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!
Pretty grim - and these bites are merely superficial! Click for detail.
Bingo!
From the Abstract.
Introduction: Shark-based ecotourism is significantly developing around the world, often without appropriate management of risk. This activity involves a risk of accidental bites on divers that can be quite severe or even fatal.
Objectives: To determine if ecotourism companies’ liability can be engaged in the context of bites on scuba divers in presence of hand-feeding practices, supporting the legitimacy of financial compensation for the victims.
Methods: We analyzed the development from the mid-eighties to 2010 of shark-based ecotourism through artificial provisioning practices in Moorea Island (French Polynesia) and more specifically the features and motivation of two bites on divers by Sicklefin Lemon sharks.
Results: The specific practice of hand-feeding can be considered as a facilitating factor for accidental bites on divers, potentially involving the diving operator’s responsibility.
Conclusions: Our findings should support the technical work of experts that might be called in such cases.
Didn't I tell you that the last paper had an agenda!
This one, titled Determining the Role of Hand Feeding Practices in Accidental Shark Bites on Scuba Divers is by one of the previous authors, my pal Eric Clua, and by, I believe, anthropologist Frédéric Torrente. It describes the history of the chaotic and now largely defunct Shark diving industry in Moorea along with two of the numerous non-predatory strikes by provisioned Sicklefin Lemons, see pic at top. It comes to the general conclusion that in certain cases, Shark diving operators may bear some responsibility and may even be liable should a client be injured.
Totally agree!
Like I've stated for many, many years, baited commercial Shark diving is not SCUBA diving, and the clients have a reasonable expectation that we operators keep them safe. Yes, we make them sign liability waivers which should hopefully exclude the most frivolous complaints - but when operators are clearly negligent, it is only fair that they be held accountable!
But having said that, Elke obviously likes to get real close and undoubtedly bears her share for the fiasco. Having been at the receiving end many a time, I can attest to the pressure those eager image hunters will bring to bear - not easy to handle in an industry where client satisfaction and word-of-mouth recommendations are critical to one's financial survival!
Long story short?
Good one Eric - and for you out there who STILL don't understand what it means to conduct Shark tourism dives, re-read a) these 90-odd posts about our industry and then, b) these 80-odd posts about the need for proper procedures!
Here in Fiji we may be possibly witnessing something similar - at least, that is our working hypothesis although we're still debating about how to test it. Maybe you remember this paper, and this picture.
It is an old graph of Bull Shark sightings.
In essence, it shows how the Bulls disappear at year end for pupping and mating, and how they then return for the Running of the Bulls in late December/January.
But there's also another detail - see it?
Every March/April, an this usually around the Full Moon, we get a notable temporary dip in the number of Bull Sharks. Our hypothesis is that they are being drawn away by some event that is likely linked to predation - and it just so happens that many Fishes like incidentally those Surgeonfish form spawning aggregations around the Full Moon, this because the associated strong tides favor maximum dispersion of the fertilized eggs.
Obviously, so far, this is only a correlation and thus merely speculative - but it is a testable hypothesis and if certain things come to pass like we plan them to, we may soon be nearer to solving that riddle!
(A) Map of the study location. (B) The genetic network
of adult lemon sharks. Each individual is indicated by a node labelled
by shark ID. Circles and squares indicate females and males respectively
and symbol size is indicative of the body length of the shark. Node
colour corresponds to the three defined residency groups. Dyads sharing a
first-order genetic relationship are connected by a line, with line
thickness indicating the strength of the genetic relationship
(proportional to R values). (C) Genetic degree (number of first-order
genetic relationships an individual has) distribution within the
population - click for detail!
I was somewhat underwhelmed, and said so - which led to a personal visit by the very charming Eric Clua, and to a real interesting ongoing dialogue with Johann Mourier. And despite of a toothy (!) public debate between Juerg and Jon and the authors, everybody remains on best terms and is eager to share and discuss. That's how science advances and as Eric stated, everybody agrees that nous jouons dans la même équipe and that everybody profits by sharing ideas and engaging in spirited discussions.
