I just love this clip of that little juvenile Lemon.
Source - Enjoy!
Showing posts with label Lemon Sharks. Show all posts
Showing posts with label Lemon Sharks. Show all posts
Wednesday, April 04, 2018
Determined!
I just love this clip of that little juvenile Lemon.
Source - Enjoy!
Sunday, September 24, 2017
Lemon Sharks: This has happened in Florida!
Bingo, and I cite,
This Final Amendment updates Atlantic HMS essential fish habitat (EFH) based on new scientific evidence or other information and following the EFH delineation methodology established in Amendment 1 to the 2006 Consolidated Atlantic HMS FMP (Amendment 1); updates and considers new habitat areas of particular concern (HAPCs) for Atlantic HMS based on new information, as warranted;
....
In addition to identifying EFH, NMFS or Regional Fishery Management Councils may designate HAPCs where appropriate.
The purpose of a HAPC is to focus conservation efforts on localized areas within EFH that are vulnerable to degradation or are especially important ecologically for managed species.
EFH regulatory guidelines encourage the Regional Fishery Management Councils and NMFS to identify HAPCs based on one or more of the following considerations (§ 600.815(a)(8)):
....
- The importance of the ecological function provided by the habitat;
- the extent to which the habitat is sensitive to human-induced environmental degradation;
- whether, and to what extent, development activities are, or will be, stressing the habitat type;
- and/or, the rarity of the habitat type.
Amendment 10 creates (a) new HAPC for juvenile and adult lemon sharks off southeastern Florida between Cape Canaveral and Jupiter inlet.
The new HAPC for juvenile and adult lemon sharks is based upon tagging studies and public comments received that expressed concern about protection of habitat in locations where aggregations of lemon sharks are known to occur.
.....
Dated: September 1, 2017.
Samuel D. Rauch III, Deputy Assistant Administrator for Regulatory Programs, National Marine Fisheries Service.
Remember the whole drama back then in late 2015?
Whereas the clamoring by the troglodytes and the shark girl has achieved nothing other than pissing off the fishing lobby and the authorities, and has led to the introduction of a Federal Shark diving ban by the Florida Senators as a consequence, other people have been quietly looking for a solution - not for camera or applause or perceived fame but only for the sake of the animals.
This may well be that solution.
The Lemon Shark aggregation happens mostly within protected State waters but extends to unprotected Federal waters, and this designation as habitat area of particular concern can now hopefully lead to a temporary fishing ban during the aggregation season from December to April - along with hopefully, less disturbance by pesky divers!
I say, well done ladies and gentlemen!
You know who you are!
Monday, December 16, 2013
Natal Philopatry in Lemon Sharks - Paper!
Time for some Hi-Fives! Source.
Now THIS is real science!
No wonder as starting with the Grand Mufti himself, the list of authors reads like the who's who of Shark research - and with the data spanning a whopping 17 years, this is nothing short of epic!
All I can say is, I'm deeply impressed!
Looks like Lemon Sharks not only go back and give birth in the same nurseries (= reproductive philatropy) like the Moorea Blacktips, but that those nurseries are the very where they themselves were born (= natal philopatry or natal homing), like e.g. Salmon or Turtles! This has immediate implications for conservation insofar as it mandates special efforts to protect those nurseries.
Nice synopses here, here and here - and here's a video.
And the Bull Sharks?
Mark has already published evidence for reproductive philopatry of Bull Sharks in Australia, and one of the aims of our new research projects with Projects Abroad will be to check whether this is equally the case for our Fiji Bull Sharks.
So keep watching this space!
And the Bull Sharks?
Mark has already published evidence for reproductive philopatry of Bull Sharks in Australia, and one of the aims of our new research projects with Projects Abroad will be to check whether this is equally the case for our Fiji Bull Sharks.
So keep watching this space!
Anyway, great job!
Enjoy!
Wednesday, October 02, 2013
In Dangerous Waters!
