In a correspondence focusing on our hypothesis of “problem individuals” being responsible for most human fatalities within large‐bodied shark populations (Clua & Linnell, ), Neff ( ) raises some ...concerns about how our hypothesis may be perceived by the public and managers. ...while our “problem individual” and a “rogue” shark could indeed both tend to repeat an initial strike on a human being, as a potential prey, in our perspective, the latter would develop a malicious and targeted preference for human prey as embodied by films such as “Jaws.” By focusing on the numerous mechanisms that can lie behind nonfatal bites on humans, or raising an anthropomorphic interpretation of an animal behavior in response to our hypothesis, Neff unfortunately overlooks most of our attempt to come up with alternative explanatory mechanisms behind fatal shark attacks and develop testable hypotheses and appropriate alternative management actions.
Shark and ray provisioning Brena, Pierpaolo F.; Mourier, Johann; Planes, Serge ...
Marine ecology. Progress series (Halstenbek),
10/2015, Letnik:
538
Journal Article
Recenzirano
The use of olfactory stimuli and the provision of food are a common practice to prompt artificial aggregations of emblematic wild species and ensure the economic viability of the wildlife-watching ...industry. Several elasmobranch species have been targeted by such operations in a variety of locations for over 4 decades. A recent review succinctly addressed the potential effects of shark diving tourism, including shark provisioning, on shark individual behavior and ecology, but the paucity of data on the ecology of elasmobranchs precluded general statements. By using a functional framework, we reviewed the findings of the 22 available studies that investigated the behavioral, physiological, and ecological response of 14 shark and 3 ray species targeted by artificial provisioning. Focusing on the underlying processes that rule the response of targeted elasmobranch species, we report further effects acting beyond the individual scale. We suggest that the most commonly described alterations of individual movement patterns have cascading effects through the group and community scales, ultimately resulting in altered health condition and individual behavior toward humans. We conclude by stressing the potential for provisioning activities to support the investigation of complex ecological and behavioral processes in elasmobranchs.
Contraceptive treatment before gonadotrophin-releasing hormone agonist administration presents advantages in women with a tendency to hyper-response and simplifies donor–recipient treatment ...synchronization. This study compares response to gonadotrophin stimulation under hypophyseal suppression in oocyte donors with or without vaginal contraceptive pretreatment. METHODS: One hundred and ninety oocyte donors were recruited in a single centre and prospectively assigned to one of two treatment groups, according to the day of the week menstruation initiated: Group VC–, no prior vaginal contraceptive and Group VC+, prior vaginal contraceptive. RESULTS: VC+ patients presented a significantly higher cancellation rate, lower plasma estradiol levels and fewer follicles >12 mm on the day of hCG, versus the VC– group. Number of oocytes recovered was significantly lower in the VC+ group. All the cases of severe ovarian hyperstimulation syndrome (SOHSS) were in the VC– group. Pregnancy rates by embryo transfer to synchronic recipients were similar between VC+ and VC– (59.5 versus 57.9%, respectively). CONCLUSIONS: Vaginal contraceptive pretreatment resulted in a higher ovarian suppression, whereas SOHSS rate was lower than in donors who did not receive pretreatment. There were no differences in pregnancy rates between the two groups of synchronic oocyte recipients.
The feeding of marine predators is a popular means by which tourists and tour operators can facilitate close observation and interaction with wildlife. Shark-feeding has become the most developed ...provisioning activity around the world, despite its controversial nature. Amongst other detrimental effects, the long-term aggregation of sharks can modify the natural behaviour of the animals, potentially increase their aggression toward humans, and favour inbreeding. During 949 diving surveys conducted over 44 mo, we investigated the ecology and residence patterns of 36 photo-identified adult sicklefin lemon sharks Negaprion acutidens. The group contained 20 females and 16 males. From this long-term survey, we identified 5 different behavioural groups that we described as 'new sharks' (7), 'missing sharks' (4), 'resident sharks' (13), 'unpredictable sharks' (5) and 'ghost sharks' (7). In spite of movements in and out of the area by some males and females, which were probably related to mating, the general trend was that residency significantly increased during the study, particularly in males, showing a risk of inbreeding due to the reduction of shark mobility. Intra- and interspecific aggression was also witnessed, leading to an increased risk of potentially severe bites to humans. Our findings suggest the need for a revision of the legal framework of the provisioning activity in French Polynesia, which could include a yearly closure period to decrease shark behavioural modifications due to long-term shark-feeding activities.
