The Molluscan Broodstock Program (MBP) has been breeding Crassostrea gigas since 1996, and oyster growers across the California Current use its primary “Miyagi” lineage extensively. Recently, the MBP imported a new lineage of C. gigas from Southern Japan (the “Midori”) for its potential resilience to thermal stress and disease. The introduction of the Midori lineage has garnered significant interest from industry members seeking to enhance their operations using this more robust lineage. This has led to wide-spread cultivation of the Midori lineage; however, few studies have sought to directly compare seed performance of the two lineages at large multi-estuary scales. Here we report on a series of farm trials in Yaquina Bay , OR; Humboldt Bay, CA; Tomales Bay, CA; and Morro Bay, CA. Our findings highlight the increased robustness of the Midori lineages when reared in stable SEAPA type oyster gear. These findings however do not hold when oysters are raised in tipping gear where mortality rates between lineages was not significantly different. Together our data provide a broad evaluation of the new Midori lineage of C.gigas and provides insights into how each lineage responds in key characteristics (survival, shell shape, meat weight) across a broad geographic region.