ABSTRACT Summer seed mortality (SSM) has occurred yearly in Tomales Bay, California since 1993. SSM has resulted in up to 90% cumulative losses, and has been associated with extreme temperature, phytoplankton blooms, and an oyster herpesvirus. In this study, three stocks of Pacific oysters were planted at three sites in California (Inner Tomales Bay, Outer Tomales Bay, and Bodega Harbor) in October of 2000 (Fall) and April of 2001 (Spring) and monitored for mortality, growth, and ...
<0.05, r = 0.916). Growth rate and cumulative mortality were not significantly correlated at the Outer Bay (P><0.05) and was similar between the Outer Bay site and Torten Inlet (P><0.05). The first temperature maximum over 24[degrees]C occurred 15 days before losses of up to 50% at the Inner Bay site (Fig. 6). Immediately prior to oyster losses, during the period of May 19 to June 8, all sites had a temperature maximum exceeding 24[degrees]C (Fig. 5), however oysters grown at the Inner Bay site experienced several temperature maximums of>