Estimating purse seine volume during capture: implications for fish densities and survival of released unwanted catches

High fish densities negatively impact catch welfare and the survival of unwanted catches released from purse seines. To avoid overcrowding fish before being released, regulations have been implemented in the Northeast Atlantic mackerel and herring fisheries that limit the proportion of the seine that can be retrieved before catches are released. However, it is yet unknown how seine volume, and thus fish density, relates to proportion of seine...