Tiger Sharks in the Galapagos - Paper!

Cool!

Check this out.

I must say that having gone there several times and never having heard anybody mentioning them, I was totally surprised when reading about the occurrence of Tiger Sharks in the archipelago - but then again, considering the numerous (possibly distinct) Green Turtles and their nesting beaches, it makes total sense! 

May this be a rather recent phenomenon like in Cocos where there however were previous reported sightings by Hans Hass and Zane Grey? Considering the tracks, quite possibly - but then again, who knows!

The findings?

Much in line with what has been reported by Adam and Richard in Raine Island = that most Tigers would remain in the vicinity of the Turtle nesting site but that some would roam further. The way I read this, this once again confirms that those Tiger Shark migrations remain highly complicated and mediated by environmental factors - which of course begs the question, what is the influence of the ENSO = there is definitely a need for longer term monitoring studies.

Anyway, very interesting indeed!

Enjoy the paper!

PS - turns out that I've really not been paying attention!
 

Tagging Sharks - Article by Neil!

Source.

And I cite.

That said, at times it is necessary to keep some information “privy” (i.e., shared only with regulators) such as the location of a specific unknown aggregation site but such instances are uncommon.

Bingo.

Remember this, and the debate?

To my knowledge, this is the first time that a researcher has publicly addressed my only reservation against satellite telemetry in general and publishing those tracks in particular, i.e. that like in the case of those Fish spawning aggregations, publishing the location of particular hot spots may be unwise.

I say, bravo Neil.

His article in Nat Geo convincingly and comprehensively refutes the various allegations spouted by the loony fringe against especially those SPOT tags. Yes the process is by no means perfect - but in weighing the pros against the cons, it is crystal clear that the advantages prevail. Plus, this is obviously an evolution where all researchers continue to refine their methods to make them as little invasive as possible.

Required reading!

And here's a plug for the RJD Shark tagging program 

Enjoy!

Philopatry - Debate!

Source.

Remember?

Now, David has picked up the topic over there at SFS.

I understand and condivide his frustration with some of the anti-tagging fanatics, of which Dr. Schmidt's frothy circular echo chamber remains the most egregious example - but of course that's not the whole story.

Opinions?

Post them there, not here!

Big GWS off the US East Coast!

Source.

And talking of increasing GWS populations.

Check out the video.

That's a big = old Shark - which of course leads to the question, where were those big mamas hiding all those past years!

Enjoy!

Guadalupe Great Whites - Paper!

Location data for the four satellite-linked radio-telemetry-tagged female white sharks during the pupping phase.

Epic!

Read the paper!

No I'm not going to write a synopsis as it is open access, short, incredibly interesting and informative, and crystal clear insofar as it does not contain any obscure scientific lingo - and anybody ever wanting to talk about Great Whites needs to have read it!
Yes, female GWS follow a two-year breeding and migration cycle, something no PAT tag has ever been able to document!

And, there is this.

Jorgensen et al. have proposed an alternative life-history hypothesis that is contradictory to the hypothesis proposed by Domeier. The major difference between these hypotheses pertains to the timing and location of mating. Jorgensen et al. speculated that white sharks are mating during their offshore phase, whereas Domeier proposed that mating occurs during seasonal, near-shore, adult aggregations...

The offshore-mating hypothesis is based upon the conjecture that a described vertical-diving pattern (rapid oscillatory diving (ROD)) is a result of a lek-like mating behavior in the core of the SOFA. This interpretation is problematic from several perspectives. Lek-like mating systems involve the gathering of males at a traditional site for the purpose of ritualized courtship display. The males compete for the attention of females, and in turn, the females select a specific male for mating. Although the peak in ROD behavior, and thus presumed offshore mating, occurs during June/July in a period when the distribution of males temporarily constricts, even the constricted offshore space is vast (estimated to be about 64,000 km²). Lek-like mating would require the males to be in a very small space to allow females to observe the courtship of several males at once. No electronic-tag data have ever indicated that sharks are densely populating a small, traditional offshore site. Lek-like mating systems have been described for some species of fish, but leks have never been seen among elasmobranchs. Females that mate in lek systems select a single male deemed superior to other males, thus the fact that white-shark pups from a single litter tested positive for multiple paternity argues against lek-like mating for this species. 

