Home range and diel behavior of the ballan wrasse, Labrus bergylta, determined by acoustic telemetry

Abstract

Effective fisheries management needs to consider spatial behavior in addition to more traditional aspects of population dynamics. Acoustic telemetry has been extensively used to provide information on fish movements over different temporal and spatial scales. Here, we used a fixed-receiver array to examine the movement patterns of Labrus bergylta Ascanius 1767, a species highly targeted by the artisanal fleet of Galicia, NW Spain. Data from 25 individuals was assessed for a period of 71days between September and November 2011 in the Galician Atlantic Islands Maritime-Terrestrial National Park. Fish were present within the monitored area more than 92% of the monitored time. The estimated size of individual home ranges, i.e. the area where fish spent most of their time, was small. The total minimum convex polygons area based on all the estimated positions was 0.133±0.072km2, whereas the home range size estimated using a 95% kernel distribution of the estimated positions was 0.091±0.031km2. The core area (50% kernel) was 0.019±0.006km2. L. bergylta exhibited different patterns of movement in the day versus the night, with 92% of the fish detected more frequently and traveling longer distances during the daytime. In addition, 76% of the fish displayed a larger home range during the day versus during the night. The linearity index was less than 0.005 for all fish suggesting random movements but within a relatively small area, and the volume of intersection index between consecutive daily home ranges was 0.75±0.13, suggesting high site fidelity. The small home range and the sedentary behavior of L. bergylta highlight the potential use of small MPAs as a management tool to ensure a sustainable fishery for this important species.