We study the adaptive harvest of healthy stocks of shellfish that are faced with the risk of high natural mortality from a disease that is spreading along a coastline. This was the situation when Abalone Viral Ganglioneuritis (AVG) spread along the coast of Victoria, Australia in 2006. Abalone mortality on some reefs was thought to have been as high as 90%. In the face of an approaching virus, how should stocks at different reefs be managed? A stochastic, spatial bioeconomic model allows us to examine how optimal preemptive stock reductions are influenced by: (1) the probability of spread, (2) the mortality induced by AVG when it reaches a previously uninfected reef, (3) the form of the harvest cost function, and (4) a regime shift to lower biological productivity, post-AVG.

JEL Codes: Q2, Q22.