Cute.
Nice idea, nice execution considering the likely reduced budget, some mild trichage and even an attempt at a veritable nuit américaine.
And - one glaring factual mistake!
Did you notice?
Did you notice?
Anyway, nice job.
Enjoy!
Monday, September 23, 2013
Florida Lemons - last Day for Comments!
Please post you comment here.
Background and great template here.
Whatever you other statements, it is important that you state that you oppose the opening date of January 1 and ask that it be returned back to July like before.
Do not copy/paste this crap.
Thank you!
Friday, September 20, 2013
Florida Lemons - epic Comment!
Wow wow wow!
You really must read this!
Rarely if ever have I read such an passionate, intelligent, informed and balanced statement in favor of the sustainable and smart management of a Shark fishery.
Rarely if ever have I read such an passionate, intelligent, informed and balanced statement in favor of the sustainable and smart management of a Shark fishery.
And great name, too! :)
Huge congratulations Mike!
Thursday, September 19, 2013
Florida Lemons - great Instructions by Shark Savers!
Excellent stuff!
Read this.
It once again describes the problem and it also provides for a great template for any comments you may want to post to the relevant NOAA page.
The all-important statement is
I oppose the proposed rule that the 2014 Atlantic Shark Commercial Fishing Season open on January 1 based on its negative effect on the regional lemon shark aggregation off the coast of Jupiter, Florida. To relieve fishing pressure on a highly vulnerable, breeding population of lemon sharks, I request the fishing season revert to the original opening date of July 1st, after the completion of the annual birth cycle and when the seasonal distribution of lemon sharks is less concentrated geographically.
After which you can add whatever you wish.
Without the reference to changing the season back to July, your comment is basically worthless - and having checked, too many of the comments are still not much more than generic sharkitarian fluff.
That is step one.
Step two should consist in advocating a seasonal fishing closure and/or gear ban around the Jupiter aggregation site, much like what is being done for the Fish spawning aggregations. Like there, the rationale would be that targeting the breeding stock of a particular population is generally bad for the fishery depending on it.
Any takers?
Comments close on Monday September 23.
Wednesday, September 18, 2013
Lemons - Action Alert!
This is urgent.
Please read this post.
Those Lemons are the very same individuals one experiences at Tiger Beach and throughout the Bahamas but also along the whole eastern coast of the US from Florida all the way up to the Carolinas. They are particularly vulnerable to over-exploitation when they aggregate in spring off Jupiter, and although they are protected in Florida, the aggregation straddles the boundary between state and federal waters and is thus subjected to federal regulations.
The numbers have already been declining substantially since 2007 as regulatory measures implemented in 2006 to protect Sandbar Sharks have increased the fishing pressure on other large Sharks including those Lemons - and last year's change of the opening date for commercial fishing to January 1st appears to have had a devastating effect.
Please post your comment here.
In doing so, please follow the suggestions in the post linked above - comments must be pertinent to this specific issue and basically recommend that the opening of the 2014 Atlantic Shark Commercial Fishing Season be moved back from January to July.
With that in mind, please refrain from posting statements like Please help support anything and everything that will help keep shark populations healthy. We love our sharks. as they are of no use whatsoever. This on the other hand is an excellent comment.
With that in mind, please refrain from posting statements like Please help support anything and everything that will help keep shark populations healthy. We love our sharks. as they are of no use whatsoever. This on the other hand is an excellent comment.
Should you not know what to write, e-mail Hannah and she will be happy to assist you.
Comments close on September 23.
Thank you!
Sunday, September 16, 2012
Learning in Sharks - new Paper!
From the paper.
Abstract
Social learning is taxonomically widespread and can provide distinct behavioural advantages, such as in finding food or avoiding predators more efficiently.
Although extensively studied in bony fishes, no such empirical evidence exists for cartilaginous fishes.
