Behavioural Characteristics of Scomber japonicus in the Sea Cage with Acoustic Telemetry

Abstract

This study was performed in order to investigate fish behavior and to obtain biological characteristics using the acoustic telemetry. The experimental works were conducted in the marine ranching area in Tongyeong, South Korea. The target fish (mackerel, Scomber japonicus) was handled with a minimum of trauma, and the implantation of the tag in the abdominal cavity was done by surgery procedure. The study was divided into the neap and the spring tide, from 13 to 14 November 2010 and from 19 to 20 December 2010, respectively. Fish was altered by the light cycle, which is approved by our results of vertical movement where in the neap tide, the average swimming depth was 6.0 m (±0.5) during a daytime and 5.6 m (±0.9) at night and in the spring tide, the average swimming depth was 6.6 m (±0.8) during a daytime and 3.9 m (±1.5) at night. The swimming depth was affected by high current. In this result, sunlight was a main stimulus to affect on the vertical movement in the cage. For the horizontal movement, in the neap tide, the distribution of the positions had a circular shape and was focused in the middle of the net cage, however, The positions were, more scattered along the x-axis in the spring tide than in the neap tide and appeared an ellipsoidal shape. These results have the potential to improve our knowledge of fish behavioral capabilities of temperate species, and advance the capability of biophysical dispersal models to predict the probabilities of dispersal and retention in coastal zones.