Fig 1.
A) Map of the study area including coastal bathymetry (black lines). Black circle indicates Argyrosomus regius tagging location (tuna trap) and stars denote the pop up/recovery locations of the satellite archival tags with the number indicating the fish ID. Note: Tags from fish #1, #2 and #21 only reported their position weeks after pop-up and thus the positions were obtained after a period of surface drifting. B) The Tunipex tuna trap found off Fuzeta and used to capture adult A. regius individuals tagged in this study. C) A diver releasing a PSAT tagged adult A. regius.
Table 1.
Deployment summary, showing fish ID, total length (TL; in cm), tagging and pop-up dates, number of days attached, mean (± SD) and maximum depth (in m), mean (± SD), minimum and maximum temperature (in °C) and data source used in the analysis from the satellite tags deployed on adult Argyrosomus regius off the southern coast of Portugal.
* denotes the individuals recaptured. Bold indicate the recovered tags.
Fig 2.
Temperature and depth profiles for 11 Argyrosomus regius tagged with PSAT tags off the Southern Portuguese coast in 2018 (Fish #1,2,3,4,5,6,8) and 2019 (Fish # 17,18,20,21).
Note: grey dots are due to the lack of water temperature data. Tags from fish #3, #4, #5, #8, #18 and #20 were physically recovered and therefore full datasets were obtained instead of transmitted summaries.
Table 2.
Individual fish tagging summary information as well as summarised percentage of time spent within a specific depth and temperature bin.
Data has been conditionally formatted within each column on a scale from green (lowest use) to red (highest use). Data days with fewer than 66% of transmissions have been filtered out, resulting in the exclusion of fish #21. *Denote full archival datasets.
Fig 3.
Daily maximum depth dives and their corresponding temperature for each Julian day covered during this study for tagged Argyrosomus regius.
The fitted blue line represents a Loess smoother fitted to data and the shaded area the standard error around the fitted estimate.
Table 3.
P-value results of the Games Howell post-hoc test comparing the number of daily maximum depth dives between months of the year for tagged Argyrosomus regius.
Values in parentheses denote the number of daily maximum depth dives used in the analysis, bolded values indicate statistical significance <0.01. Coloured heading correspond to months within each Austral season: spring (green), summer (yellow), autumn (orange), winter (blue).
Fig 4.
Contour plots of the average hourly depth and temperatures recorded by six PSAT-tagged Argyrosomus regius from which archival data was retrieved for each month of the year.
Dashed lines indicate crepuscular hours around the study site.