Our aim in this study was to experimentally investigate the social learning capabilities of juvenile lemon sharks, Negaprion brevirostris. We designed a novel food task, where sharks were required to enter a start zone and subsequently make physical contact with a target in order to receive a food reward.
Fig. 1 Set-up of social learning experiment: a positions and measurements of zones, target and reward; b schematic of the target mechanism showing covered and exposed position as well as side and front views; and c steps of the food task or trial - click for detail!
Naive sharks were then able to interact with and observe (a) pre-trained sharks, that is, 'demonstrators', or (b) sharks with no previous experience, that is, 'sham demonstrators'.On completion, observer sharks were then isolated and tested individually in a similar task.During the exposure phase observers paired with 'demonstrator' sharks performed a greater number of task-related behaviours and made significantly more transitions from the start zone to the target, than observers paired with 'sham demonstrators'. When tested in isolation, observers previously paired with 'demonstrator' sharks completed a greater number of trials and made contact with the target significantly more often than observers previously paired with 'sham demonstrators'.Such experience also tended to result in faster overall task performance.
Fig. 5 Testing phase: median (±interquartile range) number of physical contacts made with the target and the target cover by individual observer sharks previously paired with demonstrators (D) or sham demonstrators (SD). P\0.05 in both cases, Wilcoxon signed-ranks test, n = 5 - click for detail!
These results indicate that juvenile lemon sharks, like numerous other animals, are capable of using socially derived information to learn about novel features in their environment.
The results likely have important implications for behavioural processes, ecotourism and fisheries.From the DiscussionIt has previously been hypothesised that sharks can form groups for increased foraging opportunities (Jacoby et al. 2011) and that sharks exhibiting feeding behaviour attract nearby conspecifics or heterospecifics (Myrberg et al. 1969; Bres 1993; Klimley et al. 2001). Although we did not determine specific social learning processes, our findings empirically demonstrate the sensitivity to, and likely importance of, social cues in sharks.These and other recent findings that stress the importance of social behaviour to the efficacy of shark deterrents (O’Connell et al. 2011; Robbins et al. 2011) emphasise the need for further experimentation on how changes in sharks social environment (presence of competing or informed conspecifics) might affect their foraging strategies or performance and exploitation of a novel food source.
As I said, great job - which is of course no wonder!
After all, Tristan is one of Doc's disciples and the whole thing did happen in Bimini as part of a wider endeavor and very much under the supervision and leadership, but undoubtedly also scathing criticism by the great man himself! This is your classical behavioral experiment aimed as testing a previously formulated hypothesis, and this thankfully (and very much unsurprisingly!) involving a control group - as it should be!
Of course we in the Industry knew that already.
There are plenty of examples of Sharks appearing to learn from their conspecifics (and who knows, maybe other species as well?) during baited dives, this from species as vastly different as the Whale Sharks in Oslob or Cendrawasih Bay to, it appears, the Sicklefin Lemons in Moorea.
Here are some examples by Doc himself.
We know from simple observations that throwing a piece of bait to a naïve lemon shark will take about three pieces for that shark to get the idea that the sound of a splash means that food has landed in the water near it. Then you see other lemon sharks watch the smart one and pick it up right away...splash=food.Indeed we do!
This is especially so with the larger reef sharks.
It is easy to tell a new, inexperienced (new comer) reef shark from the experienced group. tThe newcomer has no clue when a piece of food is thrown a foot in front of its nose. It just swims on by. A trained shark however will have already associated food=splash and will immediately turn, orient to the sound and gobble up the piece. When the new comer watches the trained group orienting to the sound of bait hitting the water it picks it up immediately and gets it from there on. Additionally the other trained reef shark appear to the sound of the boat when we anchor up at the feeding site with no bait.
They are smart animals but you already know that.
We have observed learning in our social Reef Blacktips but above all, in our Bulls where we are convinced that the fact that the newbies follow the correct feeding protocols from the get-go is due to the fact that they have learned to behave correctly by observing the experienced old-timers!
