Showing posts with label Blue Sharks. Show all posts
Showing posts with label Blue Sharks. Show all posts

Wednesday, September 30, 2015

Red Meat?


Watch.



Yeah that would be a Shark attack.
It happened because, and I cite,
"Sharks like to eat fatty red muscle...” David said.
Indeed - especially Whale Sharks and Angular Roughsharks!
I mean, seriously, that statement has the same truth content and educational value as if I professed that Mammals like to eat Eucalyptus leaves - meaning plus/minus zero! Like Cristina (brava!), it really bothers me that we put all ‘sharks’ into one pigeon hole and ascribe the same basic behaviours to them all, seldom realising that there are more than 400 species of different sizes, living in different environments and showing different behaviours!
And then, I read
So why do sharks bite?
Shiffman says it’s usually a case of mistaken identity. “Sharks aren’t used to things being in their environment that isn’t food. When a surfer cuts through the water on his board, wearing a white suit, he can easily be mistaken for a seal,” he says. But most of the time, once a shark gets a taste of his bony human dinner, he backs off in disgust. “The ‘hit and run’ is a common bite — they take one bite and realize it’s not what they wanted to eat,” Shiffman said.
Really.
Same old same old, and equally totally misleading - except that apparently, surfers now wear white garb! I can categorically assure you that the Blacktips and Spinners that strike surfers in Florida and the Bulls doing the same in Reunion Island are NOT mistaking them for seals!
Likely, the Floridian Sharks act in perceived self defense or are maybe caught up in a feeding frenzy (read this!); and equally likely, those Indian Ocean Bulls are engaging in predation - but of course we will never know for sure!
Bravo David for the laudable intention of wanting to put Shark strikes in perspective - but the stubborn ultracrepidarianism, and this from a self-proclaimed dragon-slaying myth-busting fact-based researcher is really irritating!

And that Blue Shark?
Judging from the head shake etc, methinks this is an attempt at predation - but again, who knows. But divers hovering next to bait bins whilst being obviously oblivious of the dangers and of their surroundings are a recipe for disaster. If this is a fun dive, then OK, shit happens - if, like it appears, this is a commercial dive with tourists, then those lousy protocols need to be changed, pronto!
Remember this shit? It gets triggered by stuff like that!

Anyway, just sayin!

PS: thread here - agree agree disagree who knows! :)

Tuesday, May 05, 2015

New Zealand - Bycatch Mitigation!


And talking of smart young people.
And I cite.
"So let's look at the real problems, which is this loophole of encouraging fishers to get back their hooks when they catch sharks... that loophole that allows them to bring it on board, kill it and throw it back and not count it."
Indeed!
The proposed legislation is certainly a step in the right direction - but mandating that Sharks be released alive but also collecting all the relevant data about that important incidental mortality would be even better!

Well said Riley!

Sunday, February 22, 2015

Shark Strike in the Azores - Debate!


Oh for crying out loud!

Have you seen this?
Spare yourselves the 40 bucks - in essence, the article recounts how a Blue Shark bit the fin of a pal of the authors, and this thusly.
An Unprovoked Attack by a Blue Shark Prionace glauca (Chondrichthyes: Carcharhinidae) on a Spear Fisherman in Terceira Island, Azores, Northeast Atlantic

On July 24, 2013, near a shallow water rocky reef approximately 50 m from the coastline, a 48-year-old spear fisherman was surprised by a blue shark that bit his right flipper. The incident occurred on the South coast of Terceira Island, Azores, Portugal, Northeast Atlantic, where a shark attack or conflict is a very rare phenomenon, having only 3 minor incidents previously recorded...

Late afternoon the spear fisherman entered the water and swam away from the adjacent fishing port, now converted into a leisure summer area, toward the tip of the adjacent rocky reef. 
There, he saw a school of Atlantic Bonito, Sarda sarda (Bloch, 1793) and immediately dove to place himself in a position suitable to target one of the fish swimming in front of him. As he descended to a depth of approximately 10 m, he felt his right foot being pushed and turned his head to see an approximately 2.1 m total length blue shark biting his flipper...

