The Importance of Movement

Written by Dr. Michelle Heupel

There are a lot of people studying shark movements these days. It seems like most conferences I go to or web sites I visit have a heavy tracking focus. This is interesting to the handful of us who have been doing this for a while – suddenly what we do is really popular! So why do people track sharks? Some of them do it because it’s cool and interesting, but ultimately it is hopefully useful for more than scientific curiosity.

I have spent the last 15 or so years tracking sharks – why do I do it? Although I also think tracking is cool, fun and interesting my tracking research started out trying to answer a specific management based question: how long do juvenile sharks stay in a nursery area? That research told us how dependent they were on that area and how important it was for their survival. Since then I have done a number of projects that looked at how sharks use space relative to marine protected areas. The driving question: how much is an area that is closed to fishing protecting sharks? To answer that we have to think about how long sharks stay inside the protected area and how often they move in and out.

One of my students, Danielle Knip did a really nice analysis of closed area benefits for pigeye and spottail sharks in a north Queensland bay. What she found was that over the course of 2 years these sharks only spent 22-32% of their time inside the protected area. That means they weren’t getting much protection from fishing. It was an interesting finding but the closed area wasn’t actually designed to protect coastal sharks so we weren’t totally surprised to see such low levels or protection.

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A pigeye shark (top) – a close relative to the bull shark, and a spottail shark (bottom). The two species were tracked to see how long they stayed inside a marine protected area.

More recently I’ve been tracking reef sharks to see if protecting a reef protects the sharks that use it. The answer: it depends. That’s a scientist answer for you. We never want to say yes or no until we tell you the whole back story. In this case though, the “depends” actually relates to the species of shark. For species that spend a long time on the same reef they can get a lot of protection from closing their reef to fishing. For example, Mario Espinoza and I recently showed grey reef sharks can spend years on a single reef based on data from two separate sections of the Great Barrier Reef. However, if they spend a lot of time on a reef that isn’t closed to fishing they may be more exposed than average because fishing pressure might be directed to that reef due to closed areas. Things that move more widely though, like tiger sharks, silvertip sharks and bull sharks get much less value from closed areas because they move so much.

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Map showing the movements of a female 188 cm tiger shark moving between coral reefs. Reefs in blue and yellow are open to line fishing, green and pink are closed to fishing. Blue triangle and red square indicate the beginning and end of the track.

So what does all this mean? It means we can’t just use closed areas to protect sharks – a lot of them just swim right out. We have to use other management measures like catch limits to help protect them. The other thing this means is that we really do need to understand how much the animals we are trying to protect move. How long they stay and where they actually go are critical to our ability to get management right.

Papers related to this story:

Heupel MR and Simpfendorfer CA (2015) Long-term movement patterns of aoral reef predator. Coral Reefs 34: 679-691

Heupel MR, Simpfendorfer CA, Espinoza M, Smoothey A, Tobin AJ and Peddemors V (2015) Conservation challenges of sharks with continental scale migrations. Frontiers in Marine Science doi: 10.3389/fmars.2015.00012

Espinoza M, Heupel MR, Tobin AJ and Simpfendorfer CA (2015) Residency patterns and movements of grey reef sharks in a semi-continuous reef environment: evidence of reproductive behaviour. Marine Biology 162: 343-358

Knip DM, Heupel MR and Simpfendorfer CA (2012) Evaluating marine protected areas for the conservation of tropical coastal sharks. Biological Conservation 148: 200-209.

Cape fur seal white shark research EDNA Science Dyer Island Conservation Trust

Infographic: How seals use subsurface structures to sneak by white sharks

Written by Michelle Jewell.  Follow her on twitter: @ExpatScientist

If you have ever avoided parking on a risky-looking street or taken a different route between classes to avoid a bully, your behaviour has been altered due to the perceived presence of ‘predators’.  In the wild, prey animals also change their behaviour when they think predators are around, and these altered anti-predator behaviours can often influence other species, and then influence more species, and eventually change the entire ecosystem.  This is an example of indirect effects predators have on ecosystems.

