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  • 1
    In: Marine and Freshwater Research, CSIRO Publishing, Vol. 69, No. 1 ( 2018), p. 144-
    Abstract: Southern stingrays (Hypanus americanus) represent a multimillion dollar ecotourism operation in Grand Cayman, interacting with over a million visitors annually. Over 30 years of stingray provisioning by tour operators has provided a predictable aggregation at the Stingray City Sandbar (SCS). Despite potentially negative effects of provisioning and concerns about declining stingray numbers at SCS, there has never been a formal assessment of the aggregation. In the present study we analysed tagging data from 2002 to 2015 and established structured censuses monitoring the aggregation. The consistently female-dominated aggregation declined between 2008 and 2012, from 〉 100 to 〈 60 stingrays, but has increased since 2012, stabilising at ~90 stingrays. Female site fidelity was high, with ~20% of females resident for ≥10 years, compared with only 3 years for most males. Stingrays were also found to have growth rates similar to those in captivity. The results of the present study suggest the SCS aggregation is highly dependent on individuals arriving from the island-wide stingray population, susceptible to perturbation, and that successful management of activities at SCS will benefit from regular monitoring of the stingray aggregation. We chronicle the historical status of this well-known and economically valuable marine resource and provide suggestions applicable towards sustainable human–marine wildlife interactions for similar resources.
    Type of Medium: Online Resource
    ISSN: 1323-1650
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 2018
    detail.hit.zdb_id: 1283028-8
    SSG: 12
    SSG: 21,3
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  • 2
    Online Resource
    Online Resource
    CSIRO Publishing ; 2021
    In:  Marine and Freshwater Research Vol. 73, No. 1 ( 2021-11-4), p. 125-132
    In: Marine and Freshwater Research, CSIRO Publishing, Vol. 73, No. 1 ( 2021-11-4), p. 125-132
    Abstract: The roosterfish (Nematistius pectoralis) is a piscivorous predator targeted extensively in recreational fisheries throughout the eastern tropical Pacific; however, its biology is poorly understood. To address these shortcomings, we investigated vertical habitat use and behaviour of roosterfish in coastal Panama using pop-up satellite archival tags. Nearly 5000 h of vertical movement data across 274 days from five fish showed that roosterfish largely used the upper 10 m and 20 m of the water column during the night-time and daytime respectively, and rarely left the mixed layer. Roosterfish diving behaviour showed a clear diurnal pattern, with oscillatory dives beginning during dawn and continuing through dusk. Accelerometer data showed that this period was also associated with a sharp increase in activity during dawn and a decrease around sunset. Whereas previous work in shallow systems ( 〈 20 m) with limited structure showed that roosterfish were vertically active sporadically throughout the day and mostly during crepuscular periods, our study showed that in a habitat with continuous structure, roosterfish were continuously vertically active from dawn till dusk, possibly because foraging behaviours were limited by light levels rather than prey-congregating structure. Such changes in dive patterns illustrate how habitat influences behaviour and the importance of studying organisms throughout their range.
    Type of Medium: Online Resource
    ISSN: 1323-1650 , 1448-6059
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 2021
    detail.hit.zdb_id: 1283028-8
    SSG: 12
    SSG: 21,3
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  • 3
    In: Marine and Freshwater Research, CSIRO Publishing, Vol. 69, No. 10 ( 2018), p. 1487-
    Abstract: Whale sharks (Rhincodon typus) are an endangered species whose growth and reproductive biology are poorly understood. Given their conservation concern, estimating growth parameters, as traditionally derived from vertebral samples of dead animals, is challenging. We used a non-invasive approach to investigate growth parameters of whale sharks frequenting the South Ari Atoll, Maldives, by analysing repeat measurements of free-swimming sharks over a 10-year period. Total lengths of the sharks were estimated by three measurement methods. Visual estimates underestimated the sizes of large sharks, whereas laser and tape measurements yielded results that were similar to one another. The Maldives aggregation consisted of primarily male (91%) juvenile (total length=3.16–8.00m) sharks and sharks new to the area were significantly smaller than were returning sharks, which suggests that this site may constitute a secondary nursery ground. Estimates of von Bertalanffy (VBG) growth parameters for combined sexes (L∞=19.6m, k=0.021year–1) were calculated from 186 encounters with 44 sharks. For males, VBG parameters (L∞=18.1m, k=0.023year–1) were calculated from 177 encounters with 40 sharks and correspond to a male age at maturity of ~25 years and longevity of ~130 years. Differences between these estimates and those from other studies underscore the need for regional studies.
    Type of Medium: Online Resource
    ISSN: 1323-1650
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 2018
    detail.hit.zdb_id: 1283028-8
    SSG: 12
    SSG: 21,3
    Location Call Number Limitation Availability
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  • 4
    Online Resource
    Online Resource
    CSIRO Publishing ; 2012
    In:  Marine and Freshwater Research Vol. 63, No. 11 ( 2012), p. 1077-
    In: Marine and Freshwater Research, CSIRO Publishing, Vol. 63, No. 11 ( 2012), p. 1077-
    Abstract: Knowledge of movements and habitat use is necessary to assess a species’ ecological role and is especially important for mesopredators because they provide the link between upper and lower trophic levels. Using acoustic telemetry, we examined coarse-scale diel and seasonal movements of elasmobranch mesopredators on a shallow sandflat in Shark Bay, Western Australia. Giant shovelnose rays (Glaucostegus typus) and reticulate whiprays (Himantura uarnak) were most often detected in nearshore microhabitats and were regularly detected throughout the day and year, although reticulate whiprays tended to frequent the monitored array over longer periods. Pink whiprays (H. fai) and cowtail stingrays (Pastinachus atrus) were also detected throughout the day, but were far less frequently detected. Overall, there was no apparent spatial or temporal partitioning of the sandflats, but residency to the area varied between species. In addition, ray presence throughout the year suggests that previously observed differences in seasonal abundance are likely because of seasonal changes in habitat use rather than large-scale migrations. Continuous use of the sandflats and limited movements within this ray community suggests that rays have the potential to be a structuring force on this system and that focusing on nearshore habitats is important for managing subtropical ray populations.
    Type of Medium: Online Resource
    ISSN: 1323-1650
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 2012
    detail.hit.zdb_id: 1283028-8
    SSG: 12
    SSG: 21,3
    Location Call Number Limitation Availability
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