The feeding paper did raise the concern that the observed increased residency of some Lemons might lead to increased inbreeding - and from what I understand, this paper comes to the conclusion that it probably does not.
Whereas there are only about two dozen resident adult Lemons in Moorea, the species has evolved patterns to mitigate the according risk of inbreeding insofar as the Sharks will travel to both mate and pup (= migration), and that some individuals will travel to take residence in other islands (= dispersal), all of which is conducive to gene flow. Having said that, the degree of inbreeding of the Lemons in French Polynesia remains never the less relatively high, this likely due to small overall numbers and the relatively high isolation between islands and between archipelagos.
And the take away message after this rather epic 5y investigation?
I believe it boils down to this - and I trust that Johann will correct me if not.
Like Juerg's Fiji paper, it once again confirms that provisioned Sharks appear to disperse normally, or as Juerg puts it, that Chumming and food provisioning are unlikely
to fundamentally change movement patterns at large spatial and temporal
scales, and seem to only have a minor impact on the behaviour of large
predatory sharks; hence, the creation of behavioural effects at the
ecosystem level seems unlikely.
Obviously, this is the one aspect I'm most concerned about - and I sure hope that Johann will agree with this conclusion!
That said, Lemons are not Bulls and French Polynesia is not Fiji. There remain some local effects that are a possible cause for concern, foremost of which the observed increased residency that could eventually result in lower numbers of Lemons dispersing which in this generally small population might have a significant negative effect on gene flow and thus the fitness of that local population.
The second possibly negative effect is the observed increased aggression. I continue to question whether the observed increased brawling among male Lemons is really relevant in view of the animals' quasi magical healing powers. But what is certainly worrisome are the reports of increased strikes on humans, see the testimony by Moorea Natural Diver Lover in the comments section here. To me, they are the direct result of poor procedures, foremost of which the surface feeding mentioned here. However Johann tells me that there's only one remaining operator that feeds the Sharks, so maybe that problem has been resolved - that is, provided that the operator is taking the necessary precautions which is not necessarily a given and certainly worth keeping an eye on!
All-in-all, a really brilliant job, and big kudos to everybody involved!
Remember how everyone wanted to be a marine biologist at some point
while growing up? Well, this video pays tribute to the wonderful and
REAL world of marine biology. (Also, please keep in mind, we are
actually working in these clips!) Please share this video,
especially with people who may consider marine science as a career!
Hopefully, this makes their decision a little easier, and we are always
recruiting :) This video would not have been possible were it not
for the amazing people (many of whom are featured here) that make
working as a field researcher on the island of Moorea, French Polynesia
so special an experience. Featured researchers are studying
various aspects of coral reef community ecology, and they are based out
of the University of Florida, California State University-Northridge,
the University of California-Santa Barbara, and Victoria University of
Wellington. For more information, please visit: http://michaelgil.wordpress.com
Actually, it's quite the contrary! I must say, I'm increasingly impressed by the quality of people who have decided to come pay us a visit as of late. Maybe it's the incessant ranting on this blog or maybe it's even the disclaimer at the bottom of our home page - but the trend is unequivocal: the activists and adrenaline hunters are thankfully going somewhere else and being replaced by truly remarkable personalities who combine a passion for Sharks with solid knowledge and a refreshingly pragmatic and solution-oriented approach to Shark conservation.
Case in point, Erich Clua. He popped in the other day and what ensued, apart from the inevitable bonding of Shark aficionados and some stellar pictures, see on top, was a remarkable discussion about the pros and cons of baited Shark diving. Eric is of course none other than the lead author of the Lemon feeding paper and French on top of that, and I was bracing myself for an explosion of Gallic outrage about the irreverence of my comments. But I must really say, Eric was nothing but constructive and genuinely interested in feedback - and yes, it may have helped that I know French Polynesian Shark diving politics in general and the Moorea Lemon Shark dive in particular, and that I was able to converse in passable French! :)
But I'm digressing as usual. The fact is that Eric is a passionate Shark diver with a big heart for Shark conservation, and that he conducts fantastic Shark research in New Caledonia and in French Polynesia - in brief, the exact opposite of those bloviating Sesselfurzer! Despite being professionally active in another field, he is also a big honcho at the SPC and thus in an ideal position for furthering and disseminating desperately needed modern Shark conservation concepts (= forget the quotas: don't kill them at all!) across the SOPAC.