My research has focused on these principles of predator/prey interaction in the ocean, and a great place to study oceanic predators and their prey are Cape fur seal colonies in South Africa.  Every summer in the southern hemisphere (November), Cape fur seals give birth to thousands of pups.  For example, the seal colony Geyser Rock has a population of about 60,000 Cape fur seals and every year they give birth to 10,000 seal pups!  By winter (April – September) these 6 month old ‘young-of-the-year’ seals begin to venture off the colonies and swim offshore with the adults to the fishing grounds.  These young-of-the-years are typically slow, plump from months of a mostly fat milk diet, and – most importantly – naïve.  White sharks take advantage of this naivety and aggregate closely around seal colonies every winter to catch leaving/returning seals.  Young-of-the-year pups are forced to learn how to avoid sharks quickly or suffer some rather permanent consequences!  This means that during a full year, every seal colony goes through a period of high white shark presence (winter) and very low to no white shark presence (summer).  Therefore, we can see how seals act ‘normally’ during the summer when there are no/very few sharks and how they change their behaviour in the winter to avoid white sharks.

Dyer Island Geyser Rock Shark Alley South Africa Seal Island False Bay

A) The Western Cape of South Africa with B) Seal Island, False Bay and C) Dyer Island & Geyser Rock.

Also, there are many different kinds of seal colony islands along the coast, which lets us ask more questions about how seals use their environment to avoid sharks.  I conducted my study at the Dyer Island/Geyser Rock system, which is home to ‘Shark Alley’ as well as many shallow reefs, kelp forests, and shipwrecks.  About 100km to the east is another seal colony called Seal Island, which is a world-famous spot to see white sharks predate on seals, but this island system lacks the abundant nearby structures/reefs/kelp forests that are present at Geyser Rock.  By looking at these two different kinds of islands, we can also examine how structures – or ‘refugia’ – may alter how seals avoid white sharks at Geyser Rock from how seals avoid white sharks at Seal Island.

And here’s what we found…

Agents of seal cape fur white shark research dyer EDNA Science

Do all of these structures and anti-predatory tactics of Cape fur seals change white shark movements around Geyser Rock?  Most definitely!  Check out that study (and infographic!) here.

This project was funded by the Dyer Island Conservation Trust and supported by Marine Dynamics shark tours, Volkswagen South Africa, and OCEARCH.  The infographic was designed by EDNA Science.  You can read the detailed scientific publication on Behavioral Ecology & Sociobiology by clicking here.

Have a question?  Leave it in the comments and I will answer!

Your Starting Point Doesn’t Matter

Written by Dr. Michelle Heupel

When I was 14 I decided that I would be a marine biologist, not just any marine biologist, a shark biologist. This was before I saw the ocean for the first time. A whole bunch of people just said “what?” No, I’m not confused, this is how it happened. And yes, almost everyone said I was crazy.

My point in this blog is to say that it doesn’t matter where you come from, you can be who or what you want no matter what your starting point. All you have to do is apply yourself and go for it. So where do I come from – where did I start? I grew up in South Dakota until I was 14 when my family moved to Colorado. Very solidly in “the middle” of the US – no growing up on beaches for me. I don’t know where the decision came from to go study sharks, it was just there.

So how did I manage getting from the middle of the US to becoming a shark researcher? Two main ingredients: support from my family and hard work. My parents are amazing. While everyone else was telling me I was crazy they consistently said – don’t listen to anyone else, if this is what you want to do then put your head down and go do it. One of the most vivid memories I have from high school has to do with this support. I went to the guidance counsellor to ask for some material about colleges and told him I wanted to study marine biology. He told me I would never make it, would never get a job and that I should change my senior year classes so I could become a bookkeeper or accountant. I went home in tears. My Mom happened to be home when I walked in that day (she was usually at work) and she asked me what happened. I told her the story and she asked who had told me this. She then phoned the school, asked for the counsellor and proceeded to tell him off. I clearly remember her saying “Don’t you dare tell my kid she can’t do something she wants to do!” She then hung up the phone and said to me, “don’t ever listen to people like that, if you want to do it, go do it”. Several times this journey has gotten difficult and I have considered quitting. Each of these times my family has been there to support me and encourage me to keep chasing my dream. To say my family have been crucial to my success would be a huge understatement.

michelle kid

A photo of me from South Dakota holding a sunfish I caught in one of the local lakes.

