Effect of different longline farming designs over the growth of Mytilus chilensis (Hupé, 1854) at Llico Bay, VIII Región of Bio-Bio, Chile

Abstract

This study evaluates the effect of three culture design factors over the growth of the Mylitus chilensis, farmed through suspended systems known as longline with buoys, and longline with High Density Polyethylene (HDPE) tubes. The study was carried out at the Llico Bay, VIII Region of Bio-Bio, Chile. The three factors studied are: sleeve spacing, sleeve type and depth. The results show that in the longline with buoy system, the sleeve spacing presented a significant effect over the shell length and the wet meat weight (p<0.001, for both growth variables). On the longline of HDPE tubes system, the sleeve spacing had a significant effect over the meat yield (p<0.001). The depth factor had the most important effect over the growth on the longline with HDPE tubes system (p<0.001). The sleeve type presented an effect on all growth variables (p<0.001), but only in the longline of HDPE tubes. The conclusion is that on the longline with buoys, for M. chilensis farming, the best growth results and operational advantages are obtained under the following design configuration: continuous sleeve with spacing between sleeves of 40cm, and a length/depth of 6m. For the longline with HDPE tubes, the best configuration is a net sleeve, with gaps of 40cm and a length of 6m. When comparing results by both types of longline in a semi exposed zone, at the end of the study period, the longline of HDPE tubes shows superior results in shell length and meat yield over the longline of buoys with an 8.13% increase in the shell length and a 7.22% in meat yield.