So, what do the findings of the paper mean?
Do they prove that Sharks are intelligent?
No they do not!
They show that juvenile (= an adjective) Lemon Sharks (= a species) are able to learn a task by observing other juvenile Lemons and, as Doc tells me, that they could learn faster than rabbits or cats (= other species) on a conditioned response and could recall the response up to a year.
And what about the other Sharks? No idea!
Hell we don't even know whether those findings extend to adult Lemon Sharks, see the various hypotheses about slower and/or different learning that are being put forth for humans! Maybe Sharks, too, get more set in their ways and are less prone to experimenting as they grow up? I'm asking this as some of our old ladies do things in always the exact same way, likely because they have learned that it works!
My hunch is that if tested, different species will show different results.
And I'm also quite confident that there will be differences at an individual level - and possibly even at the level of gender or life stages, who knows!
I'm also expecting that the results will correlate with the extent to which those species are social (remember this is about social learning - which of course begs the question whether our Bulls are social!), but possibly, also with the extent to which learning is a useful strategy considering the specific Shark's life history - and yes I'm still of the opinion that Whale Sharks come across as being particularly thick!
But one thing is clear, at least to me.
Despite of all those caveats, I too am convinced that far from being the ever lurking instinctive killing machines some quarters would have them be, Sharks are way smarter, and their life history and behavior, way more nuanced and sophisticated - and this paper is yet another step in revealing that fascinating and beautiful tapestry.
Thank you Tristan and thank you Doc!
No they do not!
They show that juvenile (= an adjective) Lemon Sharks (= a species) are able to learn a task by observing other juvenile Lemons and, as Doc tells me, that they could learn faster than rabbits or cats (= other species) on a conditioned response and could recall the response up to a year.
And what about the other Sharks? No idea!
Hell we don't even know whether those findings extend to adult Lemon Sharks, see the various hypotheses about slower and/or different learning that are being put forth for humans! Maybe Sharks, too, get more set in their ways and are less prone to experimenting as they grow up? I'm asking this as some of our old ladies do things in always the exact same way, likely because they have learned that it works!
My hunch is that if tested, different species will show different results.
And I'm also quite confident that there will be differences at an individual level - and possibly even at the level of gender or life stages, who knows!
I'm also expecting that the results will correlate with the extent to which those species are social (remember this is about social learning - which of course begs the question whether our Bulls are social!), but possibly, also with the extent to which learning is a useful strategy considering the specific Shark's life history - and yes I'm still of the opinion that Whale Sharks come across as being particularly thick!
But one thing is clear, at least to me.
Despite of all those caveats, I too am convinced that far from being the ever lurking instinctive killing machines some quarters would have them be, Sharks are way smarter, and their life history and behavior, way more nuanced and sophisticated - and this paper is yet another step in revealing that fascinating and beautiful tapestry.
Thank you Tristan and thank you Doc!
Thursday, May 05, 2011
Eric Clua on Shark Feeding!
Bull Shark traffic in the Arena at 30m - click for detail!Don't worry - no rant this time!
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!
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!
Tuesday, February 15, 2011
Jon - one helluva Birthday Cake!
Just got this from Jon McKenzie.
Hey Mike!
Hope all is well in Fiji! Thought I'd share a picture of the birthday cake my mom had made for me this year. She usually makes them and would have had more fun with the design but shes a thousand miles away so she outsourced it to Haydel's Bakery.
It was fantastic!!
So here's to Jon's birthday!
And to the excellent taste of his mum - and that of the cake!
John is one of the up- and coming lemon Shark guys.
His work on the Lemons in the Chandeleur Islands is extremely important. As far as I know, the islands are the only known nursery of this species apart from Doc's Bimini and some locations in Brazil, and may thus be the Lemon Shark hot spot for the whole of the Gulf of Mexico. Incidentally, having asked about the effects of the spill, I was very relieved to hear that everything there seemed to be OK and that the animals were plentiful and looked healthy.