So, if you don’t have someone in your life who will tell you the things my family has, find someone who will, or let me be that person. Do not give up on yourself, do not give up on your dreams and goals. Work hard and give it your best. If it doesn’t work out at least you know that you gave it every chance.

So here I am, a shark biologist with almost 20 years of experience in the field and sometimes I wonder – who was the crazy person all those years ago? I don’t think it was me.

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I’ve moved on to fishing for bigger things – fishing for blacktip sharks in the Florida Keys

A Typical Day on this Research Cruise

Written by Helena Aryafar

*Helena tags and collects biological samples from juvenile and adult blue sharks on federal research cruises

5:30 a.m. (~sunrise)-6:30 a.m.  Set the longline gear (Set 1) 
Setting gear requires baiting the hooks (~200 per set), putting lightsticks above each hook (these attract fish to the bait in the deep dark waters), throwing the line out into the water, and attaching and releasing buoys to separate baskets of hooks.  This process usually takes around an hour to an hour and a half.  This will be set #1 and will soak (soak = stay in the water) for 10 hours before we haul it back on deck.  Immediately after set #1, we will motor to another area to do 1-2 shorter sets that will only soak for ~2 hours each before we haul the gear back. 
Buoys and radio beepers (used to find the longline gear for haulback)

Buoys and radio beepers (used to find the longline gear for haulback)


8:30 a.m.-9:30 a.m. Set the longline gear (Set 2)

9:30 a.m.-10:30 a.m Prepare tagging and sampling gear for haulback; deploy CTD (Conductivity, Temperature, and Depth device)–CTD provides us with information about the habitat in which we are fishing
The set-up for haulback and sampling

The set-up for haulback and sampling

Electronic tags

Electronic tags


10:30 a.m.-12:00 p.m Haulback of Set 2

When we are ready to haul the gear back on deck, the main line will be pulled back onto the spool and each hook is removed and put back into a large bin to be used for setting the gear next time.  As the animals come up, we assess the condition of the fish, pull them onto a cradle that gets hoisted onto the deck with a hydraulic winch, and begin working up the animal.  Sharks will immediately get a ventilator (hose with specially fitted mouth piece) to run water over their gills, a wet chamois or towel is used to cover their eyes (which keeps them calm), and the hook is removed.  We take length measurements and determine sex of the animal (claspers vs. no claspers).  A small corner of the dorsal fin is clipped and saved in alcohol as a DNA sample, and depending on the size of the shark and which project we want to use that sample for, either a conventional tag (a thin piece of plastic that contains a unique ID number and contact information for fishermen to use in the event of recapture of the animal) or an electronic tag (that provides data on location and movement patterns) is inserted near the dorsal fin.  We will also be taking blood samples to measure lactate levels, which can give us information on the stress level (condition) of the fish. Some of the sharks will also receive a secondary tag (with reward information for recapture) and antibiotics that function as a marker of when they were captured and can be used to determine age and associated growth of the shark if it is recaptured in the future and the vertebrae are returned to our lab.  Once the sharks have been tagged and/or sampled, we return them to the water and assess condition once again.  Sharks that are not alive upon haulback of the longline will be processed for biological samples that include: stomach (can be used to determine what the shark has been eating and which habitats it exploits), liver/muscle/heart tissues (used for stable isotope analysis which can tell us about its movements and where it spends a lot of its time), and gonads (used to determine maturity and provide information on reproduction).      

Tagging

Tagging

Ventilated male shark with a roto tag and conventional tag just before release

Ventilated male shark with a roto tag and conventional tag just before release

1:00 p.m.- 2:00 p.m. Set the longline gear (Set 3)
3:00 p.m.- 4:30 p.m. Haulback of Set 3
5:30 p.m.-7:00 p.m. Haulback of Set 1

Repeat for 10 days and pepper in some tagging of opah and swordfish. Rough seas, long days, hard work, and lots of fun!

My bunk for 10 days...pretty cozy

My bunk for 10 days…pretty cozy

Science Saving Sharks

Written by Dr. Michelle Heupel

How are scientists helping to save sharks?

There is a lot of information on the internet about sharks and how to save them. Some of it is good, some of it is bad, some of it has a purpose, some of it has none. I’m starting to sound like Dr.Suess with all of this, but this is how things are in our world of increasing internet and social media. So there seems to be a lot happening and a lot of people involved in the cause. This is great because getting people to understand the problem is one way to create solutions, as long as what we tell them is correct.