This is one of the many reasons for why I like his article. It's included in the SPC's Fisheries Newsletter and has thus been read by policymakers across the Pacific. In case anybody should have forgotten, it is them and not the clamoring conservationists who will ultimately draft, or not draft any legislation protecting the marine resources we are so passionate about, and it is thus them we need to convince! My personal wish: that it may finally spawn some reflection within the arcane halls of the SPTO and of SPREP whose representatives have so far displayed an equally irritating and ignorant aversion for our industry, this despite of the obvious benefits for both tourism and marine conservation.
Any caveats? Most certainly! :) They center around the assertion that feeding quickly leads to dependence when food is easily available, as well as to sharks’ becoming accustomed to the presence of humans. Humans are soon associated with food and otherwise wary, distant sharks no longer hesitate in approaching humans and even entering into close contact with them. This significantly heightens the risk of accidental biting (e.g. a shark biting a diver’s limb that it mistakes for food) or intentional biting out of domination or territorial instincts. Re-read this and you will know where I'm coming from on this topic: there is ZERO evidence that Sharks become dependent on handouts; and whereas I fully concur that the risk of bites (mind you: during the feed!) does indeed increase, I miss the unequivocal statement that the remedy is to implement better procedures, not to prohibit or demonize the feeding per se.
Examples? The food is then released, and a hectic swirl ensues equals dumping which can result in feeding frenzies. We advocate always keeping control of the bait (e.g. by hand feeding) or only releasing the bait once the clients have left. Equally, we advocate single user sites where the animals are being conditioned to an always uniform and thus predictable routine. French Polynesian Shark feeding sites are however generally free-for-alls where different operators try to one-up their competitors in macho showmanship, which is a notorious problem in Moorea where the Lemons have even been lured to the surface by snorkeling boats. In brief: if Moorea wants to continue enjoying the benefits of a thriving Shark tourism industry, somebody there has to put a stop to the shenanigans. Eric being a client of those dive ops cannot quite say it that openly - but I am quite certain that he concurs!
And what about the increased dependency and aggression? We do not at all have the same experience. Our data clearly show that there is no increased residency in our Bulls, as despite of the ever increasing numbers, single individual animals only pop by for short periods of time, weeks at best, but spend the majority of their life elsewhere, likely roaming for food; also, they leave during the mating season and we are thus not witnessing their possibly heightened aggression like what is happening with those male Lemons. But as always, granted, those are completely different Sharks, at a completely different site, with completely different procedures!
Long story short? I really have to commend Eric. The article is interesting, very much in favor of Shark conservation and the Shark diving industry and refreshingly nuanced where it touches upon the more controversial aspects. Very well done indeed!
As he writes in a recent message: Nous jouons dans la même équipe!
This is a Sicklefin Lemon - forget the fins: notice the black dot on the nose? That's how you identify them!
Check this out.
This is another real interesting interview by WhySharksMatter . David: well done & keep ‘em coming – so far, yer getting 10 out of 10!
Very cool! Monsieur Clua is of course non other that the co-author of the Moorea Lemon Shark feeding paper and consequently, I continue to sense the same anti-feeding bias. But at the same time, we learn that there are three dive ops feeding on that site, meaning that as expected, it is a multi-user site with all the resulting problems, and Johann Mourier’s answer on our Facebook stating that The feeding practices implemented by some diving center(for example feeding sharks from the surface) have led to a change in shark's behaviour, with bottom living lemons starting to come on the surface further leads me to believe that the real problem (if there is one) may well be procedures-related as I assumed in my post – and if so: everybody is herewith invited to come see what we do here, FOC, and discuss the possible implications for French Polynesia!
I actually tried to have that conversation there and although we are friends and everybody seemed interested, it was equally clear that nobody believed that the different interests would ever come around a table and agree on anything – I may add, very much like here in Fiji!
