Toward Species-specific Catch and Cpue Time Series for Sharks Caught by the Japanese Longline Fishery in the Atlantic Ocean

This document introduces problems associated with shark catch data and CPUE indices using the Japanese longline fishery in the Atlantic as an example. A number of methods for addressing issues of under-reporting, short time series, and undifferentiated shark species are introduced including reporting rate filtering, comparison to observer datasets, covariate analysis, meta-analysis and tradebased methods. It is argued that status quo analytical techniques will not be sufficient to advance the state of shark databases to the necessary quality for robust stock assessment and that new forms of cooperative analysis are likely to be required.