The SASI, Shellfish Associated Species Inventory is part of the SIMP, Shellfish Import Monitoring Protocol. The purpose of this inventory is to get more information about the species, and in particular the invasive alien species which can accidentally be imported with the shellfish into the Netherlands. This method of sampling is suitable for macro flora and macrofauna > 1 mm.

During a SASI multiple samples are taken spread throughout the production area. In each sample of approximately 5kg shellfish, all animal and algal species that live between the sampled shellfish are scored. For each species found during the surveys, it is determined if the species is a nuisance species. Each research area should be searched until it is expected that with a double amount of samples, no more than one species should be found. With this method, the total diversity in an area can be estimated on the basis of an accumulation curve, a widely used reliable scientific method to capture the total diversity of species in a field.