Anyway, the info about the value of Sharks was really interesting! I remember seeing a direct value of approx USD 20,000 per shark per year from the Maldives, one operator in SA reports a value of approx USD 15,000 and the value of Shark tourism to the Bahamas is apparently USD 78m per year. Now, Clua postulates USD 50,000 per Shark per year for Moorea’s Lemons which is great – and also an indication of the price level of that particular corner of paradise!
Here’s the back-of-the-envelope calculation for Fiji. We turn over FJD 1m with two boats, and it’s fair to assume that the guys down the road turn around half of that with one boat. Let’s also assume that all of it gets re-invested in Fiji, which is what we do. Add the ancillary revenues as in flights, hospitality, restaurants, cabs, excursions, souvenirs etc and assume that the ratio may well be 2:1 (it is probably higher) – makes FJD 4.5m in total which two small dive ops earn with approx 100 regular Sharks. Thus, the direct value of one of those Sharks to the Fiji economy is FJD 45,000 or USD 23,000 for every year it lives – as opposed to 300 bucks for its fins, once! Pretty darn impressive, huh!
Clua also mentions the indirect value of Sharks to the Country citing improved fisheries etc. Absolutely!
In my conversations with Government, I say this. Some Sharks (not all: some are clearly mesopredators that would wreak havoc on the lower throphic levels if their population were not held in check), notably the larger predatory ones are probably keystone species that have a profound effect on the health of the reefs, meaning that if they were removed, the reef ecosystems could well collapse.
With Fiji being an island state, it is fair to assume that the principal, if not the only reason why tourists come and visit are its pristine reefs and waters, meaning that if the reefs were to be degraded, Fiji (and French Polynesia, and the Bahamas, and the Maldives, and Palau!) could kiss their tourism industry goodbye! That’s millions upon millions of dollars, often the country’s principal sector of GDP and source of foreign exchange!
Keep this in mind next time you talk about Sharks, OK?
May Monsieur Mourier have an agenda?
Check out his pre-emptive statements about Shark feeding here.
Then, compare to excerpts of this new paper he has co-authored.
Behavioural response of the sicklefin lemon shark Negaprion acutidens to underwater feeding for ecotourism purposes Eric Clua*, Nicolas Buray, Pierre Legendre, Johann Mourier, Serge Planes *Email: EricC@spc.int
ABSTRACT: 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 one around the world in spite of 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 months, 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 in-and-out movements of some males and females, probably related to mating, the general trend is that residency significantly increased during the study, particularly in males, showing a risk of inbreeding due to the reduction of shark mobility. Intra and inter-specific aggression was also witnessed, leading to an increased risk of potentially severe bites on 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.
From the paper
INTRODUCTION
Large predators, which are potentially dangerous to humans and often feared, account for a substantial proportion of ecotourism activities based on animal sightings.However, because of their generally elusive nature and locally low population densities, such predators are often difficult to observe. Sharks are shy animals (Bres 1993), and provisioning is necessary to produce reliable and impressive aggregations of animals. The last decade has seen tremendous development of ecotourism based on the sighting of top marine predators (Orams 2002, Topelko & Dearden 2005). The practice of shark-feeding is widespread throughout the tropical and subtropical seas of the world, e.g. in the Bahamas, Fiji, South Africa, Australia and French Polynesia, and it is becoming controversial, with little consensus about how it should be managed.
Deliberate and long-term shark-feeding is suspected to generate problems for both animals and humans (Dobson 2006, Newsome & Rodger 2008).It may alter the natural behavioural patterns of sharks, generating biological (for the animal themselves) and ecological (for the ecosystem) effects. Provisioning may cause habituation to human contact and increase aggression towards humans by associating divers with food (Burgess 1998, Orams 2002). However, feeding wildlife can be a positive tool for assisting in the conservation of vulnerable and endangered species, through attaching economic value to wildlife and educating tourists about the need for conservation (Bookbinder et al. 1998, Halpenny 2003); it can also increase the probability of a shark encountering a partner as a result of aggregation (Orams 2002).
