Sunday, April 13, 2014

Hooking Great Hammerheads?

Is this cool? Source.

Watch this.

David disapproves.
This is an old and extremely thorny debate.
GHH are protected in Florida, but catch-and-release is perfectly legal - but ever since the publication of Austin's paper, we know that the post-release mortality rate is unacceptably high, meaning that anglers should actively endeavor to avoid hooking that particular species which is obviously easier said than done.
This is also the gist of this article in the Huff Post featuring quotes by both Austin and Neil, and where Kim Holland doubles up by asserting that in many cases, we know that even a moderate amount of handling will result in death even if you don't actually see it happen immediately in front of you.

So far so good.
So what about this - posted by the very same people who have published that paper and are lecturing the recreational anglers?

To say it mildly, this is a tricky one.
Do those mortality rates also apply to GHH that are being hooked by researchers - and if so, can David's passionate defense of research really be regarded as a sufficiently convincing blanket justification for angling for this unusually fragile, protected species?
Yes of course research into philopatry is extremely important (and in some aspects, controversial) - but in this specific case, there exist other, way less invasive protocols (and here) that may well yield very similar data!
With that in mind, would it not be appropriate to sacrifice some of the higher resolution and longer battery life of SPOT tags in favor of e.g. PATs that can be set on the fly either underwater of from the boat after the GHH has been teased to the surface?

Tricky tricky - thoughts?

Comments policy.
Read this. Not everybody's opinion is equivalent, and I shall only post cogent arguments about this specific matter, not attempts at engaging in the usual frothy tirades against researchers in general and/or OCEARCH in particular, etc.
My blog my rules!


Shark Diver said...

I think the pertinent question is this. How important is the data that can only be obtained with spot tags?
Is the data worth the risk of killing the sharks to get it?

I don't know the answer, but hopefully the researchers do.

Whysharksmatter said...

Hi, Mike!

After we discovered the sensitivity of hammerheads to fishing (long before we published our study), we modified our protocols to reduce handling time for hammerheads. They are only boat side for as long as it takes to cut the line and attach a quick-deploying tag.

Other sharks that are less sensitive receive a full research work up, including taking a variety of measurements and samples. From the time we observe a hammerhead on the line to the time it swims away released averages less than ten minutes, including the time spent reeling it in.

I'm happy to answer anyone's questions.

DaShark said...

Less than 10 minutes - that's impressive!

Do you have any guesstimates about the extent by which you are able to reduce the post release mortality?

Whysharksmatter said...

We have that data somewhere. I don't know it offhand but I'll ask.

jsd said...

I remember a commercial/sports shark fisherman in Florida telling me 30 years ago that a hooked hammerhead is a dead hammerhead -- so this is hardly news.

We indeed need to know the mortality of these tagged-and-released hammerheads.

DaShark said...

Over to you David!

You can obviously discern where this is going.
The question is, compared to less invasive alternatives, are the data from those specific tags so unique and important that they warrant killing some of those Sharks?

Thorny thorny!

Neil Hammerschlag said...

I appreciate your concern. However, the comparison made between our conservation research and hammerhead sport fishing is inappropriate. Fishing for sport is fundamentally different than sampling sharks for research. To in anyway infer that we are hypocritical is unfair and disappointing.

My lab has been studying the stress physiology of hammerheads for several years and we are in a good position to understand how our research could impact these animals.

Below is a brief summary of methods that we use to promote hammerhead survivorship during our research which we have implemented based on what we have learned through our work:

- We capture sharks using rotating-circle-hook drumlins that allow the sharks to swim in large circles and ram ventilate on the line promoting vitality (versus fight with impaired movement against some other fishing gears)
- We have short gear soak times of just 1 hour, although longer would be optimal for catching more sharks. We intentially have implemented short soak times, specifically, so we can get to the hammerhead sharks quickly since other sharks can tolerate being on the lines much longer.
- We use hook timers that indicate how long the sharks have been on the line – this allows us to help judge their stress levels and decide whether they are worthy candidates for further sampling and tagging versus immediately releasing.
- We routinely release hammerheads that have been on the line for long periods and if showing signs of significant fatigue
- When we do make the decision to sample and tag a hammerhead upon capture, we use a different protocol than we use on other sharks to ensure rapid release despite obtaining less data. This includes keeping the sharks in the water if conditions permit, not taking a biopsy, not drawing blood (unless it can be done simultaneously as tagging), estimating length (versus taking 15 morphological measurements as we do on other sharks), and not inserting an internal tag.
- As for satellite tags, we have changed from using fin-mounted SPOT tags on hammerheads to using towed PAT tag inserted with a titanium dart. We use the latter on hammerheads because it can be deployed quicker, although it doesn’t stay on the shark as long as fin-mounted tags (and so we have less data). Other sharks can tolerate the longer tagging process associated with fin mounted SPOT tags.
- Our hammerhead protocol allows us to usually sample, tag and release in less than 5 minutes once secured.
- Prior to release, we give the sharks vitamin E/Se and anti-inflammatory shots. This helps them reduce stress and recover faster upon careful release.

