.•Aquaculture farms in Grand Manan area were exposed to similar sea lice infestation pressures.