SRC Program Questions

1. I’m really interested in joining the SRC Team. How can I get involved?

A: We have many opportunities to participate in the SRC Program depending on your age and specific interests. Learn more by exploring the Participate section on the website. We do not currently have any paid job opportunities.
2. I am interested in being a graduate student in your lab. Are you accepting PhD or Masters students?

A: SRC provides a platform for students to conduct research while enrolled as a graduate student at the University of Miami. Graduate students interested in getting involved with SRC projects while attending graduate school should contact Dr. Neil Hammerschlag. This resource may also be helpful. For more information on the field experiences available to graduate students, please visit: the Participation section of this website.
3. How can I make a donation to SRC? How can I adopt a shark?

A: Thank you so much for your interest in supporting our mission. We greatly appreciate it. You can make a secure online contribution by visiting the donation page of our website and following the on-screen instructions. Feel free to designate a specific cause (such as Student Scholarship, Educational Outreach, Research, etc). Adopting a shark costs $3000, and funds the purchase of a satellite tag. For the full scoop, please click HERE. We also have an online store where proceeds from purchasing cool shark apparel goes to supporting our program. Please check it out at: ShopForSharks.com, or check out our field shirts. Contact Neil Hammerschlag with any questions about donations at nhammerschlag@rsmas.miami.edu.
4. I am a teacher who would like to bring my students on a shark tagging trip with SRC. How can I arrange this?

A: Thank you for your interest in participating in our field research projects. We work with schools from all over the world and are always considering new partners. We expect our school partners to participate in 2-4 field experiences each school year as well as incorporating our high school curriculum into your classroom work. We also hope that your students will use our data in research projects that they can present at the SRC High School Science Conference at the end of the year. If you would like to become partners with SRC, please email umsharkresearch@gmail.com to discuss the possibilities.
5. I am a high school student who loves sharks and the ocean. Can I intern with SRC or attend a shark research trip?

A: While we would love to bring you out with us, we do not coordinate directly with with individual high school students. Instead, we work with high school groups, classes, and clubs organized by the supervising teachers. So please talk to your teachers about organizing a group, and then have one of them contact us at UMSharkResearch@gmail.com.
6. How can my class get involved if we are not able to join for SRC field experiences?

A: We offer a wide array of educational resources. For our comprehensive directory of virtual learning resources, please explore the link (right).
  1. Use our free high school curriculum
  2. Take a virtual expedition right from your classroom
  3. Track our sharks online
  4. Use SRC scientific data in class research projects
  5. Invite an SRC shark expert into your classroom for a presentation on a variety of topics
7. I am going on a shark tagging trip. What do I need to know before I go?

A: For the full story, please visit the Pre-Trip Checklist and make sure you complete all the required forms. Also explore the Virtual Expedition for a sneak peak at your day ahead. Here are a few quick tips:

Where? — We operate out of two different marinas: 4000 Crandon Blvd, Key Biscayne FL 33149, or 2560 S Bayshore Dr. Miami, FL 33133. We’ll notify which marine you’re leaving from.

When? — 8:30 AM meet-up at marina, 9 AM Departure, and expected arrival around 4:30 PM

Lunch? — Lunch is not provided. We ask that guests please bring a refillable water bottle, as we try to minimize our waste. We also encourage you to bring any snacks or preferred foods. For specific catering options, please contact umsharkresearch@gmail.com

Forms? — Please fill out and bring all forms listed here, based on which boat you’re going on – Waivers for Diver’s ParadiseWaivers for Field School

8. Do you provide corporate field experiences?

A: Yes. We would love to have your company aboard for a custom-tailored Citizen Science experience. For more information on corporate expeditions, please contact UMSharkResearch@gmail.com.
9. How do I keep updated about SRC activities and news?

A: We offer many avenues for staying in touch:

Shark Questions

10. What is a shark?

A: A shark is a fish, although sharks are different from other kinds of fish in several important ways, a few of which we’ll briefly discuss below.

Cartilaginous Skeletons

Unlike bony fish (also called “teleost” fish) sharks are cartilaginous. Try to bend your arm somewhere it is not jointed, and you will find it impossible without breaking the bone. Try the same with your ear or the tip of your nose and you will see the difference between bone and cartilage. There are some benefits to being cartilaginous: cartilage is both lighter and more flexible than bone. Some sharks are flexible enough to bite their own tails! However, there are also potential downsides—our bones play an important role in protecting our vital organs. Without a bony ribcage, sharks are susceptible to crushing or ramming injuries to their organs—a real danger when you are at risk of being caught in a net or hit by a boat.