Talking of Lemons, remember that paper?
Jon and Juerg have recently teamed up to write a critique, and the original authors have published a riposte - yes that would be a fencing term and it is exactly what has happened, not so much in the abstracts but in the full comments!
Very funny when done by researchers and thus wrapped in erudition and technical lingo!
More about it shortly!
Hey Mike!
Hope all is well in Fiji! Thought I'd share a picture of the birthday cake my mom had made for me this year. She usually makes them and would have had more fun with the design but shes a thousand miles away so she outsourced it to Haydel's Bakery.
It was fantastic!!
So here's to Jon's birthday!
And to the excellent taste of his mum - and that of the cake!
John is one of the up- and coming lemon Shark guys.
His work on the Lemons in the Chandeleur Islands is extremely important. As far as I know, the islands are the only known nursery of this species apart from Doc's Bimini and some locations in Brazil, and may thus be the Lemon Shark hot spot for the whole of the Gulf of Mexico. Incidentally, having asked about the effects of the spill, I was very relieved to hear that everything there seemed to be OK and that the animals were plentiful and looked healthy.
Talking of Lemons, remember that paper?
Jon and Juerg have recently teamed up to write a critique, and the original authors have published a riposte - yes that would be a fencing term and it is exactly what has happened, not so much in the abstracts but in the full comments!
Very funny when done by researchers and thus wrapped in erudition and technical lingo!
More about it shortly!
Thursday, September 23, 2010
About feeding Lemons in Moorea
Well well.
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 others arriving, 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 extenso here 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!
Case in point, this stellar interview with Aleks Makjkovic about her research with Caribbean Reefs in the Bahamas.
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 solution is 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.
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 others arriving, 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 extenso here 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!
Case in point, this stellar interview with Aleks Makjkovic about her research with Caribbean Reefs in the Bahamas.
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 solution is 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.
Friday, February 19, 2010
Lemon Shark Fishing Ban enacted!
Done!
May I really be the first blue blogger to report this?
I've been blogging about the efforts to have Florida's Lemon Sharks protected and it appears that this has just happened!
If so: wonderful news and big Kudos to everybody involved!
Walt and especially, Doc will be ecstatic!
PS thought so: Felix beat me to it!
May I really be the first blue blogger to report this?
I've been blogging about the efforts to have Florida's Lemon Sharks protected and it appears that this has just happened!
If so: wonderful news and big Kudos to everybody involved!
Walt and especially, Doc will be ecstatic!
PS thought so: Felix beat me to it!
Sunday, December 13, 2009
Florida - excellent News!
Hopefully, soon, no more of this in Florida!Bravo!
The good people from the Florida Fish and Wildlife Conservation Commission FCW have approved wide-ranging measures aimed at protecting the state's stressed Shark populations, among which a total ban on harvesting Silkies and Sandbars (and Atlantic Sharpnose Sharks which however don't occur in Florida waters).
And the commission has also approved (I hear, unanimously!) draft legislation to fully protect Florida's Lemon Sharks!
Great news and huge Kudos to the impressive coalition of activists, NGOs and scientists that have tirelessly worked towards achieving this goal. I read that a final public hearing on the proposed lemon shark rule will be held during the February FWC meeting in Apalachicola - so there, just one more push and it should hopefully be a done deal!
More info here.
The good people from the Florida Fish and Wildlife Conservation Commission FCW have approved wide-ranging measures aimed at protecting the state's stressed Shark populations, among which a total ban on harvesting Silkies and Sandbars (and Atlantic Sharpnose Sharks which however don't occur in Florida waters).
And the commission has also approved (I hear, unanimously!) draft legislation to fully protect Florida's Lemon Sharks!
Great news and huge Kudos to the impressive coalition of activists, NGOs and scientists that have tirelessly worked towards achieving this goal. I read that a final public hearing on the proposed lemon shark rule will be held during the February FWC meeting in Apalachicola - so there, just one more push and it should hopefully be a done deal!
