This project identified several factors that influence permanent attachment of the purple-hinge rock scallop (Crassadoma gigantea). From these findings the following recommendations for cost-effective and efficient grow-out methods were developed: (1) permanent attachment should be promoted, as unattached scallops grow more slowly; (2) flat PVC plastic or similar substrates should be used over cement or ceramic substrates in order to minimize damage to animals and gear during harvesting; (3) plastic or similar smooth substrates should be roughened prior to use to increase attachment strength, thereby minimizing unintended dislodgement of animals during grow-out; (4) scallops should be artificially attached (e.g., glued) to substrates prior to grow-out to allow use of any size seed scallop and to provide a means for manipulating attachment location and optimizing spatial distribution.