Dermal Denticles

Instead of scales like most fish have, sharks are covered with dermal denticles. Dermal denticles literally means “tiny skin teeth”, and in fact each denticle is tooth-like in structure, containing a “pulp” of nerves covered by a crystalline structure of chemical called apatite, which helps make shark skin tough and strong. In the absence of a bony skeleton, this tough skin is critical to protecting sharks from predation and injury; denticles overlap closely that help provide protection from the bite of another shark and from miniscule skin parasites. Denticles make sharks even more hydrodynamic than they would be if they were completely smooth—the way denticles funnel water away from the body can reduce drag by as much as eight percent. Because denticles are much more efficient in displacing water, they also give sharks a stealth advantage. While the water displaced by swimming fish can be heard clearly on a hydrophone, a swimming shark is almost completely silent.

Shark Buoyancy Control

Most fish have what is called a “swim bladder,” a gas-filled organ that helps compensate for their weight and maintain them at neutral or near-neutral buoyancy in the marine environment. Sharks do not. Instead, sharks rely on their exceptionally large and oily liver (remember, oil floats on water) to help remain buoyant. Because the liver in most sharks is so large, most have shorter, more partitioned, intestines than other similarly sized animals, slowing their digestion and leading to more efficient nutrient absorption. Sharks are also helped to remain buoyant by their lighter cartilaginous skeleton and by the hydrodynamic properties of their body shape and fins (like a glider) and their unique dermal denticles discussed above!

11. I’ve heard sharks are primitive. How old are they really?

A: Ancestors of our modern sharks appeared on earth more than 450 million years ago, which means that sharks had already been swimming around for more than 200 million years before the first dinosaur walked the earth. They have survived at least five major extinction events that many or most other vertebrate species did not. Not only that, but they were an incredibly variable set of species even then: the total number of known species of dinosaur is approximately 800 species, while there are 2,000-3,000 known species of fossil shark! If that seems like a pretty wide-ranging estimate, it’s because many fossil shark species are identified based on as little as one tooth. Cartilage does not fossilize as easily as bone and so the fossil record for sharks is often incomplete.

Hominids, in contrast, date back no further than 4.5 million years – which means that even counting pre-human hominids, we have been on the plant for only one percent of the time in which sharks have swum in the sea.

12. How many kinds of sharks are there today?

A: There are more than 500 species of sharks (and more are discovered all the time) although most shark species pose no threat to humans, and bear little resemblance to the large predatory sharks people think of when they hear the word “shark”. They are incredibly diverse in appearance, ecological function and behavior. They are found in oceans all over the world—there are sharks that can live in fresh water, sharks that are pink, sharks that glow in the dark, even sharks that live under arctic ice! The entire elasmobranch family (sharks and rays) contains more than 1,000 species.

13. Why are you studying sharks? What makes them so important to ocean health?

A: Many species of sharks are what are called apex predators. “Apex” literally means “the highest point.” Apex predators are those with no predators of their own, residing at the top of the food chain. These top predators can exert what is known as “top down control” on the food web. More specifically, apex can impact the distribution and abundance of their prey most obviously by killing and consuming them. Also, by weeding out the weakest members of a fish school, sharks increase the likelihood that only the most genetically fit (largest, strongest, healthiest, smartest) fish will survive to reproduce However, apex predators can also impact their prey through “risk effects” (i.e. freighting their prey). By shifting their feeding areas or changing their feeding behaviors to avoid predators in response to risk effects, prey can subsequently impact the behaviors and abundance of other organisms, which can result in trophic cascades. Learn more about our work studying the ecosystem importance of sharks by clicking HERE and HERE.
15. How much have shark populations declined?

A: Multiple research methods have shown that some species of sharks have declined in population by 90% or more during the last several decades in areas where they were formerly abundant. For example, studies suggest that some hammerhead species in the northwest Atlantic have declined over 89% between 1986 and 2000. According to the IUCN Shark Specialist Group, 15% of all shark species and 1/3 of all open ocean shark species are Threatened, Endangered, or Critically Endangered. To learn more, please explore the links listed to the right.

15. How many sharks are killed by humans per year? What is the biggest threat facing sharks?

A: Sharks are killed by humans for many reasons. Most sharks are caught intentionally in commercial fisheries targeting them mostly for their fins (also see FAQ #20) and sometimes meat. Sharks are also caught each year unintentionally as bycatch in longline fisheries targeting large pelagic fish like tuna and swordfish. Some recreational fisheries also catch and kill sharks as trophies (in contrast to catch and release fishing). Sharks may also be impacted by humans more indirectly through threats like habitat loss, pollution, and human-driven declines in the fish species sharks rely on for food.

The data does not exist to exactly quantify the number of sharks humans remove from the ocean each year. One study, however, estimates that the fins of between 26 and 73 million sharks that are killed per year (some of which are from target fisheries, some of which were finned after being caught as bycatch) are sold in the Hong Kong fin market.

