Management issues and options for small scale holobenthic octopus fisheries

Octopuses are a difficult resource to manage due to their short life span, rapid growth, high natural mortality and sensitivity to environmental conditions. These biological traits result in seasonal fluctuations in abundance and subsequent landings. Twenty two octopus fisheries were reviewed from 17 countries to examine the application and effectiveness of different management measures for consideration in the Tasmanian Octopus pallidus fishery in Australia. While the most commonly used measures in these fisheries were input controls, particularly seasonal closures and minimum size limits, these controls are poorly suited to semelparous, holobenthic octopuses such as Octopus pallidus. A semelparous reproductive strategy means that minimum size limits don't allow animals to reproduce prior to capture. A holobenthic life history strategy means that fishery-wide seasonal closures are unable to address variation in biological characteristics (e.g. size at maturity) across sub-stocks and collectively reduce effort on vulnerable life stages. Seasonal closures and minimum size limits also reduce the economic efficiency of the fleet and may diminish fishery productivity through effort displacement and serial depletion. A rotational system of effort or cap on total effort that provides flexibility to fishers and effectively spreads fishing effort, allowing different areas or sub-stocks to recover, could be a more effective option for achieving the objectives of most octopus fisheries.