Viability of a bottom‐set tray ocean nursery system for Holothuria scabra Jaeger 1833

Scaling up the hatchery production of juvenile sandfish Holothuria scabra is constrained by limited hatchery space and the associated high operational costs. To shorten the hatchery rearing phase, ocean nursery systems like floating hapa nets have been used with good prospects but with limitations during rough sea conditions. In this study, the potential of bottom‐set trays (0.14 m2) as an alternative ocean nursery system for early sandfish juveniles (0.5 ± 0.1 cm) was evaluated. The effects of stocking density and presence of artificial substrates (AS) on the growth and survival were determined in a 60‐day field experiment. Average length and growth rates at lower stocking density treatment (100 individuals tray−1) were significantly higher (1.45 ± 0.22 cm; 0.03 ± 0.01 cm day−1) than at higher stocking density treatments (400 and 500 individuals tray−1) 0.95 ± 0.06 cm; 0.03 ± 0.004 cm day−1) with or without AS (p