Micro-particles in recirculating aquaculture systems: particle size analysis of culture water from a commercial Atlantic salmon site

摘要

As part of a larger study of micro-particles in a recirculating, cold water aquaculture system for juvenile Atlantic salmon (Salmo salar), particle size analyses were carried Out on the culture and makeup waters over several months followed by samples of feed stirred in water. The particle size distributions followed the power law described in [Aquacult. Eng. 19 (1999): 259] but with a superimposed spike at around 4 pm in the culture water, which was not present in make-up waters. A similar spike appeared in the feed samples indicating that the spike had a feed origin. While the absolute value of the power law exponent (designated beta, or the Beta value) was in the range of 2.6-3.6, consistent with aquacultural waters, the build-up of fine particles, expected in a recirculating system with time and which would have been indicated by an increase in Beta value to above 4, did not occur due to a system high water turn-over rate flushing much of the finer particles. There is a particle counts increase occurring across the degasser/oxygenator that needs further investigation.