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- Diel activity and variability in habitat use of white sea bream in a temperate marine protected area
- Fish populations are often comprised of individuals that use habitats and associated resources in different ways. We placed sonic transmitters in, and tracked movements of, white sea bream (Diplodus sargus sargus) in the no-take zone of a Mediterranean marine protected area: the Torre Guaceto marine protected area, (Adriatic Sea, Italy). Tagged fish displayed three types of diel activity patterns in three different habitats: sand, rocky reefs and “matte” of the seagrass Posidonia oceanica. Individuals were more active during the day than at night. Overall, white sea bream displayed a remarkable behavioural plasticity in habitat use. Our results indicate that the observed behavioural plasticity in the marine protected area could be the result of multiple ecological and environmental drivers such as size, sex and increased intra-specific competition. Our findings support the view that habitat diversity helps support high densities of fishes., Available online
- Di Lorenzo, Fernandez, Badalamenti, Guidetti, Starr, Giacalone, Di Franco, D'Anna
- Fitting the size of no-take zones to species movement patterns: A case study on a Mediterranean seabream
- No-take zones (NTZs) have been shown to be useful tools for marine conservation and fishery management, although the lack of information on species' movements often makes it difficult to properly establish NTZ size. Using acoustic telemetry techniques, we monitored the movements, home range (HR) and homing ability (to capture sites) of 22 adult white seabream Diplodus sargus sargus in a fully protected portion (138.60 ha) of the Torre Guaceto Marine Protected Area (SE Italy). After release at a different location than the site of capture, 85% of the tagged fish returned to the capture site within 3 d. Fish were monitored for 161 d. All tagged fish spent most of the time within the monitoring area (fish presence index = 92.8%) and showed a mean HR of 20.6 ha. These results indicate that the studied NTZ effectively protects seabream, as it entirely encompasses their HRs, which are on average far smaller than the reserve. Twelve individuals left the monitoring area during the period of the year that corresponds to their known time of spawning. This potential emigration during the spawning period indicates that the reserve alone does not fully protect white seabream and that other management options, such as a seasonal fishing closure during the reproductive period, may be needed. Estimates of movement patterns and HRs of fishes, therefore, represent useful information to better understand, refine and enhance the value of NTZs for protecting ecologically valuable species. © Inter-Research 2014.
- Di Lorenzo, D'Anna, Badalamenti, Giacalone, Starr, Guidetti