Despite the controversy, few, if any, comprehensive reports have measured the impact of shark-feeding, which is now widespread and growing around the world. To date, studies have been conducted on the effect of chumming on white shark Carcharodon carcharias in South Africa (Johnson & Kock 2006, Laroche et al. 2007), as well as sandbar Carcharhinus plumbeus and Galapagos C. galapagensis sharks in Hawaii (Meyer et al. 2009).These studies all concluded that moderate levels of provisioning of cage-diving ecotourism probably had a minor impact on the behaviour of the sharks and no risk of increased attacks on humans in adjacent areas.
In South Africa, Johnson & Kock (2006) showed that conditioning only arises if white sharks gain significant and predictable food rewards, which only happens if operators contravene permit regulations prohibiting intentional feeding of sharks.White sharks are lured to the boat with baits (typically, mashed sardines and fish oil; Laroche et al. 2007) that are significantly different from their usual prey in the area, Cape fur seals Arctocephalus pusillus pusillus (Ferreira & Ferreira 1996).
In Hawaii, Meyer et al. (2009) showed that cage-diving activities did not increase the number of attacks on humans, probably due to the fact that the shark tours use a small amount of fish scraps, mimicking the activities of crab fishing vessels which have been operating in the same area for over 40 yr. In both cases, while some food is used to attract sharks to the cages for observation and photography, the quantities involved are small, so this activity cannot be considered as real ‘provisioning’.
Light baiting is also used at Aliwal Shoal (South Africa) for attracting tiger sharks Galeocerdo cuvier and allowing encounters with snorkelers in open water (Dicken & Hosking 2009).
However, the available scientific data focus on the economic value of the recreational activity, and do not address its effects on the behaviour of these potentially dangerous sharks (ISAF 2010).Bull sharks Carcharhinus leucas, another dangerous species (ISAF 2010), have been attracted to an ecotourism site in Beqa (Fiji Islands) since 2002 through a real feeding and conditioning process based on the release of several tuna heads during each dive (E. Clua pers. obs.); here again, however, the only data provided are socio-economic (Brunnschweiler 2010), with no reference to the biological issues of provisioning of carnivorous animals.
Given the controversial nature of shark-feeding, there is a critical need for empirical studies that focus on potentially dangerous sharks, and address both the potential disruption of their natural behaviour, which underpins their resilience, and the increasing risk of fatal attacks on humans (Garrod & Wilson 2006).
In French Polynesia, sharks are fed daily during diving activities.The main species involved, the sicklefin lemon shark Negaprion acutidens, can reach over 3 m in length and is considered to be potentially dangerous to humans (Maillaud & Van Grevelynghe 2005, ISAF 2010). This coastal shark is widely distributed in the Indo-Pacific, from Eastern Africa to French Polynesia. However, very little is known about the ecology of the sicklefin lemon shark in the Central Pacific. Despite its commercial value (Compagno 1984), only a few studies have been conducted in the Indian Ocean (Stevens 1984) and in Western Australia (White et al. 2004) besides a recent global genetic study (Schultz et al. 2008). The ecology of its sister species, the Atlantic lemon shark N. brevirostris, has been well documented during past decades (Gruber 1982, Chapman et al. 2009), mostly in the central Western Atlantic Ocean. However, while its early life has been extensively studied (Morrissey & Gruber 1993, DiBattista et al. 2007), very little is known about the adult stages of N. brevirostris and even less about N. acutidens.
Moorea Island (French Polynesia) is among the few locations worldwide where it is possible and feasible to have daily encounters with several wild adult sicklefin lemon sharks in their natural environment. This characteristic provided us with an opportunity to investigate the behaviour and residency pattern of an adult population of this reef shark species through daily underwater observations at a provisioning tourism location. Here, we describe the population size and structure of this species, aggregated for ecotourism purposes at a site on the northern outer reef of Moorea Island. We divided the population into co-occurrence groups and describe the residence patterns and behaviour of these groups. We also tested the hypothesis that shark-feeding increases the fidelity of lemon sharks to the site, and discuss the potential long-term effects on population resilience and behaviour, including the risk of increased interactions with humans. From the
DISCUSSION
….Assuming similarity in the natural behaviour of these 2 sister species (Editor: Common and Sicklefin Lemon Sharks), our findings could be linked to an aggregating effect of shark-feeding, which decreases the mobility of animals, mainly the males, and may contribute to increased inbreeding. This trend may lead to long-term loss of genetic variability in the Polynesian lemon shark populations, even though natural philopatry in N. acutidens, which would have been a detrimental factor, seems to be low (Schultz et al. 2008).