It is challenging to ascribe any behavior to vertical movement data in the absence of visual observations. The seasonal constriction of the SOFA and the ROD-type diving pattern could be due to the pursuit of a seasonally available prey. An expedition to this region during the constriction identified the presence of three species of spawning squid and sperm whales, but again, the absence of behavioral observations deems it impractical to assign any cause to the ROD diving pattern. Diving patterns and mating systems aside, there are other strong arguments against the hypothesis that white sharks are mating during the offshore phase of their migratory pattern. First, electronic-tag data indicate that males and females are largely segregated during the offshore period, and second, the proposed mating during June/July would equate to December/January pupping (accepting the 18-month gestation estimate). Females arrive at adult aggregation sites approximately in September, and depart in December to end of February. No YOY have been seen at the adult aggregation sites, no obviously pregnant females have been sighted at GI, and pupping is known to occur approximately April through July.

Bingo!

I really had to laugh out loud - remember?

Basically exactly what i said - which begs the question, does the man read my posts? What I did not know was the fact about multiple paternity - the exact opposite of what would be expected in lek mating!

Eat that, Sal!

Anyway.

Bravo Michael Domeier and Nicole Nasby-Lucas - this is truly seminal stuff. And, thank you for the chapter about conservation concerns! 

And I repeat: read it!

And now, watch this.

Right.

Looks like the bunch of dipshits with an opinion and a keyboard has spawned a dipshit with an opinion and a camera who is now publicly spouting the usual moronic rubbish all the way to having the audacity to post that picture of Junior! 

All so pathetically SvS.

But fear not, I'm not gonna dwell on the latter. 

As per Patric's update and after now many weeks of him having produced zero, zilch, nana da nada evidence for his assertions, I'm done with the man and his verbose excretions!

Anyway.

Does that mean that I now endorse SPOT tags?

It depends!

Research does not consist in slapping on some tags in order to then look at what happens - the scientific method demands that one formulate a (plausible - see the lekking fiasco!) hypothesis and then test it, for which one needs to employ the adequate tools.

So IF the hypothesis requires gathering multi-year data about a species that conducts large migrations and IF the animal comes to the surface frequently which is necessary for up-linking to the satellite, and IF the questions being asked are important, then I absolutely support deploying SPOT tags!

As I said here, research about philopatry is vitally important for conservation purposes!

Example?

The GWS that aggregate and regale the cage divers at the Neptunes are likely to be among the very same animals that munch on unsuspecting aquatic recreationists in Western Australia, quite possibly in tandem with GWS that travel there from SA.

Both hypotheses have already been validated by PAT tagging tracks, and possibly even via acoustic tagging - but we still don't have the full picture insofar as we don't know where they mate, where they pup (or do we?) and why, exactly, they and some of the SA GWS travel to WA.

That is simply vital information if we ever want to understand and then address and manage the mess in WA and protect those Sharks - and of course the people!

And how would one go about in gathering that info?

Assuming (which is not a given!) that the females of that Australian population follow the same 2-year cycle as those from Guadalupe, then SPOT tags would be the ideal tool, vastly superior to PAT tags that do not have that longevity! The ideal tagging location would be the Neptunes where the Sharks aggregate, and the operators there should really consider inviting a knowledgeable GWS researcher - out of intellectual curiosity but also very much in order to safeguard their assets!

But not Fischer's wandering circus!

I dislike the man but that's obviously not the issue.

The issue is that by today's standards, his methods are unnecessarily invasive. Domeier has proven that very large GWS can be caught and then tagged whist submerged; and he has also developed a cradle for the tags whereby there is only one single attachment bolt, thus greatly reducing the risk of fin damage. 

