Training workshop proceedings: adaptive co-management of fisheries (January 21-25, Boyboison Lodge, Fijai, Ghana)

The Adaptive Collaborative Management of Fisheries Training workshop was held in Sekondi, Western Region of Ghana as part of the project “Integrated Coastal and Fisheries Governance Initiative” locally referred to as “H n Mpoano”. The aim of the project is to support the government of Ghana achieve its development objective of poverty reduction, food security, sustainable fisheries management and biodiversity conservation and contributes to its vision: Ghana’s coastal and marine ecosystems are sustainably managed to provide goods and services that generate long-term socioeconomic benefit to communities while sustaining biodiversity.

The use of agreement measures and latent class models to assess the reliability of classifying thermally marked otoliths

Otolith thermal marking is an efficient method for mass marking hatchery-reared salmon and can be used to estimate the proportion of hatchery fish captured in a mixed-stock fishery. Accuracy of the thermal pattern classification depends on the prominence of the pattern, the methods used to prepare and view the patterns, and the training and experience of the personnel who determine the presence or absence of a particular pattern. Estimating accuracy rates is problematic when no secondary marking is available and no error-free standards exist. Agreement measures, such as kappa (κ), provide a relative measure of the reliability of the determinations when independent readings by two readers are available, but the magnitude of κ can be influenced by the proportion of marked fish. If a third reader is used or if two or more groups of paired readings are examined, latent class models can provide estimates of the error rates of each reader. Applications of κ and latent class models are illustrated by a program providing contribution estimates of hatchery-reared chum and sockeye salmon in Southeast Alaska.