Increasing residency was a general trend for the shark population. For all groups except Group B, which was composed of animals that disappeared, the linear regressions had positive slopes (Fig. 4), indicating an increase in shark abundance over time, and their site fidelity increased over the 44 mo, particularly for the ‘resident’ subgroups, C1 and C2 (Table 1). This means that, despite some sharks leaving and othersarriving, the number of days with sharks present and the number of sharks at the site both increased. This trend is explained by the increased attraction of sharks by provisioning, suggesting that learning plays a strong role in optimising their food search (Guttridge et al. 2009). Our findings are consistent with similar situations where other elasmobranchs (rays) learned to associate specific locations with food rewards, with detrimental effects on their behaviour, and indirect effects on the surrounding marine ecosystems, leading to the concept of an ‘ecological trap’ (Corcoran 2006, Gaspar et al. 2008, Semeniuk & Rothley 2008).
In the case of lemon sharks, their increased site fidelity can have a negative effect on gene flow, as mentioned previously, and can also affect their role as top predators in the area, as shown for top terrestrial predators such as dragons Varanus komodoensis in the Komodo National Park, where provisioning was eventually banned (Walpole 2001).
Among the negative effects, we observed intraspecific interactions generated by the provision of a limited amount of food. Not all sharks present during a dive acquired food, and this resulted in exacerbated competition among the animals. This pattern can lead to increasing the number of intraspecific dominance actions and the aggression of sharks to acquire food (Ritter 2001), as shown for rays (Semeniuk & Rothley 2008). Dominance is often driven by the size (length) of the sharks in social groups (Allee & Dickinson 1954, Myrberg & Gruber 1974). During several feeding sessions, the largest resident male, M04, appeared to be the most inquisitive, approaching the divers closer than any other individual did. Since males M07 and M18 were dominant in 2005, M04 definitely acquired increasing dominance behaviour with respect to other individuals, which turned into deliberate aggression towards other males when several of them were present.As was previously observed in 2005 for its 2 predecessors, from 2006 onwards M04 often arrived in the morning with fresh scars or notches that can be attributed to intraspecific fights (N. Buray pers. obs.). Aggression increased significantly when resident males came back to the feeding site after the mating period, probably in the context of a reorganisation of the hierarchy, as shown by serious wounds on males that were quite different in their severity and locations from those inflicted on females during mating (Fig. 5).
In natural conditions, sicklefin lemon sharks cannot be considered a gregarious species (Stevens 1984), except during the mating period, and animals usually feed separately.Therefore, intraspecific aggression linked to the feeding process, even though natural among carnivorous animals, can be interpreted as deviant behaviour, exacerbated by human activity.Although managers may consider this process of increasing intraspecific aggression to be acceptable among sharks, it represents a real issue regarding the safety of divers for whom the risk of accidental bites has increased critically (Burgess 1998).Between 1979 and 2001, 47% of shark bites in French Polynesia were experienced in the context of shark-feeding activities (Maillaud & Van Grevelynghe 2005). Although anecdotal, this was confirmed by a serious bite by shark M04 on the left hand, which was not holding any food, of the diver doing the feeding in January 2006 (N. Buray pers. obs.).
