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As ecotourists become increasingly interested in snorkeling and diving with sharks, it is important to establish directives for safe interactions. The study considered eye contact between humans an...

Background:Close-up videos of sharks foraging on other live sharks are rare, especially when it comes to footage of the entire duration of an event.Objective:Our goal was to present an in-depth analysis involving a Galapagos shark,Carcharhinus galapagensis, foraging on a whitetip reef shark,Triaenodon obesus.Method:A frame by frame video examination was used to highlight the different aspects of this bout.Results:Several behavioral characteristics, including the somewhat cryptic approach, the extensive shaking once the Galapagos shark had the whitetip reef shark between its jaws, and devouring tail-first, stand out in this event.Conclusion:The entire act appeared very smooth, indicating that this bout, or at least parts thereof, may represent a common hunting strategy for Galapagos sharks.

The trends of the world’s top ten countries relating to shark bite rates, defined as the ratio of the annual number of shark bites of a country and its resident human population, were analyzed for the period 2000-2016. A nonparametric permutation-based methodology was used to determine whether the slope of the regression line of a country remained constant over time or whether so-called joinpoints, a core feature of the statistical software Joinpoint, occurred, at which the slope changes and a better fit could be obtained by applying a straight-line model. More than 90% of all shark bite incidents occurred along the US, Australia, South Africa, and New Zealand coasts. Since three of these coasts showed a negative trend when transformed into bite rates, the overall global trend is decreasing. Potential reasons for this decrease in shark bite rates—besides an increase in the world’s human population, resulting in more beach going people, and a decrease of sharks due to overfishing—are discussed.

Amin, R.; Ritter, E., and Wetzel, A., 2015. An estimation of shark-attack risk for the North and South Carolina coastline. A spatiotemporal cluster analysis of shark-attack rates is applied to identify coastal areas with shark-attack rates that are very high or very low along the North and South Carolina coast. Using a cluster analysis makes it possible to not just pinpoint these areas with more accuracy but also identify where incidents are unlikely to happen. In the past, shark attacks have been studied from a viewpoint of encounter number per region and so limited to the areas in which the attacks occurred. A first look is also taken of the potential influences of some anthropogenic, environmental, and meteorological factors for North and South Carolina in comparison with the better-known attack-prone areas along Florida's coast, to quantify potential causes leading to elevated shark-attack rates, or the lack of them.

Mouth gaping in sharks has been considered to be either a threat display or a response to sharksucker irritation, but has never been examined in greater detail. Another form of gaping was observed frequently around feeding scenarios, primarily when sharks swam away from the food source. This form of a yawn-like behavior of Caribbean reef sharks, Carcharhinus perezi, was videotaped during both standard feeding and non-feeding scenarios, and examined for both proximate causation and function. This type of gaping reflects a simulated bite process, including all bite phases, but differs from actual bites in that the duration is as great as 10 times longer, with the expansion phase disproportionally prolonged and a pause at the gape's peak. Of all the possible functions discussed, a maintenance behavior to reposition the jaw elements after feeding fits all of the measured parameters.

The subject of this investigation was spatial and spatio-temporal shark attack clusters occurring along California‘s coast between 1994 and 2010. Two hypotheses were postulated: (a) Shark attacks are proportionate to human beach activities. (b) No pronounced space-time relationship between human beach activity and shark attacks exists along this coast over time. The hypotheses were tested by using SaTScan TM version 9.1.1, a spatial scan statistic program. The results show that well-defined high- and low-risk areas have prevailed along the coast over the years. Because most attacks in California waters are attributed to white sharks, this animal was used as a model species to discuss the results.