Stocking density and rearing environment affect external condition, gonad quantity and gonad grade in onshore sea urchin roe enhancement aquaculture

Abstract

Finding the ideal density to optimise growth, health and welfare of aquaculture species reared in cage or tank environments allows farmers to produce the best quality product per unit area. Appropriate stocking densities are well known for most major aquaculture species, but limited information exists for the developing sea urchin aquaculture industry. The temperate purple sea urchin Heliocidaris erythrogramma is a prime candidate for aquaculture, yet how stocking density and/or the rearing environment influence urchin health and roe production remain unknown. Here, we tested whether stocking density (low vs. high) and rearing environment (individual vs. group) influences urchin external con..