The results of this study indicate that in spite of the provisioning activity, several male and female sicklefin sharks seem to have left the study site while others came back to it for mating.This positive aspect from the perspective of maintaining gene flow between this shark population and adjacent ones is mitigated by the increasing pattern of residency for the overall population during the study. At present, the population seems to be a balanced mix of resident and non-resident individuals, which favours population mixing. However, if the resident sharks increase their numbers and their attachment to the feeding site, group living can generate costs for animals which are normally solitary foragers, such as injuries, predation, increased stress hormone levels and exposure to parasites due to increased transmission rates between individuals (Semeniuk & Rothley 2008).If supplemental feeding can be perceived as an artificial support to sharks by providing easy-to-access resources (Milazzo et al. 2006, Laroche et al. 2007), and can allow increasing energy allocation to other fitness-related activities such as rest and reproduction (Orams 2002), long-term unnatural aggregation can also have long-term fitness consequences for the population. Because the studied population is small, daily aggregations at the same location could result in increased social interactions and increased mating between close relatives, reinforcing the risk of inbreeding. As lemon sharks are known for their polyandry (Feldheim et al. 2004), the potential negative effect on gene flow linked to the increasing residency pattern might be buffered by the multiple paternity process; this needs to be thoroughly monitored.
This factor, added to the development of aggression and incremental risk of accidental bites to divers, should lead managers to seriously consider a revision of the regulations on shark-feeding in French Polynesia in order to reduce these risks.An annual cessation of the feeding activity for several months, preferably encompassing the mating period, is an obvious solution.Whereas our study allowed us to draw these preliminary conclusions, additional field investigations are required to better understand the long-term effects of provisioning on shark populations. Further work may also enable us to better understand the risks induced by feeding predators.
Hmmmmmm…
Quick ‘n dirty assessment: interesting - but both prejudiced and highly speculative!
But first things first: this is what I like.
Scientists are finally discovering the Shark feeding industry and publishing a first set of baseline studies, of which this is a (I believe: rather poor) example. And although I do not concur with the conclusions, see below, I do commend the authors for having taken the time to compile and analyze a long term set of data. As the always brilliant CJA Bradshaw remarks, monitoring has long been the ugly cousin of the fashionable experimenting and is only now being recognized as an invaluable tool for trying to decipher complex systems where causal relationships are not immediate and thus difficult to manipulate selectively.
Which brings me straight to my principal critique.
Where is the control group, as in a comparable group of Lemons that are not being fed? If they got nothing to compare them to: how can the authors postulate that any of the described phenomena are caused directly by the human interference and not due to chance variability, or to natural fluctuations in population, or to climate fluctuations like ENSO or the like?
But let’s quickly examine the allegations.
The observed increased residency may lead to reduced gene flow and inbreeding.
Indeed, maybe! But many Shark species, among which Lemons, do wander off during mating season and indeed, so did the studied animals! The increased residency during the remainder of the year is utterly irrelevant in terms of gene flow as the animals do not mate during that time – or are we to believe that Lemon Sharks may engage in protracted dating prior to having sex?
Plus – was the increased residency the direct consequence of the feeding, see above?
Increased intra-specific aggression.
Here, the authors blame the limited amount of food leading to exarcerbated competition; and on the other hand, they seem to postulate (?) that a higher concentration of resident Sharks led to more hierarchical fights and subsequent wounds in males.
Probably! But having witnessed how fast Sharks recover from horrific wounds contracted during the mating season, what is the point? Did any of the bitten Sharks die or end up being permanently inconvenienced as a consequence - and how does that compare to the “natural” mortality and/or bite frequency of non fed Lemon Sharks?
Plus, what’s that tale about M04? M04 often arrived in the morning with fresh scars or notches (that were hence not contracted during feeding time!) that can be attributed to intraspecific fights (N. Buray pers. obs.). Interesting – but is it science?
Knowing that all individual Sharks have different characters: was he maybe just a notorious brawler – and not a very successful one since it was him, the supposedly dominant Shark, coming back with those wounds and not his assumed victims? And who did he brawl with: females or males?
Increased inter-specific aggression - what is the other species: humans?
If so, we learn that 47% of shark bites in French Polynesia occur during Shark feeds and that M04 bit a feeder in the hand. Both, we learn, prove that the risk of accidental bites has increased critically.
Well, gee, what a mind-boggling insight! Tremendous development of shark dives is leading to more bites!
I’ve blogged about it in extensohere and don’t need to repeat myself more than that: the precondition for a Shark bite is that a human and a Shark be in the same place at the same time (hellooooo…) and thus, feeding sharks does indeed increase the risk of getting bitten and more Shark feeds will indeed lead to more bites!
