Towards sustainable mud crab (Scylla serrata Forskål, 1775) aquaculture and fisheries through hatchery optimisation and adaptive management frameworks

Abstract

The recent expansion of farming and increasing seafood demand have heightened pressure on mud crab (Scylla serrata) populations across the Indo-Pacific. This PhD thesis promotes sustainable mud crab aquaculture and fisheries management by integrating hatchery optimisation, nursery decision tools, and adaptive fishery modelling. Semi-commercial hatchery trials demonstrated that “green-water by design”, using selected microalgal products as background algae, enhances larval survival, synchronises metamorphosis, and establishes a reliable harvest window immediately after peak megalopa appearance. A complementary Artemia enrichment experiment indicated that HUFA and other feed additives offers limited benefit under typical hatchery conditions, highlighting the greater influence of developmental timing and husbandry.

Nursery stocking density trials (125–1000 crablets m⁻²) showed clear trade-offs between growth and survival, with the best performance at low to moderate densities. These findings contributed to the development of a composite readiness index (CARS15), which integrates survival, size, injury, uniformity, and moulting risk to support harvest and stocking decisions.

Finally, a data-limited bioeconomic model applied to the Ngeremeduu Bay mud crab fishery (Palau) shows that moderate effort reduction and higher minimum size limits can improve biomass and profitability without restocking. Collectively, these methods offer practical, scalable options for enhancing seed supply, supporting aquaculture growth, and strengthening the resilience of the mud crab fishery across the Indo-Pacific.

Date of Award	30 Jun 2026
Original language	English
Awarding Institution	University of St Andrews
Supervisor	Mark James (Supervisor), Neil Hazon (Supervisor) & Tania Mendo (Supervisor)