At the same time, he reported that at least 5 more similar-size blue sharks were close by, and he was able to chase the first specimen away simply by touching it with his left leg. The sharks disappeared, and the victim continued to fish in that same area with no further sightings.
And then the authors have the audacity to attribute the incident to Shark feeding as follows.
These offshore, mainly pelagic species do have coastal habits when in close proximity to oceanic islands, as happens to be the Azores. Moreover, they are attracted by tourist operators with feeding stimuli and may be already in the process of associating these stimuli with humans, namely, divers. Contrary to well-known coastal sites where this practice is common and local sharks seem to have residential habits while becoming conditioned by specific diving sites, Azorean targeted species roam vast areas and far away from the open water zones where they are mainly attracted.

In spite of the fact that some of the most dangerous species are seldom seen in the Azores, we believe that this practice of proximity and feeding stimuli to open water nonresident sharks is potentially dangerous and may well lead to more, possibly very serious, accidents in Azorean waters in the future.
In our opinion, close proximity of large predatory vertebrates to humans may well lead to accidents that sometimes may even be lethal. Apex predators, when accustomed to being enticed with food by humans, either for tourist purposes or from simple curiosity, are known to increase attacks.
Changes in shark behavior due to touristic activities such as “shark diving” were also documented by Hammerschlag et al.

We do think that care and common sense must surely prevail in these cases, while dealing with situations than can easily get out of control and lead to serious risks and overwhelming panic situations, which, if nothing else, will inevitably affect tourist activities as a whole.
Not so fast, says Juerg.
Here is his reply, unabridged.
Shark Attacks and Shark Diving 

To the Editor:
It is with great astonishment and concern that I read the letter to the editor by Barreiros et al in which the authors report an attack by a blue shark on a spear fisherman in the Azores.
Whereas the first part of the article accurately details the circumstances of the accident, Barreiros et al, in the second part,devise a far-fetched and illegitimate connection with shark div ing, in particular with shark feeding.

Shark-induced human injuries are among those inter actions between humans and wildlife that arguably receive the most media and public attention.
The general arguments of shark feeding critics are that 1) luring or feeding sharks over a period of time has the potential to condition them and that this conditioning could lead to sharks associating the presence of humans with food; and by insinuation, 2) make them aggressive toward humans. This in turn could lead to 3) an increase in accidents (eg bites)at shark feeding sites when no food is provided. Concern also exists that 4) regular shark feeding at ecotourism sites may increase the risk of shark attacks on ocean users in surrounding areas.

The first argument is beyond scientific controversy.
There is ample empiric evidence that elasmobranchs can be conditioned and are capable of learning to associate, for example, specific locations with food rewards. Recent studies looking at long-term trends in shark abundance at such sites have found numbers,at least of certain species, increasing over time,which further supports the quite unsurprising conclusion that sharks can learn to associate specific locations with food. It is this very capability shark diving operators capitalize on to set up profitable and sustainable businesses. No empiric evidence exists that would support the other 3arguments.

If shark feeding critics implicitly deduce them from the first argument,one has no other choice than to assume that what critics mean is not sharks “associating” humans with food, but “regarding” them as a food source. This could be viewed as semantics, but they are the very arguments on which authorities have based the implementation of legislation on shark feeding bans.
For example, in 2 highly publicized cases in 2002, Florida and Hawaii banned the practice of shark feeding while diving or snorkeling in their respective state waters.

Barreiros et al use a certainly tragic but single shark accident to fire an unsubstantiated broadside at the nascent shark diving industry in the Azores.
If shark feeding critics are serious about their assertion that sharks regard humans as food, then it is time to come up with fact sand figures. In doing so, the results of the respective studies will add to the objectification of the public discourse about feeding sharks as a tourism attraction. If shark feeding critics continue to refuse to address the respective questions by applying the scientific method, then their arguments remain what they currently are: tendentious and uninformed.

