EFFECTS OF AIR EMERSION ON SURVIVAL AND GROWTH OF HATCHERY REARED GREAT SCALLOP SPAT

G. Christophersen-2000
Aquaculture International, 8 (2/3): 159-168
Abstract:
Scallop spat production normally requires transfer between growth systems. Simulated transport experiments were carried out in April, June, December and February to evaluate effects of transport time on great scallop (Pecten maximus) spat growth and survival. The spat (1.7-1.8 mm in shell-height and 21-25 µg ash free dry weight [AFDW]) were held in moist coffee filters at a temperature of 10 °C for up to 24 h, before being replaced into sieves in rearing tanks at 15 °C. The study showed that by increasing air emersion time, survival and growth decreased. No significant difference in the results between 0 and 4 h of air emersion was found, while the effects after 12 and 24 h differed between spat groups. Survival and growth rates showed seasonal differences. Mean survival was 35-71% in April and 77-99% from June to February. In June mean growth rates attained were 115-128 µm shell-height and 15-18 µg AFDW per day compared with 49-69 µm and 3.8-7.0 µg per day for the other spat groups. Great scallop spat may survive a transfer time of 24 h, but transportation for longer than 12 h is not recommended if subsequent high survival and growth rates are to be ensured.

(Centre for Studies of Environment and Resources, University of Bergen, Bergen High-Technology Centre, N-5020 Bergen, Norway, E-mail: gyda.christophersen@smr.uib.no)

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