Per-recruit modelling of pulse fisheries: comment on Modelling pulse fishery systems in data-limited situations

A pulse fishery is one where fishing occurs during a short period each year and is zero for the rest of the year. Gruss et al. proposed a continuous per-recruit model for such fisheries. However, this analysis is based on per-recruit equations that were derived under the assumption that fishing mortality is constant in time and, thus, do not apply to fisheries where F varies, such as a pulse fishery. A correct continuous per-recruit formulation for pulse fisheries is derived. In most cases, the continuous per-recruit model can be closely approximated by a discrete model, where the integrals are replaced by sums. A modification in the Baranov catch equation for pulse fisheries is also derived that can used to compute annual exploitation rates.

Automated summary

The article discusses the continuous per-recruit model for pulse fisheries and points out the issue that the existing model does not apply to fisheries with varying fishing mortality rates. A correct continuous per-recruit formulation for pulse fisheries is derived. In practice, the continuous per-recruit model can usually be closely approximated by a discrete model for calculating annual exploitation rates.