Juerg Brunnschweiler, PhD ETH Zurich, Zurich, Switzerland
And this is the riposte by the authors.
In Reply to Shark Attacks and Shark Diving

To the Editor:
 In his letter, Dr Juerg Brunnschweiler expresses both astonishment and concern regarding our paper when stating that it “devises a far-fetched and illegitimate connection with shark diving, in particular with shark feeding.”

We do not agree with Dr Brunnschweiler’s comments, because 1) our paper is not a “criticism” of either shark diving nor shark feeding but yet a description of an attack that might have had some kind of connection with the growing industry of shark diving in the Azores; 2) we clearly expressed a legitimate concern that, contrary to shark species with residential habits, the blue shark that caused this attack has pelagic habits and roams coastal areas of oceanic islands, and is the only species targeted by the Azores commercial shark diving companies; 3) the possibility—although rare—of interactions with humans and eventual attacks are real and may cause collateral damage to man upstream and downstream areas of maritime tourism in the Azores; and 4) panic and disproportionate fear, something that is worldwide associated with sharks, are critical issues and may lead to other types of accidents.

We understand and respect the diving operators’ will to capitalize on this specific niche of tourism. 
However, we think that it is our duty and even a responsible obligation to describe well documented events and discuss them within the scientific community. Throughout the world, many accidents presenting several degrees of gravity do occur. However, it is known that many remain unreported, either because they occur in remote areas or because there are many types of political pressures to avoid their knowledge precisely not to harm some types of touristic initiatives. That is one of the reasons why Dr Brunnschweiler’s comment when asking for “facts and figures” is so difficult to achieve.

And yet,in his last paragraph, DrBrunnschweiler expresses a very inelegant affirmation when he doubts our ability to use the “scientific method.”
We are certain that he knows perfectly well that we did use it, but numbers do not appear—and probably that will remain as it is for a long time simply because (and may we add, fortunately) shark attacks are rare.

Our arguments are precautionary and cautious.
Enticing predators and especially apex predators with food will lead to conflicts between humans and wildlife, and these happen all the time and in many places. This is not the first time that the description of an attack with a discussion on possible causes is criticized, and we thank Dr Brunnschweiler for doing precisely that. Discussing these aspects, however, may well lead to more caution and common sense when dealing with these types of animals. That will certainly improve human-wildlife relations, reduce conflicts, and certainly diminish high degrees of intolerance toward wildlife—and that will ultimately be of great help in protecting precisely these animals, including sharks.

In conclusion,we would like to add that, apparently, Dr Brunnschweiler expressed his legitimate concern for the industry of shark diving. We express our deep concern on behalf of the welfare of both humans and sharks.
Deep concern huh.
My take?
  • First, there is ONE scenario whereby the authors would be correct.
    That is, if some fool had been feeding Blue Sharks on that reef 50 meters away from the adjacent fishing port, now converted into a leisure summer area. I've said it before: location matters, and establishing a Shark feeding dive right in front of a tourist area would be utterly reckless and negligent, and the authors would be absolutely correct in asserting likely causality and being deeply concerned.
    But I don't think that's the case as every single picture of Blue Sharks from the Azores has been clearly taken in open ocean.
And if so, the assertion by the authors that they did use the scientific method is just plain ludicrous. Yes n=1 really does generally not allow for any deep insights, and Shark strikes are rare and thus elude science - and in fact, had they attributed the strike to the alignment of Mars and Jupiter, their finding would have had the exact same degree of veracity!
With that in mind, it would have been perfectly OK had they simply reported the incident - but once they started to speculate about the likely cause, then the scientific method would have mandated to examine all the possible scenarios and not simply jump to conclusions and blast what is obviously their pet hate, and this without a single shred of evidence.
So there.
  • Blue Sharks are big, bold and potentially dangerous.
    Yes they do not figure prominently in the Shark attack statistics - but that is both a figment of those statistics and also due to the fact that they are epipelagic and that there are usually not a lot of people perambulating in the open ocean. But as those gruesome shipwreck tales from WWII amply illustrate, large epipelagic Sharks will certainly investigate and eat people and thus, the surprise of the authors that a Blue Shark would approach, investigate and nip their pal is rather naive.