Is that perfect?

Certainly not - but it's a great improvement and in view of the importance of finally gathering the necessary information about that population, I for one could personally live with some possibly warped or shredded fins. But I would not publish any tracks - at least not at this time of public pressure and according political brinkmanship in WA. Imagine the fiasco of showcasing the Sharks' real-time location, only to have one executed by some overly zealous government bureaucrat - highly unlikely but why take that risk!

But I'm digressing as always.

All I really wanted to say is, epic and congrats!

Read the paper!

Fischer on CNN!

I still don't like the guy.

But the science is brilliant.

With plenty of caveats mind you!

And the picture above, i.e. a deformed and possibly shredded tip of the fin that does not impinge on the animal's chances of survival? Fodder for the usual frothy Sharktivist rants - but from a conservation POV, it is really pretty much irrelevant!

Shark tagging - Progress!

I was happy to read this, and I cite.

MCSI's Dr. MICHAEL DOMEIER AND DR. OSCAR SOSA-NISHIZAKI (Director of CICESE) PERFORM THE WORLD'S FIRST IN-WATER SPOT TAGGING OF AN ADULT WHITE SHARK.

New methods developed, tested and implemented by MCSI involve a device to prevent gut hooking, soft fishing gear to prevent skin abrasions and constant forward movement to fully irrigate the gills.

Sharks tagged in this manner, including the largest white shark to ever be SPOT tagged, were far more vigorous upon release than our previous method that lifted the sharks from the water. We strive to constantly improve our methods to do what is best for the sharks and the scientific community. We have many to thank, but those who deserve special mention include veterinarian Dr. Erik Madison, Mr. Keith Poe and Davidson Boats.

Stay tuned for updates...and apologies for the long FB absence during our expedition.

Cool!

I ignore the details but will just blindly speculate that this is happening somewhere in Baja and aimed at unraveling the mysteries of what those adult GWS females may be doing there - and incidentally, whatever happened to the van Sommeran tag saga? Dead and forgotten, and buried under a mound of evasive verbal diarrhea? Much like the larmoyant and equally totally pulled-from-the-arse fable of Spots?

But I'm digressing as always - sorry!

The fact is that it appears that Shark tagging is advancing in leaps and bounds, and this in the right direction! I was already quite impressed by the better protocols and hardware adopted by the OCEARCH team - and this, i.e. keeping the Shark submerged clearly eliminates one of my biggest grievances. And there might be more: having been alerted to this page and noticed the name of the developer, may we be witnessing the deployment of SPOT tags (click on Finmount) via one single bolt = much less invasive and much more likely to fall off cleanly? Dunno - but sure hope that's the case!
And there's also a preventer against gut hooking!

And my harebrained suggestion that receivers may follow the tags?

Maybe not so harebrained after all - and here!

Leaves the question about the risk of publicly posting those tracks.

A prominent researcher who very graciously decided to address my concerns writes

Fishers already know where and when to find the fish they want to catch, commercial fishers wouldn’t make a living and sport fishers would take up golf if they didn’t.

The reality is that the scientific community and fisheries managers are constantly playing catch-up when it comes to knowledge about exploited species and their overlap with fisheries. It is the fishers that spend the most time on the water and generally have the most intimate knowledge of the behaviour of the fish in their patch. If this information is ever voluntarily shared with management agencies or fishery scientists its generally only in retirement.

 The beauty of satellite tags is that they allow us to connect the dots, those scraps of information contained in CPUE data, biological samples and conventional tag returns, and making this information widely available in a way that engages a broad cross section of society certainly appears to generate a much deeper appreciation of the animals and how strongly biologically connected even distant seascapes are.

Absolutely true - and yet I remain concerned! 

