Marine reserves can protect fish populations by increasing abundance and body size, but less is known about the effect of protection on fish behaviour. We looked for individual consistency in movement behaviours of sea trout in the marine habitat using acoustic telemetry to investigate whether they represent personality traits and if so, do they affect survival in relation to protection offered by a marine reserve. Home range size had a repeatability of 0.21, suggesting that it represents a personality trait, while mean swimming depth, activity and diurnal vertical migration were not repeatable movement behaviours. The effect of home range size on survival differed depending on the proportion of time fish spent in the reserve, where individuals spending more time in the reserve experienced a decrease in survival with larger home ranges while individuals spending little time in the reserve experienced an increase in survival with larger home ranges. We suggest that the diversity of fish home range sizes could be preserved by establishing networks of marine reserves encompassing different habitat types, ensuring both a heterogeneity in environmental conditions and fishing pressure.

Movement data were collected in the Tvedestrand fjord (3.8 km², max depth: 87 m) located in southern Norway between spring 2013 and fall 2017. A telemetry array consisting of 50 Vemco VR2-W receivers (VEMCO Ltd., Halifax, Canada) was deployed in the fjord, with the receivers being attached to moorings and kept at three metres depth aided by sub-surface buoys. Sea trout were caught around the centre islands of the fjord in 2013 (April: n = 3; May: n = 26; September: n = 24; November: n = 7), 2015 (June: n = 3; October: n = 14; November: n = 5) and 2016 (April: n = 4; May: n = 7) using a beach seine, and also by electrofishing in the spawning river at November 11, 2016 (n = 23). We used Vemco V9P and V13P transmitters, which had a maximum battery life of 508-696 and 1292 days, respectively. Signals were emitted with a random delay of 180 ± 70 seconds. Accuracy and resolution of depth measurements were ± 2.5 m and 0.22 m, respectively, and max depth was 50 m or more for the different tags.

There are three types of data sets:

• Fish tagging data: Individual information on tag ID, tag type, tagging location, capture method, time of tagging, body length and weight.

• Tvedestrand receiver locations

• Detection data per individual fish (xxxx_VUE_Export_edited): Detection data exported from VUE. Time stamps are in local time for Norway. Data after assumed death has been removed and single detections within one day has been removed. Depth data from malfunctioning depth sensors has been removed.