A simple and efficient cooling method for post-harvest transport of the commercial crayfish catch

Factors affecting post-harvest survival were investigated for the signal crayfish, Pacifastacus leniusculus (Dana), catch during onboard transport and subsequent holding at a land storage facility. Based on those results, an onboard transport method was developed. The research and development project was carried out during July, August and September 2010 - 2011 on Lake Saimaa, Finland. The investigation showed that critical factors for survival were air temperature during onboard transport and water temperature during trapping of signal crayfish. To minimise onboard transport stress caused by the elevated temperature and resulting decrease in survival, several transport methods were tested. The commercial catch of signal crayfish was monitored over an entire day and a newly developed, rapid cooling method was compared to existing conventional onboard cooling systems used during transport. When the crayfish catch was rapidly cooled from ambient temperature (20 - 26°C) to 5 - 7°C, it resulted in 100% survival of the crayfish during transport. The improvement in catch survival was estimated at 10%, compared to the conventional transport methods when the holding facility mortality was taken into account. The improved cooling system during boat transport consisted of cooler boxes equipped with -20°C cooling units on the bottom, a mesh to prevent crayfish from being in contact with frozen material and a plastic bag to ensure a cool and moist environment during onboard and road transport. Copyright © 2013 International Association of Astacology