Correction: Long-Term Changes in Species Composition and Relative Abundances of Sharks at a Provisioning Site
نویسندگان
چکیده
Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier) displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas) of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004-2006 and 2007-2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004-2006 and very rare in the period of 2007-2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive exclusion among shark species.
منابع مشابه
Five decades of decline in sharks of Iran
Shark stocks in Iranian water of the Persian Gulf and Gulf of Oman are declining sharply. Although fishing and heavy fines have been banned by the organizations in charge of fishing for these fish, bycatch in some fishing methods, including Neritic and oceanic Gillnet, trawl fish and shrimp, long loine and trolling, still catch sharks. Slowly In this study, during a period of 10 years from 2010...
متن کاملLearning from a provisioning site: code of conduct compliance and behaviour of whale sharks in Oslob, Cebu, Philippines
While shark-based tourism is a rapidly growing global industry, there is ongoing controversy about the effects of provisioning on the target species. This study investigated the effect of feeding on whale sharks (Rhincodon typus) at a provisioning site in Oslob, Cebu, in terms of arrival time, avoidance and feeding behaviour using photo-identification and focal follows. Additionally, compliance...
متن کاملEffects of range condition on the temporal diet selection by goats in steppe rangelands of Iran
One of the key factors in managing a rangeland is to determine the relative preference of its major plant species by thegrazing livestock. Preference value of each plant species is affected by plant type, companion plants, availability byanimals, phenological stage, climate condition, and the livestock species. We investigated the grazing behaviour of anative goat (Garizi) in the steppe rangela...
متن کاملSeasonal and Long-Term Changes in Relative Abundance of Bull Sharks from a Tourist Shark Feeding Site in Fiji
Shark tourism has become increasingly popular, but remains controversial because of major concerns originating from the need of tour operators to use bait or chum to reliably attract sharks. We used direct underwater sampling to document changes in bull shark Carcharhinus leucas relative abundance at the Shark Reef Marine Reserve, a shark feeding site in Fiji, and the reproductive cycle of the ...
متن کاملInjectable Cartilage Shaving: An Autologous and Long Lasting Filler Material for Correction of Minor Contour Deformities in Rhinoplasty
BACKGROUND Filler materials are gaining popularity in nonsurgical rhinoplasty the major advantages are the ability to camouflage the surface deformities, and also the soft and malleable consistency while the major drawback of the safe fillers such as hyaluronic acid is short durability. In this study, we evaluated the injectable cartilage shaving as an autologous filler material for correction...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 9 شماره
صفحات -
تاریخ انتشار 2014