Last week, I wrote about National Geographic’s Expedition Great White. In that post, I mentioned that the practice of removing great white sharks from the water for research was controversial, and that I would ask the lead scientist in the show about it. Here are answers to my questions from Dr. Michael Domeier and his colleague Nicole Lucas. They also wanted me to point out that their website has an FAQ page about this technique, which can be found here.
WhySharksMatter (WSM): Many people are concerned that pulling such a large animal out of the water can be dangerous for that animal. Should we be concerned?
Michael Domeier/Nicole Lucas (MD/NL): We know that whales can sometimes incur internal injury when they get stranded on the beach, so this issue was a concern. Fortunately sharks are much smaller than whales, and we started out by testing our methods on relatively small sharks. Our early success allowed us to slowly start working on larger and larger sharks and likewise found that they go through the tagging process without serious injury. We could run into problems if we captured a female with a late-term pregnancy, but we target females at sites and times when they are not pregnant.
WSM: Is it possible to get the data you obtained via pulling the shark out of the water using different methods?
MD/NL: Unfortunately no. We have been using pop-up tags for over 10 years and have exhausted what we can learn from these methods. The location data is not precise and they only give 9 months of data. Using acoustic tagging only gives you information where you have a receiver so that can’t give us the answers to the questions we are asking either. We are looking at large scale long term movement patterns so this technology is ideal. This is especially important for tracking the mating and birthing areas for the females which have a 2-3 year migration cycle.
WSM: Is that data important?
MD/NL: The more we know about these sharks that more we can protect them, and there is still much that we don’t know. This is especially important since they cross international boundaries and we are dealing with mating areas, pupping areas and nursery grounds. These are particularly sensitive areas that need to be protected.
WSM: Have any great white sharks been harmed using this method?
MD/NL: We had an incident in the Farallon Islands where a hook was lodged in the back of the mouth and was difficult to extract. For obvious reasons, you can’t simply reach down into the mouth of an adult white shark and work the hook out. In this case we had to go in through a gill slit and cut the hook in half with bolt cutters. We couldn’t reach the rest of the hook, but after cutting it, it should have easily fallen out so that it could be expelled from the mouth. This particular shark made its normal migration pattern to the middle of the Pacific Ocean, to the SOFA, and 8 months later we are still getting regular messages from this shark, so we know for a fact that it is alive and well. We have now modified our fishing methods for water with very poor visibility so that this can’t happen again. In short, we fish the bait right at the surface so the shark must turn away as soon as it takes the bait, immediately setting the hook in the mouth or pulling it free.
WSM: Even if the animals swim away safely, sublethal effects are a possibility. Since we know so little about these animal’s behavior, is there any way that we could detect those sublethal effects if they were occurring?
MD/NL: As with any tagging study there will be short term sublethal effects. The shark will have undergone stress from which it must recover. Our tags do not allow us to determine the length of the recovery period, but it is likely a matter of hours, a few days at the most. From our popup tagging studies we know for a fact that all of our SPOT tagged sharks are following there normal, seasonal migratory patterns. One interesting anecdote, we once caught the same shark twice in a matter of hours; that should provide some indication of the minimal effect we are having on the shark.
WSM: The show continually mentions that as long as the sharks are back in the water within 20 minutes, they’ll be fine. Where did that number come from?
MD/NL: We don’t write the script for the program and I’m not sure how or why that number is do deeply ingrained in the story telling. I think, perhaps, it is because I had known that white sharks had been restrained for that long previous to our work and the animal survived. Twenty minutes is an arbitrary number; our goal is to get the shark back in the water ASAP, and that is usually in much less time than 20 minutes.
great interview David!
I agree with DNLee – good interview. It clarified several questions that I am sure many people who have watched the series have had. I find it interesting the reaction that some have to this series – the extent to which it might cross over lines that certain investigators may feel could be out of bounds, balanced against trying to find innovative ways to communicate science more effectively, and to hopefully motivating a general(Internet-literate) public– that is almost numb from information overload–to take interest and hopefully to care more about the plight of sharks (and other species). I found this interview from 60 minutes to be a very interesting commentary by Robert Ballard on this very point and how he has chosen to operate: http://www.cbs.com/primetime/60_minutes/video/?pid=bjGtQhnqc1zo8U2IBpHdpVeKitLT11zf&nrd=1
I thought the answers to your questions were genuine and straight forward. I also found it informative that there seems to be limits to what the investigators can influence with the script writers. Thanks for posting!
I really enjoyed watching expedition great white, I think what Dr. Michael Domeier is doing for the species is great. I don’t disagree with removing the sharks from the ocean via the raising platform as they take great care in what they do not to harm the sharks and safely release them. Thank you for all that you do. <3
I have no problem with them pulling the sharks out of the water. They are doing this to study and keep the shark protected over time. I have a problem with ESPN showing fishing shows where they pull in giant sharks, killing them for no reason. That is more of a problem.
I agree we need more data on sharks because the more we know the more we can protect them and what we know today is so little. The information we have today is pretty much the same information we had 20 years ago. However, with that said, what we do know is that our White Shark population here in California is an isolated gene pool, which in itself makes the population fragile. We also know that this Californian isolated population is small, somewhere between 170-219 sharks total estimate. Those facts along with how many years to reach sexual maturity and a long gestation period means that even harming one shark can be detrimental to the entire population. Domeier tagged 2 sharks out at the Farallon Islands last year, harming one of them as described above and this year hopes to tag 11 more. Again, I agree we the need research but I believe we can attain much of this information with less invasive tactics much like Sal Jorgensen has from Stanford University. Is the research more important or the shark?
I feel that the amount of speculation offered by this scientist in this EA or proposed action does not warrant endangering a protected resource, like the white shark.
Despite the fact that they swam away in the past, we do not know
1. Whether any hook material left in the shark will eventually lead to infection, cyst formation, necrosis or even death. This process may take years to manifest.
2. We do not know whether the shark is pregnant when brought onboard and the extent to which early-term pups are damaged as a result of the sharks own weight (which is likely well over 2 tons).
3. We do not know for certain that the observed migrations are “ordinary or expected behavior”. Sharks can go months without feeding due to the size of their fatty livers, thus there is no way to know how this traumatic experience is affecting the animals everyday activity.
4. We do not know how many generations are being affected by this research activity. Is this activity affecting mating, or some other aspects of this sharks existence.
Lastly, this is a protected resource that is not being commercially or recreationally fished due to its threatened status. How will this work help “save” the white shark when it already receives full federal and state protection from everyone except this scientist.
concerned citizen and supporter of the GOFNMS
muito boa seu trabalho gostaria de saber mais sobre o guindaste que usam no barco da expediçao shak na busca e captura desses reis dos mares imprensionante seu trabalho.
I agree that we need to utilize safer, more ADVANCED techniques in understanding…AND protecting these BEAUTIFUL, MAGNIFICENT creatures. Kudos to Dr. Domeier and his RESEARCH TEAM for the dedication in their efforts to “unravel” the mystery where “OTHERS” continue using the same methods of years past. Keep up the great work…and wish you MUCH SUCCESS in your endeavors!!