It is indeed a worthwhile cause to learn about the natural world as well as collect data that can conserve threatened species. Our work has shown, for example, that hammerheads are not a good candidate for catch-and-release fishing, that simply prohibiting the harvest of hammerheads or declaring a shark sanctuary will not be an effective tool to reduce hammerhead mortality to bycatch in many circumstances. Instead, our data suggests that gear modifications and/or place-based management (e.g. time-area closures, reserves) would be more beneficial for hammerheads (information that requires addition research from tagging and sampling). As far as management and policy is concerned, the onus is upon science to provide data that can be used to make effective conservation strategies. For example, our work is currently being used to develop best-practices guidelines for shark recreational fishing in Florida waters.

We will continue to research as well as publish and disseminate the results of our hammerhead research. In fact, watch for more hammerhead work from our lab, including a publication coming out shortly.

Those interested can learn more about our work here:

Anonymous said...

So you are using catch and release fishing techniques to determine that catch and release fishing techniques are bad for sharks. Well done.

DaShark said...

I'm with Neil on this one - u need to get the evidence in order to draw the conclusions - or not?

DaShark said...

Neil, chill brother.

Your quasi-simultaneous blasting of those kids and proud posting of your hooked GHH has raised quite a few eyebrows, and I appreciate you clearing the air with excellent information - or would you have preferred one of the usual underhanded whispering campaigns.

I for one am convinced that you go to great lengths in trying to minimize any harm to the Sharks, for which you need to be commended - the more as it appears that other researchers are clearly less squeamish!

Which of course begs the question, what's your guesstimate of the post release mortality of those GHH after implementing those protocols?.

As to whether comparing research and sport fishing is appropriate, or not.
For the majority of the public, fishing is fishing, and dead Sharks are dead Sharks, see the comment after yours - so instead of being offended, it may indeed be better to address their concerns, which you've done admirably in your comment.

Thanks, much appreciated.

My Hat has TWO Sharks said...


This ENTIRE debate was hashed out and settled in 1984 by Dr. Peter Venkman:

"Back off man...I'm a Scientist."

The shark research community has a media problem, because a picture says a thousand words.

In a society that increasingly does not read, but absorbs images at a voracious rate, images of researchers mugging next to sharks, fist bumping, and generally looking as if they are having the time of their lives with hooked animals leaves those who interpret images to build the narrative they choose.

The current narrative is, "research kids who fuck with sharks trying to tell us what to do."

The, "Back off Man....I'm a Scientist Syndrome."

As poorly as that line played out in 1984 it resonates to this day.

The solution is simple. Purge all images of "research kiddies with sharks" which include:

1. Bikini selfies with shark pups

2. In water selfies with hooked sharks

3. Any smiling gang sign, fist bump, shaka, or hand signal with hooked sharks

4. Group shots and videos with smiling staff, kids, and hooked sharks

5. Standing on top of, or next to, world record sized hooked bull sharks and then promoting said images to The Daily Mail, UK.

The list is endless really and by endless one has to play on Google Images for oh, about 30 seconds, to see it.

That being said, research is important. How about we do it (research) with the same sense of gravitas we would like others to exhibit when they sport fish sharks?

For that to happen might I suggest you start practicing the "Researcher Shark Scowl" and deploy it when you catch Hammerheads.

Or not.

Just remember, words ring hollow in the media world where the image is everything.

But you already knew that, hence the spread in The Daily Mail, UK.

Neil Hammerschlag said...

To Annonymous:


To understand the effect of A on B, one needs to test the effects of A on B.

Neil Hammerschlag said...


Thanks for the response.

I definitely appreciate the opportunity to proudly share the efforts we go to in oroder to promote animal welfare. I just would have appreciated you contacting me prior such that you could have included this information in your blog. For those that have inquired about our efforts, please feel free to share.

Based on what we can discern from our data so far, we have not documented mortality on animals that we have released with tags using the protocols presented above.



DaShark said...

Neil, I did in fact contact your lab prior to posting - but I wanted this to reflect the unease in public perception and have you guys address it, which is what has happened.

Neil Hammerschlag said...

My Hat has TWO Sharks,

The researchers and students you see in our pictures are indeed enthusiastic and happy..smiling while participating in meaningful and exciting hands-on research. As part of our outreach efforts, many of the kids we bring out on our research vessels are at-risk or underserved yourth that have never been on a boat before, let alone participate in real shark research. Moroever, my team and I love our work and truly enjoy educating the kids ang interacting with the mangificent animals. This is why you don't(and won't) see us with the "Researcher Shark Scowl" that you suggest we use.

For more information about our program and outreach efforts, check out:

My Hat has THREE Sharks said...


Heartwarming back-stories aside, the folks who you are demanding curtail their catch and release efforts could care less, even if you had a boat full at-risk and underserved Middle Earth Hobbits.

What they see is what your lab puts out.

You can try and couch your media sloppiness with as many back-stories as you choose, at the end of the day you will lose the narrative, just as the bikini gals lost their narrative once images of them riding the fins of GWS got out.

It's the long media bet.

The long bet says that contrary to best efforts at media narrative NO ONE reads the narrative,(as I am not going to spend any time on

I will instead continue to react to the steady stream of, "kiddies mugging with hooked sharks" and marvel at the supreme ignorance and arrogance of a supposed smart lab that wishes to impose it's will on others doing exactly the same thing - legally.

Either change your image suite or not.

The narrative is what the images says it is.

Hopefully you can "see" that.