Harvest control rules (HCRs) for sustainable fishery management have been developed for data-limited fish species for which stock assessments cannot be conducted. However, HCRs have largely not considered mixed-species catches, as when fishing-effort data are widely pooled for numerous minor species in a multispecies fishery. Presently, a feedback HCR has been successfully applied in Japanese fisheries management. By combining management strategy evaluation with a simulation to generate mixed-species data from a multispecies fishery that assume constant catchability (q) among species, we evaluated the performance of this feedback HCR and then compared its performance using species-specific data. In most cases, the biomass was controlled over that needed for maximum sustainable yield (MSY), and the fishing effort was under the fishing mortality consistent with achieving MSY (FMSY). However, for slow-growing species, the biomass might become lower than what is required to remain capable of producing MSY, even though fishing effort was controlled under FMSY. The results show that the feedback HCR is appropriate for multispecies fisheries management where only mixed-species data are available but with special monitoring for slow-growing minor species.

Malaysian fisheries employ multiple measures to improve management; however, not all are well‐suited to the multispecies fisheries. As part of a pilot project, an individual quota system was introduced for the purse‐seine fishery off the East Coast of Peninsular Malaysia (ECPM), but no assessment of this particular measure nor the feasibly of its implementation has been confirmed. Therefore, this study analysed spatial and temporal patterns of purse‐seine fishing, by collecting catch composition data per landing and its fishing ground within three period fishery surveys between August 2017 and September 2018 at six different landing sites. Similarity and cluster analysis examined species composition and diversity to determine the feasibility of implementing a single‐species quota system in this multispecies fishery. Some overlapped of indices results and minor difference in catch composition were found due to changes in spatial and temporal fishing activities. However, no specific spatial or temporal patterns were discernible as structuring the fishing grounds used by purse‐seiners. The absence of patterns, using the available data, might be attributable to huge species aggregations and widely distributed and homogenously mixed fish stocks. Thus, it is likely impractical to manage species individually in such a multispecies fishery.

Cakalang (Katsuwonus pelamis) is one of the leading export commodities landed at the Prigi Fishing Port (PPN Prigi). Skipjack tuna fisheries management conducted the conventional single-species Schaefer model which is often applied although it is not technically suitable for multispecies fishery. The application of feedback harvest control rule (HCR) is an alternative harvest strategy that has been successfully implemented and validated for multispecies fishery. This study estimated allowable biological catch by applying two harvest strategies, HCR feedback and Schaefer surplus production model using catch-effort data of skipjack tuna landed at PPN Prigi in the period 2010 - 2019. Model Schaefer pointed out that catches have exceeded the maximum sustainable yield () even employed low the fishing effort which was under the fishing mortality consistent with achieving MSY (). The application of feedback HCR that has been previously validated can be an alternative of harvest strategy for use in fisheries where only mixed species data is available. Key words: multispecies fishery, harvest strategy, Schaefer model, maximum sustainable yield, single-species approach