I totally subscribe to the notion that the research about philopatry is vital. But by publishing the tracks, especially when they reveal the oceanic highways and hotspots of a whole population like e.g. here on the TOPP pages that display location and time frame - aren't we inviting the fishermen to also concentrate their efforts in those locations and at those times?

Probably it's species- and situation-specific. 

E.g. I'm not really concerned about those GWS tracks as those Sharks are simply too few to warrant a specific targeted fishery, especially considering the distances and vast territories that would need to be covered - but those Salmon Sharks and Makos may be another matter altogether, the more as they appear to be much more coastal! Like in the case of Fish spawning aggregations where we've learned to keep the locations secret, maybe the risk/reward analysis of outreach vs fishing is too much skewed towards the risk of further depleting already highly fragile populations.

Just saying - opinions?

Carol - gallivanting around in the SoPac!

Carol with SPOT tag.

Behold Carol the Mako Shark!

Kudos to Clinton Duffy, he of Grim the GW!

He and colleagues have tagged Carol in May and like Grim, she has left New Zealand and gone walkabout all the way to western Fiji.

Story here.

And here is the interactive track on Guy and Mahomood's research website - which of course raises the same fundamental questions about the pros and cons of posting this kind of information online!

Opinions?

Taggings GW Sharks in New Zealand!

This is record deep diver Shack

Remember Grim the Kiwi tourist?

Now there's more data from his pals.

The NIWA researchers have tagged an additional 23 Great Whites this April and the first results have just come in. confirming that the animals will travel as far as Oz, New Caledonia and Tonga.

And Fiji - fingers crossed that we get lucky, the correct time frame is right now!

Here's a nice video explaining the research.

Enjoy!

Deciphering Philopatry - good or bad Science?

Great HH with one of Neil's new tags.

Want to go and catch yourself some Salmon Sharks?
Nothing could be easier: go fishing in the Northern Gulf of Alaska in November - and bingo! And if you believe that the fishermen have not long discovered the TOPP tracks - think again!

As Juerg writes in his correspondence to Nature.

Two faces of marine ecology research

The ecology of animal movement is one field that would benefit from sound evaluation of the risks, benefits and ethics of its important research findings (Nature 484, 415 and Nature 484, 432–434; 2012 read it!).

Scientists can now track the complex horizontal and vertical movements of a wide range of marine species, including tuna, sharks and turtles. These results reveal biodiversity hotspots and inform conservation policies by providing insight into animal behaviour and ecology. However, they also guide fishing operations towards resource-rich locations — putting further strain on both target and by-catch species.

Too many species face severe stock depletion because of intense fishing, pollution and other anthropogenic pressures. The detrimental implications of marine ecological research results must be acknowledged.

Juerg Brunnschweiler
Swiss Federal Institute of Technology (ETH Zurich), Zurich, Switzerland.
But there is of course also this.

It is possible, by marrying electronic tag data with oceanography, to gain a sufficient understanding of ecosystem function to enable more effective management of ocean resources.
Specifically, this study shows that when bluefin tuna enter the Gulf of Mexico, they are going to specific locations, where cool, productive water in “cyclonic eddies” makes its way along the continental slope. So during April and May, when they are spawning, bluefin tuna are relatively concentrated – whereas yellowfin tuna remain disbursed broadly throughout the Gulf.

This suggests that it would be possible to protect the bluefin, which are accidentally caught on longlines intended for yellowfin, by restricting fishing in those specific areas where the bluefin are spawning; but that such restrictions need not reduce yellowfin catch rates since they are more uniformly distributed.

Or this.

Great white sharks are found in waters all around New Zealand. National Institute of Water and Atmospheric Research (NIWA), and Department of Conservation (DOC) scientists are investigating the long distance movements of great white sharks inside and outside New Zealand’s territorial waters to improve our understanding of their species’s migratory patterns.
It will assist with designing management measures to reduce shark bycatch in fisheries.

