Wednesday, February 26, 2014

Non-invasive tagging of Sharks!

NIMBY! Source.

Watch this.

As I said, it's a good thing.
Winram's comments to that video mention Austin's paper, and the whole exercise is being depicted as some major change of direction in Shark tagging, which I would of course applaud.

Just this.
We've been doing just that from day one = 10 years ago.
Literally from the very first time we've met to discuss how we could work together, Juerg has made it a point that he wanted to utilize the least  invasive techniques possible. Consequently, and despite of the obvious increased risk of losing the tags (and lose them we sure did!), we've decided to attach our PAT tags and acoustic tags exclusively underwater. And more than that: because of my personal aversion against leaving those anchors in the Sharks, we've even experimented with hiding tags in Tuna heads and then feeding them to the animals, alas with mixed results. 
In fact, and to the great chagrin of several people, we have not tagged a single Shark for the past five years pending the development of less invasive attachments.

Whereas I see no problem with catching those babies (and here), we will never hook and haul up any Sharks within the SRMR, ever.
And that's a promise.

Anyway - nice to see that others are catching up!
Just sayin'! :)


Megalobomb said...

In regions where you can safely swim up to your study species and tag it, I see no reason why you would do it any other way. Unfortunately, not all sharks swim in beautifully clean Fijian/Caribbean waters :)

DaShark said...


Let's c what comes of it - it looks like a no-brainer but as always, the proof is in the pudding!

Neil Hammerschlag said...

I agree that such type of non-invasive research is useful. However, like Megalobomb said, this is a site of aggregating hammerheads that can be lured in and tagged. This is not usually the case. Also, such a technique depends on the research question. Our goal is not to simply tag, but do a standardized shark survey and answer a variety of questions that require taking samples that can't be done underwater. Moreover, different tags answer different questions, acoustic tags vs ID vs PAT vs SPOT tags give very different types of data. Different questions require different tools and different techniques which will also be influenced based on location and species.

It is also worth noting that most sharks are robust and can handle capture and handling for research, as our stress physiology work has shown. For example, tiger sharks are extremely hardy and can pretty much handle anything.