  • Incidentally, that's also not how a conditioned Shark would approach a person.
    As anybody that dives with fed Sharks can attest, they don't sneak in and then take a nip - that's typical of wild Sharks. Sharks that expect to be fed approach openly from the front and linger waiting for a handout.
  • But what were those half-dozen Sharks doing there in the first place?
    As the authors assert, the species is known to frequent coastal areas of oceanic islands so that's hardly surprising. In this case, it appears plausible that they may have been following their prey = those Atlantic Bonito, an equally epipelagic species that may in turn have been coming to the coast to feed.
  • Or maybe not.
    Maybe the cause for the presence of those Sharks was that the reef is frequently being used by spear fishermen. Or maybe it was the proximity to that fishing port. 
    Because let us never forget who feeds and conditions the Sharks: fishermen! 
    Spear fishermen produce fish blood and vibrations, attract Sharks and are frequently victims of Shark strikes. Fishermen feed Sharks with millions upon millions of baited hooks, clean their catch and discard bycatch, and specifically those Blues have been following fishing boats into port since time immemorial.  
    If there has to be talk of conditioning, that it is THAT the authors should have been focusing on, not a few people baiting with tiny scraps!
  • And what about the assertions that apex predators, when accustomed to being enticed with food by humans, either for tourist purposes or from simple curiosity, are known to increase attacks and that enticing predators and especially apex predators with food will lead to conflicts between humans and wildlife, and these happen all the time and in many places.

    Welcome to the fucking old tired "don't feed the Bear" argument!
    Yes "they" happen - but so far, when it comes to those big Sharks, that is simply not the case! Whereas accidental bites on feeders do happen, strikes let alone fatal ones on participating tourists are exceedingly rare, and any correlation (let alone causality) between Shark feeding and Shark strikes on the public at large is completely speculative and not at all supported by the evidence.


    In fact, and yes I'm repeating myself, people who feed large Sharks are acutely aware that it is dangerous and are exerting tremendous caution and common sense - and as a consequence, the danger of those activities is significantly smaller than interactions with other marine life (including smaller Sharks) that are being viewed as more harmless; and it is orders of magnitude safer than "normal" diving! 

  • In fact, if anybody had to be reprimanded, then it would have been the victim, for being totally reckless: for potentially attracting Sharks to a tourist area, for spearfishing at dusk when predators are known to feed and above all, for not immediately leaving the water but instead continuing to spear fish after having been nipped!

  • And finally.
    That will certainly improve human-wildlife relations, reduce conflicts, and certainly diminish high degrees of intolerance toward wildlife—and that will ultimately be of great help in protecting precisely these animals, including sharks.


    What a load of sanctimonious horse shit!
    Fishermen target Sharks for money - not because they hate them for biting people! That argument is frankly so stupid to be embarrassing!
    Want to save those Blues? Take a boat to Vigo and tell those fishermen to stop targeting the Azorean Blue Shark nurseries - or at least stop wasting people's time and patience with BS, and work on making a stock assessment and on implementing a management plan for sustainable Blue Shark fishing in the Azores!
    That's how real scientists contribute to Shark conservation!

  • And one very last remark: how the fuck did this manage to get a pass by the peer review?
Long story short?
It's exactly like Juerg states: this is not science but total bullshit, nothing more than a completely unsubstantiated broadside against the nascent Shark feeding industry in the Azores, and this clearly not based on the evidence but driven by one's uninformed prejudices.

