Importance of fisheries discards and experience for seabird behavior and energetics
Oceanography
Final Report Abstract
Marine habitats are deeply altered by human activities which can represent important conservation issues for marine animals. In this study we investigated about the influence of commercial fishing and recreational tourism on the foraging behaviour of a central place marine predator, the Scopoli’s shearwater (Calonectris diomedea). The data were collected at Linosa Island, located in the Sicily Channel (35°51’33” N; 12°51’34” E) during the breeding seasons of 2014, 2015 and 2016. We tracked a total of 135 breeding birds which were equipped with GPS, accelerometer and Time Depth Recorder (TDR) loggers. The foraging behaviour of seabirds was determined through the identification of behaviours and dive events using accelerometer data. Scopoli’s shearwaters is a shallow-diving seabirds and the pressure sensor alone was not sufficient to identify all dives performed by birds. Fishing activities influenced the foraging behaviour of Scopoli’s shearwaters. Seabirds increased the time spent sitting on the water within 1.28 ± 0.13 km of fishing vessels likely feeding on or waiting for discards. However, despite the high density of fishing vessels operating in the home range of Scopoli’s shearwaters, only 40% of birds interacted with a fishing vessel during their foraging trips. These birds showed a lower foraging efficiency than birds did not interact with fishing vessels. This results suggest that fisheries discard consumption might not be a profitable source of food for Scopoli’s shearwaters. The studies included in this project contribute to increase our knowledge of the behavioural ecology of the threatened Scopoli's shearwater in the south-central Mediterranean Sea. In particular, we showed how some human activities can affect the behaviour of seabirds. Moreover, the methods used in these studies can be applied to threatened seabird species worldwide, and thus help to plan appropriate conservation.
Publications
- (2017). A new algorithm for the identification of dives reveals the foraging ecology of a shallow-diving seabird using accelerometer data. Marine Biology, 164, 77
Cianchetti-Benedetti, M., Catoni, C., Kato, A., Massa, B., & Quillfeldt, P.
(See online at https://doi.org/10.1007/s00227-017-3106-0) - (2018). Interactions between commercial fishing vessels and a pelagic seabird in the southern Mediterranean Sea. BMC Ecology, 18, 54
Cianchetti-Benedetti, M., Dell’Omo, G., Russo, T., Catoni, C., & Quillfeldt, P.
(See online at https://doi.org/10.1186/s12898-018-0212-x)