Data‐limited fisheries assessment methods have great potential to help inform small island communities on the status of their fisheries resources. In this paper, we provide a length‐based assessment ...of an artisanal fishery that primarily targets spawning aggregations of Shortjaw Bonefish Albula glossodonta at Anaa Atoll in the Tuamotu Archipelago of French Polynesia. We assessed the length‐frequency distribution of the spawning stock across a 3‐year period (2016–2018). During this time, male and female Shortjaw Bonefish were fully recruited to the fishery at age 4 and age 5, respectively. Fishing mortality was over two times the range of natural mortality for this species (i.e., 0.21–0.32), and based on these estimates of natural mortality, the annual spawning potential ratio of the population was between 7% and 20% across the sampling years. The majority of the catch was sexually mature, with 78, 95, and 95% of the annual female catch in 2016, 2017, and 2018, respectively, being equal to or greater than the length of first maturity (i.e., 48 cm FL). However, every fisheries indicator and biological reference point suggested that the fishery was overexploited and in need of management intervention. To this aim, the community of Anaa (1) established an Educational Managed Marine Area, which overlaps with the Shortjaw Bonefish migratory corridor adjacent to Tukuhora village and (2) instated a temporal rahui (a traditional conservation method) inside the Educational Managed Marine Area during the peak months of the spawning season.
Shark-based ecotourism has been recently expanding around the world. Provisioning sharks, however, is not without risk and accidental bites on humans are regularly reported. Such events may ...jeopardise the shark ecotourism industry and local economies. Through a case study from French Polynesia, I investigated whether changes in feeding practices of lemon sharks between the early 1990s and 2013 are related to recent accidental bites of divers. Hand-feeding, ‘smelling’ and surface feeding facilitated the development of agonistic behaviour in sharks, which resulted in accidental bites. The level of interaction between sharks and humans appears to be the most important driver for analysing bite-risk. This paper presents the very first framework for risk-analysis and will allow managers to better manage the risk associated with current practices in shark-feeding around the world. The paper also provides technical guidelines for the design of adequate legal frameworks that will support any sustainable shark feeding operation.
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•Accidental bites linked to shark feeding can jeopardise this ecotourism industry.•Bite risk seems positively correlated with specific feeding practices.•The level of interactions between sharks and humans is a major driving factor.•Based on this hypothesis, I propose a framework for accidental bite risk analysis.•This tool should improve the management of shark-based ecotourism worldwide.
Abstract
Study question
Is there any difference in embryo euploidy rates following luteal phase phase (LS) and follicular phase (FS) start ovarian stimulation.
Summary answer
The number of euploid ...blastocysts and embryo euploidy rate are comparable when comparing FS and LS.
What is known already
Random start ovarian stimulation (starting at any time of the cycle) has been traditionally used in women undergoing urgent fertility preservation for medical reason. Although there is accumulating evidence that in infertile women, LS can result in equivalent number of oocytes and embryos as compared with FS, no study has evaluated the effect of luteal phase start ovarian stimulation on embryo euploidy rates. The current study is the first prospective study designed to evaluate embryo euploidy rates in donors undergoing two identical consecutive ovarian stimulation protocols within a period of 6 months starting either in the (FS), or (LS).
Study design, size, duration
In a prospective study, conducted between May 2018 and January 2020, 40 oocyte donors underwent two consecutive ovarian stimulation protocols within a period of 6 months with an identical fixed GnRH antagonist protocol starting either in the early follicular (FS), or and luteal menstrual cycle phase (LS).
Participants/materials, setting, methods
All participants underwent two identical consecutive ovarian stimulation cycles with 150μg corifollitropin alfa followed by 200 IU rFSH in a fixed GnRH antagonist protocol either in the FS or LS. Six MII oocytes from the same oocyte donor, from each stimulation cycle, were allocated to the recipients and were inseminated with the same sperm sample (recipients partner sperm or donor sperm). Embryos were cultivated to blastocyst stage followed by preimplantation genetic testing for aneuploidies (PGT-A).
Main results and the role of chance
When comparing FP with LP, the duration of ovarian stimulation was significantly shorter (9.68± 2.09 vs 10.93± 1.55 days), 95% CI -1.95; -0.55 and a higher total additional dose of daily recFSH was significantly lower (526.14± 338.94 IU vs 726.14± 366.27), 95% CI -315,12; -84,88 when CPT was administered in the luteal phase. . There were no differences in the hormone values on the triggering day (Estradiol 2137.61±1198.25 pg/ml vs 2362.96±1472.89); 95% CI -1160.45;709.76. Overall no differences were observed in the number of oocytes (24.84± 11.200 vs 24.27± 9.08); 95% CI-2,61; 3.75 and MII oocytes (21.41±10.19 vs 21.59± 8.81), 95%CI -2.72; 2.35 retrieved between FP and LP cycles in the oocytes donors. Following oocyte allocation and fertilization to the recipients, a total of 245 blastocysts were biopsied (blastocyst formation rate 245/408, 60.05%), 117 in FP group and 128 in LP group. The overall blastocyst euploidy rate was 59.18% . There were no differences in the number of euploid embryos between FS (1.59±1.32) and LS (1.70±1.29), mean difference 0.11, 95%CI -0.65; 0.46. Finally, there were no differences in the percentage of euploid embryos per oocytes inseminated between FS 70/287 (24.4%) and LP 75/278 (24.7%), mean difference -0.027, 95%CI -0.11; 0.06.
