North Pacific armorhead (Pseudopentaceros wheeleri) is a main target species of trawl fisheries at Emperor Seamount Chain located northwest of Hawaiian Islands, and have been required to conduct stock assessment for applicable management of fishery resource and sustainable fishing. This fish has unique life history traits; spend a larva-juvenile term at an epipelagic zone of the open ocean, and then settle and reproduce at sub-bottom of the seamounts. Mass settlement of adult armorhead happens once in many years. These ecological traits cause the difficulty of stock analysis with conventional fishery stock assessment models. Furthermore, huge cost is needed for stock survey with a research vessel because the seamount habitats are a long way off from Japan. To help future forecast of stock condition and applicable management for sustainable use, we estimated the fluctuation of stock biomass and population dynamics parameters by using the spatial state model with catch amount presumed as huge time series observed data containing uncertainty.

The spatial-state model was composed of two components, separating biological process error in the stock dynamics from observation error. The parameters estimated by MCMC with catch amount of armorhead harvested from trawl fishery at the Emperor Seamounts from 1992 to 2010 showed that spatial growth rate and fishing pressure tend to spatially synchronize among seamounts.