More info here.
Saturday, December 05, 2009
Crunchtime!
Walt Stearns is a good guy (and brilliant photographer) and Doc is obviously a Shark God.
Both have put their weight behind trying to save the endangered Florida Lemon Sharks and for once, it looks like their lobbying and that of the good people over at the Shark Safe Network, and of many many others, are really having a positive effect.
So far so good.
But now, it's crunch time.
The Sun Sentinel has published this excellent overview of the current situation and if you're intrigued by the Lemon Shark aggregations it mentions, you can watch a short video of this amazing phenomenon right here, along with explanations by the Lemon Shark God himself here.
It is unique and also, highly vulnerable and needs to be preserved, as these may well be the breeding stocks of the entire Atlantic coast. They have also become a valuable resource for tourism, meaning that the Sharks are so much more valuable alive (as in 150,000 bucks per Shark over its lifetime) than dead.
Whichever way you choose to slice it, it is really imperative to see this through - and we are so close!
This is what's at stake.
The wildlife commission will decide whether to approve a draft ban (please read it, it amply explains why this needs to happen) on lemon shark catches at its Dec. 10 meeting in Clewiston.
The commission's ban would apply only to state waters, which extend three miles off the east coast and nine miles off the west coast. But the federal government, which regulates fishing up to 200 miles off the coast — except where that zone would run into the Bahamas — may follow Florida's lead if the state requests it. Karyl Brewster-Geisz, fishery management specialist for the National Marine Fisheries Service, said states normally request comparable regulations in federal waters for consistency.Being my usual pessimistic self, I fully expect the fishermen to make a last stand in an effort to ditch, or delay the legislation. The way I see it, this is not a done deal quite yet.
For them, it's obviously about their livelihood and their families and for some, it's probably also about their penis size, at least for sociopaths like that sharkman, or whatever, I've just blogged about (and yes I'm being polite!).
In brief, expect backlash.
Please please please take the time to attend that hearing and to lobby for the conservation of Lemon Sharks in Florida.
This is not about being anti-fishing, it is about being pro-Shark and everybody is invited to remain polite (yes, like me!) and fact based. The Shark Safe Network has done and continues to do an excellent job in coordinating the effort and you should contact them and refer to their judgment when it comes to formulating common arguments and pursuing a common strategy.
Also, if you haven't already done so, sign the petition as the decision makers do certainly care about the public's opinion.
Thank you.
Both have put their weight behind trying to save the endangered Florida Lemon Sharks and for once, it looks like their lobbying and that of the good people over at the Shark Safe Network, and of many many others, are really having a positive effect.
So far so good.
But now, it's crunch time.
The Sun Sentinel has published this excellent overview of the current situation and if you're intrigued by the Lemon Shark aggregations it mentions, you can watch a short video of this amazing phenomenon right here, along with explanations by the Lemon Shark God himself here.
It is unique and also, highly vulnerable and needs to be preserved, as these may well be the breeding stocks of the entire Atlantic coast. They have also become a valuable resource for tourism, meaning that the Sharks are so much more valuable alive (as in 150,000 bucks per Shark over its lifetime) than dead.
Whichever way you choose to slice it, it is really imperative to see this through - and we are so close!
This is what's at stake.
The wildlife commission will decide whether to approve a draft ban (please read it, it amply explains why this needs to happen) on lemon shark catches at its Dec. 10 meeting in Clewiston.
The commission's ban would apply only to state waters, which extend three miles off the east coast and nine miles off the west coast. But the federal government, which regulates fishing up to 200 miles off the coast — except where that zone would run into the Bahamas — may follow Florida's lead if the state requests it. Karyl Brewster-Geisz, fishery management specialist for the National Marine Fisheries Service, said states normally request comparable regulations in federal waters for consistency.Being my usual pessimistic self, I fully expect the fishermen to make a last stand in an effort to ditch, or delay the legislation. The way I see it, this is not a done deal quite yet.