And yes I can leave it at that.
Not impressed and once again, rather pissed off!

Saturday, November 03, 2012

New Study: Shark Finning in the Pacific!

Source.

And I cite.

A new study reveals worrying declines in Pacific shark populations, due mostly to the shark fin trade.
The results:
  • Pacific population of the oceanic whitetip shark declined by 17 percent between 1995 and 2010
  • The north Pacific blue shark decreased by about five percent per year in the same period
  • There was a decline in shark size over the 15 year study period, a clear indication of overfishing
These findings suggest that bans on shark finning are not helping nearly enough to protect sharks.  Their failure is most likely due to lack of enforcement and the increasing market for shark meat.
“These findings underscore conservationists’ messages that most finning bans are not properly enforced, and alone are insufficient to reverse shark population declines,” explained Sonja Fordham, President of Shark Advocates International.

Also, read this and listen to this.

Bingo.
Please do re-read this post.
We got to stop advocating only finning bans because that is not the solution: most countries have them anyway - but enforcement sucks and even if the bans are being followed, by now the fins are so valuable that landing the whole animals is profitable, meaning that those bans don't reduce the number of Sharks that are being killed, at least not adequately.
I'm also not in favor of fins-attached policies and even less, of fin-to-body ratios and the like as the associated bureaucracy and thus cost is staggering and because they present huge loopholes.

What we got to advocate is sustainability.
Ultimately, this means drastically reduced quotas and there, we got to ask the fishermen to prove that whatwever quotas they want to fish are fully sustainable - and until they do, they should not be allowed to retain and land any Shark let alone only its fins! 
Incidentally, at least when it comes to this specific region, the OWTs are protected as of next January - but then again, let's keep an eye on the implementation!

Saturday, March 31, 2012

California Blues!


Great Video!

This film is a tribute to those times when everything comes together to make a magical moment.
I shot this film on one perfect, cloudless, windless afternoon with clean water off Anacapa Island and at least six blue sharks under our boat. The largest was 8 feet long and the others were between 5-7 feet.

Shark populations have declined worldwide, including blue sharks, and seeing this many blue sharks at once was like a dream come true. I remember frequently seeing blue sharks swimming on the surface of the water during the late 80s while crossing the channel to the northern California Channel Islands. Nowadays, you are not likely to see any.

Indeed, what a serendipitous moment, beautifully captured!
Enjoy!



Thursday, November 24, 2011

Only Bycatch?

Blue Sharks in pre-tsunami Kessenuma, pic by Shawn Heinrichs - click for detail.

And talking about the WCPFC.
The following Shark bycatch figures have been reported for five Spanish surface longline vessels operating in the region in 2010.
  • Blue shark = 717 mt
  • Shortfin mako = 218 mt
  • Oceanic whitetip shark = 0.5 mt
  • Sandbar shark = 0.1 mt
  • TOTAL = 935.6 mt
And then, there is the following Note: The EU-Spanish surface longline fleet has never carried out finning practice in Pacific Ocean.

Yes you've read it correctly: that would be five vessels!
Here are the total Blue Shark figures for other countries.
Australia 13.90 mt; China 506.00 mt; Japan 7,624.00 mt; Korea 1.44 mt; New Zealand 712.00 mt; Samoa 0.19 mt; US 7.00 mt.

Sound plausible to you?
May the Spaniards still be at it?
Having emptied their own waters, may they have come here under the umbrella of the European Union in order to target those Sharks whilst pretending to be fishing for Tuna? Remember that those "bycatch" figures mean that those Sharks were retained, i.e. killed!
Does that hypocritical Note still make you happy?

This is what the Shark Alliance writes.

Over the last decade, European participation in the Hong Kong fin market, led by Spain, has grown from negligible levels to nearly a third of total declared imports.
This share is likely to be an underestimate as fins taken by the Europe’s distant water fleets may be credited to other countries.

