Depuration conditions for great scallops (Pecten maximus)

摘要

Trials were undertaken to determine appropriate conditions for depurating hand-gathered great scallops (Pecten maximus). Scallops were contaminated with Escherichia coli to levels consistent with those requiring deputation by relaying in sewage impacted waters for a minimum of 2 weeks. These scallops were then purified for 42-48 h in both laboratory and small-scale commercial deputation systems under varying conditions. Levels of E. coli were monitored before and after depuration to assess the effect of temperature, salinity, shellfish-loading arrangements, and the use of artificial seawater on the deputation process. Self-righting trials were used to assess the amount of stress imposed on the scallops caused by transport, handling, and the deputation procedures. Results to date demonstrate that the use of artificial seawater cannot be recommended. During depuration, natural seawater should be maintained at a salinity greater than or equal to30parts per thousand and at a temperature greater than or equal to10degreesC. Our results demonstrate that scallops could be depurated in a double layer within trays at a nominal density of 250 scallops m(-2) with a shellfish-to-water ratio of 1: 12 (kg:L).