Niwa principal scientist Malcolm Francis said despite the process sounding rough, the safety of the sharks was at the heart of the project.
As part of a wider study which began in 2005, it is hoped the research would return population figures and migratory behaviour of the protected species to assess how many sharks were being killed in fishing nets and lines.

Yes it looks like we got ourselves an ethical debate!
But maybe not so much - and whilst you're pondering, here's a rather epic video about that GW tagging in New Zealand.
Enjoy!



So what about those tracks.
As Bob Hueter already stated in 1998,

I consider the issue of philopatry and natal homing in sharks to be the most important issue in shark biology today, and I challenge all shark researchers to test this hypothesis rigorously in their respective research areas.

Nearly every type of shark research can play a role in this, for the ramifications of philopatry, if true for most shark species, would be profound. It certainly would affect our views of shark evolution and genetics, and it would shape new perspectives on the physiology and ecology of shark species. It would fundamentally affect studies of shark population dynamics, and perhaps most importantly, it would drastically change conventional views of shark fisheries science for the management and conservation of shark populations.

Hundreds of thousands of dollars and thousands of tags later, we now know this.
Sharks and Fishes are not randomly distributed throughout the oceans. Instead, they frequent well determined seasonal, behavior-, gender- and age-related hotspots and travel between these focal points on well determined marine highways.
Or as Hueter and Heupel write in 2004 (read it, this is seminal stuff!)

Many shark species are highly migratory, some covering thousands of miles of ocean in a single year.
However, with the emerging evidence of philopatry in various shark species, it would be wise from a conservation and management perspective to not view this group of marine fishes as oceanic nomads, but rather as more sophisticated, long-distance travelers with a number of discrete homes in the sea. How precise those homes are will need to be established with further research and analysis.

For us Shark conservationists, those data about philopatry are absolutely vital.
As I've tried to show here, many Sharks continue to fall victim to incidental catches despite of being protected, something that can be countered by establishing seasonal localized fishing bans; and like in the case of Playa or, say Vietnam, those localized and seasonal measures may be easier to achieve than trying to enact blanket protection of a species year-round and country wide.

This I believe is also the next step after having established those Shark sanctuaries.
With the big announcement hopefully looming, we're consequently already mulling the next big project that is hopefully going to lead to the full protection of the Shark nurseries, and thus of the valuable big pregnant females during the birthing period.
Keep watching this space!

But what about those published tracks?
Are those publications, maps, interactive websites and apps not simply showing the way for anybody wanting to go and kill the animals? And there is of course also the Anthropogenic Allele Effect, specifically the possible impact of poorly regulated tourism on the animals once newly discovered hotspots are being publicized - like e.g. here!
Like Juerg appears to assert, I fear that this is very much the risk!

Solutions?
Like I said, maybe it's not that difficult.

• Research and data per se are neither bad nor good; and if the track record is any indication, nobody is going to ever be able to stop scientific progress whatever the associated risks. That's just how things roll in science.


• But the risks are real - re-read the examples in Nature.


• Hence the inevitable conclusion, that whoever conducts the research cannot just disassociate himself from the possible consequences. Instead, it behooves the researchers to be fully accountable for their actions, and to be instrumental in mitigating the potentially negative implications of their queries. Obviously, this is easier said then done - but shying away from one's ultimate responsibility won't do, either!

But to come back to the topic of this post.
The data derived from telemetry studies (nice synopsis here!) are vital - but posting those tracks can only happen, if at all, with the utmost of circumspection.
It's exactly like in the case of Fish spawning aggregations where the ichthyologists have learned the hard way that it is better not to publish the exact locations: I say, unless there is unequivocal, robust and above all, fully enforced local management and/or protection, those data should be withheld and only shared with the relevant authorities and like-minded researchers, and this only in the aim of enacting adequate conservation and management measures.
And even once those measures have been enacted, it should be amply sufficient to publish large scale maps and keep the fine scale and exact GPS coordinates a secret.

Or am I missing something here?