Since the inception of fisheries assessments, fisheries scientists, stock assessors, marine ecologists, statisticians, and others have contributed to the development of intricate stock assessment models. These are the cornerstone of fisheries resource management, giving scientific advice through harvest control rules and proposal of catch limits. While attention has focused on developing and improving the models, the concepts upon which these are founded are reliant on many of the base assumptions, estimates, and methods derived:
- natural mortality
- maturity and fecundity
- catch estimates, landings and discards
- catchability and selectivity
- growth
- recruitment and the stock - recruitment relationship – the corner stone of stock assessment
- Maximum Sustainable Yield
This theme session aims to review the recent developments in the concepts above and new emerging issues being incorporated into assessments, such as:
- handling of missing data
- estimation of commercial and survey indices
- handling of “plus" age groups
- reference point estimation
- density dependence
- regime shifts
- spatial aspects and stock ID
- migration
- rorecasts for advice
- best practice in diagnostics, model validation and weighting
This session is open to presentations on recent, applicable developments in the historic fundamental bases of stock assessments – such as surplus production, statistical catch at age, state-space and integrated models – and improvements in the model, forecast & advice information flow.
The conveners welcome explorations of quality control and extensions to spatial aspects of stock ID, spatial shifts and migration. We also invite examples of bridging the gap between single-species stock assessment and ecosystem-based fisheries management in provision of advice to functionally incorporate ecosystem information.
This is a broad subject area, and the theme session will focus on new developments that are mature enough to consider their implementation in the fisheries assessment process.