Opportunistic visitors: long-term behavioural response of bull sharks to food provisioning in Fiji

Brunnschweiler, Juerg M., and Barnett, Adam (2013) Opportunistic visitors: long-term behavioural response of bull sharks to food provisioning in Fiji. PLoS ONE, 8 (3). e58522. pp. 1-15.

[img]
Preview
PDF (Published Version) - Published Version
Available under License Creative Commons Attribution.

Download (3MB) | Preview
View at Publisher Website: http://dx.doi.org/10.1371/journal.pone.0...
 
44
97


Abstract

Shark-based tourism that uses bait to reliably attract certain species to specific sites so that divers can view them is a growing industry globally, but remains a controversial issue. We evaluate multi-year (2004–2011) underwater visual (n = 48 individuals) and acoustic tracking data (n = 82 transmitters; array of up to 16 receivers) of bull sharks Carcharhinus leucas from a long-term shark feeding site at the Shark Reef Marine Reserve and reefs along the Beqa Channel on the southern coast of Viti Levu, Fiji. Individual C. leucas showed varying degrees of site fidelity. Determined from acoustic tagging, the majority of C. leucas had site fidelity indexes >0.5 for the marine reserve (including the feeding site) and neighbouring reefs. However, during the time of the day (09:00–12:00) when feeding takes place, sharks mainly had site fidelity indexes <0.5 for the feeding site, regardless of feeding or non-feeding days. Site fidelity indexes determined by direct diver observation of sharks at the feeding site were lower compared to such values determined by acoustic tagging. The overall pattern for C. leucas is that, if present in the area, they are attracted to the feeding site regardless of whether feeding or non-feeding days, but they remain for longer periods of time (consecutive hours) on feeding days. The overall diel patterns in movement are for C. leucas to use the area around the feeding site in the morning before spreading out over Shark Reef throughout the day and dispersing over the entire array at night. Both focal observation and acoustic monitoring show that C. leucas intermittently leave the area for a few consecutive days throughout the year, and for longer time periods (weeks to months) at the end of the calendar year before returning to the feeding site.

Item ID: 34292
Item Type: Article (Research - C1)
ISSN: 1932-6203
Funders: Save Our Seas Foundation, Shark Foundation Switzerland
Date Deposited: 08 Aug 2014 04:26
FoR Codes: 06 BIOLOGICAL SCIENCES > 0602 Ecology > 060201 Behavioural Ecology @ 100%
SEO Codes: 96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960808 Marine Flora, Fauna and Biodiversity @ 100%
Downloads: Total: 97
Last 12 Months: 15
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page