For them, it's obviously about their livelihood and their families and for some, it's probably also about their penis size, at least for sociopaths like that sharkman, or whatever, I've just blogged about (and yes I'm being polite!).
In brief, expect backlash.
Please please please take the time to attend that hearing and to lobby for the conservation of Lemon Sharks in Florida.
This is not about being anti-fishing, it is about being pro-Shark and everybody is invited to remain polite (yes, like me!) and fact based. The Shark Safe Network has done and continues to do an excellent job in coordinating the effort and you should contact them and refer to their judgment when it comes to formulating common arguments and pursuing a common strategy.
Also, if you haven't already done so, sign the petition as the decision makers do certainly care about the public's opinion.
Thank you.
Monday, October 26, 2009
Florida - update on Lemon Sharks
Looks like the public workshop about the Lemon Sharks went well.
As does the petition!
That's what I gather from the messages I get and from the recaps on Oceanic Dreams and the Shark Safe Network blog. What I particularly approve of is that dialogue is being sought with the fishermen and that everybody is trying to find solutions that incorporate the needs of the fishing industry. No, I don't like it as it means that some Sharks will die - but, alas, it's the only way forward.
It's however not yet a done deal and surprises can always happen.
There will be another meeting and the all-important vote on December 10 in Clewiston and it is imperative that the pro-Shark advocates be once again represented in good numbers.
For now, congratulations to everybody involved!
As does the petition!
That's what I gather from the messages I get and from the recaps on Oceanic Dreams and the Shark Safe Network blog. What I particularly approve of is that dialogue is being sought with the fishermen and that everybody is trying to find solutions that incorporate the needs of the fishing industry. No, I don't like it as it means that some Sharks will die - but, alas, it's the only way forward.
It's however not yet a done deal and surprises can always happen.
There will be another meeting and the all-important vote on December 10 in Clewiston and it is imperative that the pro-Shark advocates be once again represented in good numbers.
For now, congratulations to everybody involved!
Sunday, October 11, 2009
Just another Petition?
A school of Silkies - great pic of an increasingly rare, and very lucky encounter by Ken Howard.I hate petitions.
Very often, all they manage to achieve is to embolden the opposition and to anger those that are being petitioned - but this one, I believe, is different.
Florida's Fish and Wildlife Conservation Commission (FWC) has proposed rules that would expand the list of protected Sharks to include the highly endangered Sandbars, Silkies (pictured above) and Caribbean Sharpnoses.
Whilst this is certainly laudable, it will apparently increase the fishing pressure on other big Sharks like Bulls, Tigers, Hammerheads and Lemons. The latter are especially vulnerable as they conveniently and predictable aggregate in a small area off Palm Beach, where they are the subject of research and a popular attraction for Shark lovers.
Thanks to incessant lobbying by "Mr. Lemon" Doc Gruber and a coalition of scientists, divers and conservation orgs, the FWC seems to be more than willing to add the Lemons, and maybe even other Sharks to the protected list. It really looks like they are good people willing to do the right thing.
The present petition is meant to lead up to the public workshops at the end of October where the protection of the Lemon Sharks will be discussed and hopefully, sanctioned as well. It will add credibility to the arguments of the pro-Shark advocates, as will a robust turnout by Florida's Shark lovers and marine conservationists.
Please take one minute and sign the petition.
Thank you.
Very often, all they manage to achieve is to embolden the opposition and to anger those that are being petitioned - but this one, I believe, is different.
Florida's Fish and Wildlife Conservation Commission (FWC) has proposed rules that would expand the list of protected Sharks to include the highly endangered Sandbars, Silkies (pictured above) and Caribbean Sharpnoses.
