SURVIVAL AND CHELIPED LOSS OF JUVENILE LOBSTERS HOMARUS-GAMMARUS DURING SIMULATED OUT-OF-WATER TRANSPORT

Juvenile lobsters Homarus gammarus reared for stock enhancement progra ms are frequently packed in Styrofoam boxes between layers of wet news paper and shellsand and transported out of water from hatcheries to re lease sites. A single layer of frozen newspaper acts as a cooling elem ent. The physical disturbance experienced by individuals while being t ransported was simulated under controlled conditions. Juveniles were s ent on ''journeys'' lasting 0, 6, 9, 12, 15, 18, 21, and 24 h and were physically disturbed for 15 min of each hour. Mortality was low (2-7% ) within the first 12 h of simulated transport but increased significa ntly (12-22%) after 15 h of exposure. This increase was primarily a re sult of high mortality (21-45%) in individuals packed in the layer nea rest the cooling element. Air temperature recordings revealed a temper ature gradient between layers throughout the test period. In all, 68.5 % of all observed mortality occurred within 6 h of juveniles being ret urned to ambient seawater. Overall, 41 of the 80 animals identified as newly molted had died 72 h after the simulation. Cheliped loss was lo w (4.3%), but it did increase significantly with increased length of t he simulated transport period. The results indicate that out-of-water transport is cost-effective for journey durations up to 15 h, but for longer periods the use of frozen newspaper as a cooling element requir es careful examination. It is suggested that damp tissue paper is more suitable for the purpose. Out-of-water transportation of newly molted animals is not advised.