Limitations, reasons for caution
The study was performed in oocyte derived from potentially fertile young oocyte donors thus caution is needed when extrapolating the results in oocytes derived from infertile women of older age.
Wider implications of the findings
Luteal phase stimulation does not alter embryo euploidy status as compared with follicular phase stimulation and thus it appears that it can be safely used not only in cases of urgent medical fertility preservation but also in patients undergoing ovarian stimulation for IVF/ICSI.
Trial registration number
Clinical Trials Gov (NCT03555942).
Abstract
Study question
Is there any difference in embryo euploidy rates following luteal phase phase (LS) and follicular phase (FS) start ovarian stimulation. Summary answer: The number of euploid ...blastocysts and embryo euploidy rate are comparable when comparing FS and LS.
What is known already
Random start ovarian stimulation (starting at any time of the cycle) has been traditionally used in women undergoing urgent fertility preservation for medical reason. Although there is accumulating evidence that in infertile women, LS can result in equivalent number of oocytes and embryos as compared with FS, no study has evaluated the effect of luteal phase start ovarian stimulation on embryo euploidy rates. The current study is the first prospective study designed to evaluate embryo euploidy rates in donors undergoing two identical consecutive ovarian stimulation protocols within a period of 6 months starting either in the (FS), or (LS).
Study design, size, duration
In a prospective study, conducted between May 2018 and January 2020, 40 oocyte donors underwent two consecutive ovarian stimulation protocols within a period of 6 months with an identical fixed GnRH antagonist protocol starting either in the early follicular (FS), or and luteal menstrual cycle phase (LS).
Participants/materials, setting, methods
All participants underwent two identical consecutive ovarian stimulation cycles with 150μg corifollitropin alfa followed by 200 IU rFSH in a fixed GnRH antagonist protocol either in the FS or LS. Six MII oocytes from the same oocyte donor, from each stimulation cycle, were allocated to the recipients and were inseminated with the same sperm sample (recipients partner sperm or donor sperm). Embryos were cultivated to blastocyst stage followed by preimplantation genetic testing for aneuploidies (PGT-A).
Main results and the role of chance
When comparing FP with LP, the duration of ovarian stimulation was significantly shorter (9.68± 2.09 vs 10.93± 1.55 days), 95% CI –1.95; –0.55 and a higher total additional dose of daily recFSH was significantly lower (526.14± 338.94 IU vs 726.14± 366.27), 95% CI –315,12; –84,88 when CPT was administered in the luteal phase. . There were no differences in the hormone values on the triggering day (Estradiol 2137.61±1198.25 pg/ml vs 2362.96±1472.89); 95% CI –1160.45;709.76. Overall no differences were observed in the number of oocytes (24.84± 11.200 vs 24.27± 9.08); 95% CI–2,61; 3.75 and MII oocytes (21.41±10.19 vs 21.59± 8.81), 95%CI –2.72; 2.35 retrieved between FP and LP cycles in the oocytes donors. Following oocyte allocation and fertilization to the recipients, a total of 245 blastocysts were biopsied (blastocyst formation rate 245/408, 60.05%), 117 in FP group and 128 in LP group. The overall blastocyst euploidy rate was 59.18% . There were no differences in the number of euploid embryos between FS (1.59±1.32) and LS (1.70±1.29), mean difference 0.11, 95%CI –0.65; 0.46. Finally, there were no differences in the percentage of euploid embryos per oocytes inseminated between FS 70/287 (24.4%) and LP 75/278 (24.7%), mean difference –0.027, 95%CI –0.11; 0.06.
Limitations, reasons for caution
The study was performed in oocyte derived from potentially fertile young oocyte donors thus caution is needed when extrapolating the results in oocytes derived from infertile women of older age.
Wider implications of the findings: Luteal phase stimulation does not alter embryo euploidy status as compared with follicular phase stimulation and thus it appears that it can be safely used not only in cases of urgent medical fertility preservation but also in patients undergoing ovarian stimulation for IVF/ICSI.
Trial registration number
Clinical Trials Gov (NCT03555942).
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