Whilst this is certainly laudable, it will apparently increase the fishing pressure on other big Sharks like Bulls, Tigers, Hammerheads and Lemons. The latter are especially vulnerable as they conveniently and predictable aggregate in a small area off Palm Beach, where they are the subject of research and a popular attraction for Shark lovers.
Thanks to incessant lobbying by "Mr. Lemon" Doc Gruber and a coalition of scientists, divers and conservation orgs, the FWC seems to be more than willing to add the Lemons, and maybe even other Sharks to the protected list. It really looks like they are good people willing to do the right thing.
The present petition is meant to lead up to the public workshops at the end of October where the protection of the Lemon Sharks will be discussed and hopefully, sanctioned as well. It will add credibility to the arguments of the pro-Shark advocates, as will a robust turnout by Florida's Shark lovers and marine conservationists.
Please take one minute and sign the petition.
Thank you.
Tuesday, September 08, 2009
Florida's Lemon Sharks in Trouble!
From the Shark Safe blog.
As regulations tighten for other fish, lemons sharks and other large coastal shark species - already in trouble! - are facing increased fishing pressure.
The Florida Fish and Wildlife Conservation Commission is seeking feedback from the public on options for amending its shark management rules.
Commercial fishermen are gearing up now to target the winter lemon shark aggregations off Florida's coast.
It's critical that as many people as possible speak up in support of greater protections for lemon sharks and other highly vulnerable large coastal shark species.
The Florida Fish and Wildlife Conservation Commission is seeking feedback from the public on options for amending its shark management rules.
Commercial fishermen are gearing up now to target the winter lemon shark aggregations off Florida's coast.
It's critical that as many people as possible speak up in support of greater protections for lemon sharks and other highly vulnerable large coastal shark species.
Please join Dr. Samuel Gruber, Walt Stearns, publisher of the Underwater Journal, and others who are concerned about the fate of Florida’s sharks in this effort to save lemon sharks and other highly vulnerable sharks.
Lemon sharks take 12 to 15 years to reach maturity and then only mate once every two years, have long gestation periods and give birth to a small number of young. These slow reproductive characteristics, very high first year mortality destruction of lemon shark nursery habitats, combine to make this species extremely vulnerable.
The lemon shark "aggregations" - large gatherings that take place off the coast of Florida in a small regional area close to shore with a highly predictable time frame, also make them easy targets for fishermen. Satellite tagging studies have proven that the lemon sharks that aggregate off Florida’s coastline have come from all up and down the East Coast of the US and the Bahamas.
Commercial targeting of Florida's lemon shark aggregations can severely deplete or even wipe out lemon sharks populations very quickly and will impact a large geographic area. This is a potential shark conservation disaster!
If at all possible, please attend this meeting and ask the FWC to add lemon sharks to the Prohibited Species List.
More important information here.
Lemon sharks take 12 to 15 years to reach maturity and then only mate once every two years, have long gestation periods and give birth to a small number of young. These slow reproductive characteristics, very high first year mortality destruction of lemon shark nursery habitats, combine to make this species extremely vulnerable.
The lemon shark "aggregations" - large gatherings that take place off the coast of Florida in a small regional area close to shore with a highly predictable time frame, also make them easy targets for fishermen. Satellite tagging studies have proven that the lemon sharks that aggregate off Florida’s coastline have come from all up and down the East Coast of the US and the Bahamas.
Commercial targeting of Florida's lemon shark aggregations can severely deplete or even wipe out lemon sharks populations very quickly and will impact a large geographic area. This is a potential shark conservation disaster!
If at all possible, please attend this meeting and ask the FWC to add lemon sharks to the Prohibited Species List.
More important information here.
The FWC Meeting will be held on September 10th 8:30 am. at:
10400 County Road 48
Howey-in-the-Hills, FL
Phone: (352) 324-3101
Fax: (352) 324-2636
Website: http://www.missioninnresort.com/
Contact Shark Safe Network:
sharksafenetwrk@gmail.com
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