The fact is that those Sharks could have been easily released.
Blue Sharks are particularly hardy and here is what this document by Pew teaches us.

According to the IUCN, bycatch is one of the most devastating threats facing sharks.
Although some RFMOs have prohibited the taking of a small number of threatened species, the problem of shark bycatch has been largely ignored, and no meaningful or effective action has been taken to adequately address the issue.
In the late 1980s and early 1990s, it was estimated that 300,000 metric tons (t) of shark catch, nearly a third of the global total, were the result of unregulated bycatch landings. Sharks are caught in different fisheries such as trawls and gill nets, but pelagic longline fishing is considered the most significant source of the bycatch problem.

Longline vessels that fish with wire leaders or use squid for bait in a shallow-set manner have the highest levels of shark bycatch. In pelagic longline fisheries, sharks often make up more than a quarter of the total catch (target and bycatch).

More than 70 percent of blue sharks survive after being hooked on a longline and brought onboard, and an additional 80 to 95 percent of the discarded blue sharks are expected to survive the release process.
In the U.S. Atlantic, pelagic longline fishery survival rates are even higher, with 97 percent of tiger sharks (Galeocerdo cuvier) and 87.8 percent of blue sharks surviving the fishing process.

And then, there's Chinese Taipei, i.e. Taiwan.
Their small- and large scale Tuna long liners have caught a whopping 10,989 metric tons of Blue Shark in the region - notabene as bycatch!
And take a wild guess as to where that "bycatch" is being offloaded!

And what about Fiji?
Take a look for yourself and draw the inevitable conclusions!

Sunday, September 11, 2011

Good Post!

Blue Shark, apparently still regularly sighted around the Azores. Pic Justin Hart.

From this piece by tharu1.
The (California) ban is still good legislation because it removes the incentive to kill sharks in pelagic longline fisheries. These species do not face biological extinction, but sustainable population numbers are important to maintain the ecological balance of the pelagic realm.

Case in point, the quasi extinct Blues off California.
As Scott Cassell opinionates, the disappearance of those Sharks may well be one of the causes of the recent upsurge in Humboldt Squid. Dunno if anybody is looking into this scientifically but the correlation is certainly plausible. Read this for correlations to the El Niño and its effects on the North Pacific Hake fishery.
Time for some giant calamari - recipe here!

Oldie but goodie here!



Anyway, nice to see a voice of reason away from the usual hyperbole!

Friday, May 21, 2010

Oceanic Sharks - shifting Baselines!

I was very impressed by Lupo's latest portfolio.

Great pics and I particularly liked this.
Of course when diving with sharks you always treat the shark with respect. You keep an eye on them and enjoy their beauty - Neither side were prey or predator, competitor or enemy. Both sides were curious and we were obviously more excited about seeing them than they were seeing us.
Well said my friend!

On a personal note, that portfolio is also pretty scary!
Thing is, I did like the Oceanic Whitetips - but what really got me excited was this pic of a Blue!


How sad is that!
It seems like yesterday when Blues were everywhere and such pics, hopelessly commonplace.
There was a thriving Shark viewing business operating out of San Diego and the Blues were merely the garnishing for the coveted Shortfin Makos and many other oceanic denizens like Billfishes, Basking Sharks, Mola Molas and big schools of Yellowfin.
All gone now, the Sharks and as a consequence, the businesses - and this in the USA, not some impoverished third world country lacking the resources to implement meaningful conservation measures!

Oh well.
Once again, and like in the case of the European Eel, I'm being confronted with my very own personal amnesia. It's a case of shifting baselines and a reflection of the big picture whereby all fisheries are severely depleted, to the point where some argue that most will collapse by the middle of this century.
Solutions? Read this and explore the link! Hat Tip: Mark!

But I'm digressing as always.
Lupo: well done!