Very nice - watch.
I say, Vinaka Vakalevu - much appreciated, and glad that you've enjoyed the experience!
PS - Shawn on the PADI blog right here!
Enjoy!
PS - Shawn on the PADI blog right here!
Enjoy!
Blog about "The World's best Shark Dive" by Beqa Adventure Divers. Featuring up to eight regular species of Sharks and over 400 different species of fish, Shark diving doesn't get any better!
Neither the SharkBanz bracelet nor leash affected the behaviour of white sharks or reduced the percentage of baits taken.These products rely on permanent magnets (Grade C8 barium ferrite), which have previously been used to overwhelm the electromagnetic sense of sharks .....However, the distance from which sharks reacted to magnets in those studies was small, typically less than 0.5 m and the effectiveness of the magnets decreased with increasing shark motivation.Barium-ferrite permanent magnets generate a flux that decreases at the inverse cube in relation to the distance from the magnet, from near 1000 G at the source to an amount comparable to the Earth’s magnetic field (0.25 – 0.65 G) at distances of 0.30 – 0.50 m, showing how rapidly the magnetic field decreases. Sharks would therefore need to be at less than 0.30 m for such magnets to act as real deterrents.This suggests that magnets are unlikely to be effective at deterring sharks because they will only protect close to the magnet, limiting their applicability as personal deterrents...
if a particular type of commercially available shark deterrent happens to be less effective (or completely ineffective) as advertised, it can give users a false sense of security, potentially encouraging some to put themselves at greater risk than is necessary. For example, some surfers and spearfishers probably ignore other mitigation measures, such as beach closures, because they ‘feel safe’ when wearing these products.
The suite of studies available for this site is likely the most comprehensive body of work to date comparing the impacts of tourism on a predator species' behaviour and fitness with conservation and economic benefits.
The various studies address a range of potential issues (e.g. residency, habitat use, consumption of bait, energetic value of bait and diet) and provide a good example of how site-specific information, obtained from multiple methods, can contribute for an effective, evidence- based, management of the predator tourism industry.
Similar multi-methods approaches can be applied to other aquatic and terrestrial wildlife tourism species/operations, to move beyond our current understanding of tourism-driven behavioural and ecological changes, and provide a more holistic understanding of the effects of provisioning on the health and fitness of the target species.
Results from the present study, particularly when combined with information from previous studies at this feeding site (Brunnschweiler et al., 2010, 2014;Brunnschweiler and Baensch, 2011; Brunnschweiler and Barnett, 2013;Brunnschweiler et al., 2017), suggest that current levels of provisioning lead to no detrimental long-term impacts on the behaviour or diet (and probably health) of sharks at the Shark Reef Marine Reserve site.
"Best practice" among cage diving operations apparently consists in just teasing, but never actually handing any bait to the Sharks.
Were I a Shark hugger, I would immediately object that letting the Sharks waste precious energy on fruitless "hunts" is to be rejected as it is likely harmful to the animals.
Although sharks are enticed to the cage-diving vessels with baits, industry regulations do not allow operators to feed white sharks and strict limits on the amount of bait and berley are now in place in South Australia and at other white shark cage-diving locations (Bruce, 2015).
Energy burden from the increased activity is, therefore, not rewarded by regular bait provisioning.
Some baits can, however, be consumed when sharks approach the baits using high speed or stealth (Huveneers et al., 2015).
The baits used in SA are composed of gills and stomach lining of southern bluefin tuna and are not as energy-rich as white shark’s natural prey while at these sites (e.g. pinnipeds). Whether the infrequent consumption of these baits provide sufficient energy to compensate for the increased energy expenditure associated with sharks interacting with the operators would depend on the calorific value of these baits and the frequency of white sharks successfully feeding on the baits, both of which are currently unknown (Brunnschweiler et al., 2017).
Spending time interacting with cage-diving operators might also distract sharks from normal behaviours such as foraging on natural, energy-rich prey like pinnipeds.
Combined, these suggest that the increased energy expenditure associated with cage-diving interactions might not be compensated for by either bait or natural prey consumption.
One could, therefore, argue that white sharks should be able to feed on some bait to compensate for the energetic losses resulting from interacting with cage-diving operators.
Bioenergetic models (e.g. Barnett et al., 2016) would, however, be necessary to accurately assess the likely effect of cage-diving on white shark energy balance and whether such compensation is necessary or beneficial. Beyond the potential for short-term energy intake, other aspects of food provisioning (e.g. quality of food, potential for changes in foraging behaviour) would also need to be considered.