So what is my role in all of the workings of shark (and ray!) conservation? My job is to create information. This is one of the best parts of my job – getting to learn things that maybe no one else in the world knows. What then? Then I need to get the information written up and published so others can use it and learn from it. This isn’t just about telling other scientists what I learned, this is also about making sure people who make decisions about management get the new information if they need it.

There are so many questions about sharks and rays. So many things we don’t know. For some species we don’t know how long they live, how many pups they have, how far they swim, and even how many are there. We need all of this information. People who decide if it is ok to fish sharks and rays, or whether we need to make a marine protected area, need this information. If they don’t know these answers they can’t make good decisions because sometimes they’ll have to guess what to do. My job is to give them the answers so they don’t have to guess (as often, we still have to guess sometimes). This same information is also used by conservation groups. If a manager makes a decision that doesn’t match the scientific information then the conservationists can use the information I provide to try to change the decision.

So, it seems like I sit outside of all the action doesn’t it? I don’t make the decisions and I usually don’t challenge the people who make the decisions. Those are other people’s jobs. My job is to get the information or ammunition needed to argue or make decisions. So, does someone like me ever really make a difference? You bet. Work I did to define what a shark nursery is has been used to save habitat for Endangered smalltooth sawfish. My science is listed in the Federal Register in the protections for sawfish, a real world result of my science! My data from studying mortality rates of blacktip sharks has been used to adjust the number of blacktip sharks caught in US fisheries. This was an unexpected outcome of one of my projects, but one that proved very useful to managers. These two examples are not the things my research is most known for, but they are some of the bits I am most proud of – times when science made a difference.

Times are complicated and our oceans are damaged, but with hard work and good science I hope to continue to make a difference where I can. We need more answers to save sharks and rays, and that means we need more science.

Dr. Michelle Heupel releasing a young blacktip shark in Florida

Dr. Michelle Heupel releasing a young blacktip shark in Florida

An endangered smalltooth sawfish from southern Florida

Shark Education, Shark Diving and Shark Filming

Written by Jillian Morris

The last twelve years of my life have been heavily influenced by sharks. During my time at University I did an internship with Mote Marine Lab, which opened my eyes to the incredible world of shark science and research. I was hooked; pun intended! From there I continued to gain experience working as volunteer with the Bimini Biological Field Station and then later as a research assistant with the Shark Bay Ecosystem ResearchProject. I became a dive instructor along the way and always had a camera with me. These experiences merged and evolved into my career as a videographer and photographer.

I am currently based in the Bahamas where I am able to dive with and film sharks in my backyard. My husband Duncan and I run a conservation media company called OceanicAllstars with a focus on shark education and conservation. We have traveled the world to film and dive with sharks. Our goal is to share the beauty of these animals with as many people as possible. They say an image is worth a thousand words, so a video can be even more powerful. Media stereotypes include the monster mentality of sharks far too often, so we are hoping to provide the audience with a different, more realistic perspective. With this approach our images and videos become an educational tool, which has lead to the creation of Sharks4Kids.

Sharks4Kids is a Florida based non-profit that I started working on in 2008. I wanted to create educational materials not only for students, but also guides for educators, so they would be more inclined to introduce sharks and shark conservation into their curriculum.  I worked to collect images, videos and experiences that I finally brought together in 2013 and launched our website. Duncan and best friend, Dr. Derek Burkholder helped make my dream a reality and at this point we have connected with over 10,000 kids in 20 different countries both in person and via Skype to share shark education. My happiest moments are sharing sharks with kids, seeing their optimism, empathy and excitement. The world of shark conservation can be frustrating and heartbreaking on the best days, but kids give me hope. Hope for a future where we still have sharks in our oceans.