This is so trivial, it is painful!
By the same token, the act of commuting in aeroplanes increases the risk of fatal plane crashes - yes, believe it or not: it does!!!
So going back to square one: do we prohibit aviation as a consequence? No, we ask that anybody engaging in the activity, especially commercially, follow a regimen of strict safety protocols!
Right?
Now, it just so happen that I’ve done a multitude of Shark dives in French Polynesia.
Many of them were Shark feeds with mainly Greys and Silvertips - and yes, I’ve also witnessed several of the Moorea Lemon Shark feeds.
Any Shark bites?
Certainly: four of them, one by a Silvertip and three by Grey Reefs!
The cause: multi-user sites combined with Gallic panache and improvisation: poor Shark diving briefings leading to unpredictable behavior of the clients, ever changing procedures and feeders, creative chaos and heaps of bravado, zero protection of the feeders and clients alike – in brief, the recipe for certain disaster!
With that in mind, the described bite comes at no surprise whatsoever!
BUT!
Was that bite by M04 really aggression – and if so, due to what? Did the behavior of the feeder piss off the Shark? Did the Shark mistake him for a competitor? Is aggression really the most plausible explanation?
Here in Fiji, all of our clients have to wear dark gloves. The reason is that anybody without gloves will get nailed by the ever greedy Giant Trevally and Red Bass who mistake the pasty hands sticking out of dark wetsuits for bait. This is not aggression, this is a mistake!
Would it not be much more plausible to assume that M04 might have made the exact same mistake when in a hurry due to a competitive situation?
Bull Sharks are not Sicklefin Lemons and anybody who knows about Sharks knows that different Shark species have very different behavioral traits and that one cannot make generic statements across species - and certainly not make comparisons to, of all animals, Komodo Dragons!
Keeping in mind the above caveat, this is what we do in Fiji in order to increase the safety of everybody:
- This is a one operator site, meaning that we can enforce a uniform protocol that is always highly predictable – for the animals, not us!
- By the same token, the people feeding are always the same, to the point that they have developed personal relationships with individual Sharks
- Feeders wear chain mail gloves and clients, full body dark wetsuits and black gloves
- There is separation between the large Bull Sharks and the customers (remember the precondition above!)
- There are extensive dive briefings so that the clients know exactly how to behave and don’t startle the animals
- There is ample food and the animals are conditioned to follow a set routine, meaning that we are trying to minimize competitive pressure. We also always control the amount of food being introduced, meaning that when we sense any incipient tension, we can discontinue the feed and wait until everybody has calmed down again.
Could some of it be replicated in Moorea! Sure!
Long story short: the obvious solutionis not the annual cessation of the feeding activity for several months that implies the necessity to re-establish the feed, the relationships and the training of the animals - it is to improve the feeding protocols!
As to the other grievances about inbreeding and intra-specific aggression: not with our Bulls!
We’ve been keeping highly detailed tabs for 7 years now and none of the Bulls has taken up residency, let alone established a territory necessitating defense against conspecifics.
Instead, although the numbers continue to increase, we’re being faced with a continuous rotation of individuals who clearly lead a free life and are not dependent on Shark Reef for sustenance. Plus, they all vanish during the mating season which is a good indication for them doing plenty of walkabout and mixing of gene pools once they get horny!
The tally:
Bulls biting feeders: zero;
Bulls biting clients: zero;
Bulls biting Bulls: one documented case (we always have at least one camera rolling) where two homed in on a Tuna head and one very obviously missed the head and bit the other – yes, camera rolling! We have certainly never witnessed a single case of a Bull Shark resorting to biting in order to assert its dominance, and this in thousands of Shark dives – but then again, it’s a different species.
Fatalities among our 100 individually named animals, of a total of approx 300: only Jaws who has been missing since 2006.
All others are friendly, well fed and above all, locally protected - and I believe, perfectly happy!
Hence, what is the relevance of this paper to what we do and to Shark feeding in general?
You be the judge of that.
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