Each day is different and whether I am filming sharks for a BBC shark program or helping the Sharklab with a project, my main goal is to spread the message of shark conservation to as many people as possible. We can all make a difference and we can all do something, no matter how old or young.

llian filming a great hammerhead in Bimini. Photo by Grant Johnson

Jillian filming a great hammerhead in Bimini. Photo by Grant Johnson

Jillian tagging a tiger shark in Shark Bay, Western Australia

Jillian tagging a tiger shark in Shark Bay, Western Australia

Jillian speaking to kids in Guelph, Ontario about sharks

Jillian speaking to kids in Guelph, Ontario about sharks

Duncan and Jillian diving with Caribbean reef sharks. Photo by Deano Cook

Duncan and Jillian diving with Caribbean reef sharks. Photo by Deano Cook

Jillian measuring a bull shark with the Bimini Biological Field Station. Photo by Grant Johnson

Jillian measuring a bull shark with the Bimini Biological Field Station. Photo by Grant Johnson

SHARKS INTERNATIONAL 2014: A pivotal forum for science and conservation collaboration

Written by Hannah Medd

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Hannah Medd

Approximately 275 students and professionals from 40 countries descended upon Durban, South Africa, during the first week of June, 2014, to talk SHARK! The 2nd annual SHARKS INTERNATIONAL scientific conference was recently held over 4 days of about 80 talks on all aspects of elasmobranch research including acoustic telemetry, physiology, tourism, genetics, tagging, age and growth, fisheries, sensory biology, population ecology, Baited Remote Underwater Video Systems (BRUVS), trophic ecology, sawfish, social research, management, and shark control. It was a shark nerd’s dream and I jumped at the chance to go! Having attended graduate school in South Africa, it was a long awaited homecoming but also a rare opportunity to network with peers working around the globe, exchange ideas, collaborate, and finally meet face to face.

The talks were only 15 minutes long, which is not a lot of time to present the breadth of your work that for many is decades in the making so most presenters focus on their innovative methodologies or the latest results or most impactful applications. To further inspire the Gills Club members (not that the guys didn’t perform admirably) I noticed some impressive presenters that just happened to be ladies! Dr. Alison Kock, a Gills Club Scientist and Research Manager at Shark Spotters based in Muizenberg, South Africa, gave an impressive talk on her research on the white sharks of False Bay, South Africa, revealing the sharks demonstrate high levels of site fidelity (they really like to hang out in specific spots) to inshore areas which will affect how Marine Protected Areas will be designed. Charlene da Silva, shark researcher for the South African Fisheries Department, gave a funny and dynamic talk on the chondrichthyan fisheries of South Africa, the lack of data on economically important species and the immediate need for sustainable management. Rachel Graham, Executive Director of Mar Alliance, spoke on monitoring sharks using many different methods in Belize to establish a baseline which is incredibly important in informing conservation planning. Lauren De Vos, a PhD student from the University of Cape Town, spoke about her work using BRUVS (Baited Remote Underwater Video Systems) to assess abundance of sharks in different habitats. Alison Towner, a PhD student, described her work tagging and tracking great whites in Gansbaai, South Africa, to determine what environmental factors influence the sharks’ movements by collecting data on cage diving boats. Ana Sobral, a Portuguese researcher, represented the rays by presenting her work on the aggregating Mobula tarapacana near the Azores. Ana is developing a photo identification program based on the color patters on the rays’ stomachs to better understand the population dynamics of these little-studied rays. Sarah Fowler, the Vice-chair of the IUCN Shark Specialist Group, a legend in shark research and conservation, demystified the seemingly overwhelming process of listing vulnerable species on international treaties such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The formidable Sonja Fordham of Shark Advocates International clarified some common misconceptions about global shark conservation that can be spread by reporters and well-meaning concerned citizens, while encouraging a focus on the real threats to the vulnerable species, charismatic or not. These ladies represent a snippet of the incredibly impressive and inspirational female talent demonstrated at this conference.

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Charlene Da Silva

DSC_1273                                                                          Ana Sobral 

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                                                                                       Alison Kock 

The take home message was that shark research needs to focus on species other than the big, charismatic species like whale and white sharks and it needs to employ innovative techniques to achieve goals for broader conservation impacts. It was so encouraging to see and meet new fresh faces that are so dedicated to understanding the importance of sharks and rays to our ocean ecosystems as well as to learn from those professionals that have plowed the way for better research and conservation. From the welcome cocktail party, including fabulous Zulu dancers, to the each evening’s event, through the manic tea breaks, Sharks International 2014 was definitely considered a success!