16. I want to become a shark biologist. Do you have any suggestions for me?

A: If you are interested in learning more about careers in marine biology and/or shark research, please click on the links provided in the boxes to the right. These are great resources that have specific details on advice for becoming a marine biologist or shark researcher.

If you do not find what you are looking for, please feel free to ask one of our shark scientists directly via Facebook.

17. I am passionate about sharks, and want to help save them. How can I help?

A: Every effort makes a difference! Here are a few easy ways to help both sharks and our oceans:
  1. Spread the word
  2. Learn more about sharks
  3. Consume sustainable seafood
  4. Avoid using plastic bags
  5. Recycle your trash
  6. Use circle hooks for catch-and-release fishing
  7. Avoid any products made from sharks
  8. Don’t eat shark fin soup
  9. Support reputable shark conservation organizations
  10. Support SRC’s marine conservation efforts
  11. Speak to your government representative
  12. Stay informed – you can keep in touch with us via our social media
18. What can I do to minimize my risk of shark attack?

A: The risk is already extremely small. The average American has a 1 in 5 chance of dying from heart disease, a 1 in 7 chance of dying from cancer, and a 1 in 3.8 million chance of being killed by a shark. However, there are a few basic common-sense strategies that swimmers and surfers can use to further reduce their chances of being bitten by a shark. Try to remain relatively close to shore and to other people. Try to swim during the day and not around dawn or dusk when sharks tend to be most actively hunting. Try to avoid areas near river mouths, as water there tends to be murky and some sharks like to hang out there, hoping a free meal will wash out to sea. Do not swim or dive in areas of unusually high fish density where sharks are likely to be feeding. Remember, you want to make it as easy as possible for a shark to identify what you are: a human being, not something they consider food. These are some suggestions gleaned from our years of knowledge, but SRC is not responsible for your safety. You are at your own risk when entering in the ocean. To learn more about reducing the risk of a shark encounter, click HERE.
19. Why do sharks bite people?

A: We don’t really know, but humans aren’t a primary food source for sharks. One of the leading theories is that most shark bites are a case of mistaken identity. It has been suggested that the outline of a surfboard being paddled by neoprene-wearing surfers looks an awful lot like a seal from below or the palm of a human hand or the sole of a human foot can easily be mistaken for the white belly of a distressed fish. The evidence suggests that most shark bites are accidents, where the shark mistakes a human (or part of a human) for something else. Some bites also occur when human swimmers or surfers accidentally step on a small shark resting on the bottom.

Many species of sharks are curious animals. When they come across something unusual, they want to learn more about it. If you or I wanted to know what something was, we’d pick it up and look at it more closely. Because sharks have no hands, they primarily use their mouth to investigate things they are curious about. When they mouth a human out of curiosity, we still perceive it as an “attack”—although in most cases it would be more accurate to describe it as an “accidental” or “experimental” bite. To learn more about why sharks may attack people, please click HERE.

20. Why do people eat shark fin soup? What is shark finning?

A: Shark fin soup is a traditional delicacy in Chinese culture dating back centuries. It was first consumed in Ming Dynasty China (1368-1644), by members of the Imperial court. As living standards in China have improved over the last few decades, shark fin soup has become increasingly accessible to the middle class. It is usually served at special, formal occasions like weddings, banquets and important business functions. Serving shark fin soup is considered to be good luck, but is also an important way to express respect for your guests and to honor them. It is also eaten as a cultural sign of wealth.

Shark fin soup itself has no color, taste, or smell and requires addition of chicken, beef, or pork broth to add flavor. However, the cartilage from the shark fin provides texture to the soup.

Tens of millions of sharks are killed annually for their fins and are being fished out faster than they can reproduce which is leading to several shark populations declines globally (See FAQ #14 & #15).

In recent years, many people in China and people of Chinese descent around the globe have become increasingly aware of the ecological problems associated with shark fin soup, and have begun arguing that it should no longer be consumed. Recently, the Chinese government announced it will no longer serve shark fin soup at governmental events.

Although shark fins are primarily consumed in Asia, shark finning (and fishing for their fins), is a global phenomenon. According to a recent report, 83 countries or territories supplied more than 10.3 million kilograms (22.7 million pounds) of shark fin products to Hong Kong in 2011. The top countries exporting fins to China include Spain, Mexico, and the U.S. More details can be found by clicking HERE.

Shark finning is the act whereby sharks are caught at sea, their fins are removed and kept, while the rest of the shark’s body is discarded at sea. Shark finning occurs mostly because shark meat is rarely consumed. In contrast, trading in shark fins is extremely lucrative. A single bowl of soup can cost hundreds of dollars. In several countries, including the United States, the act of shark finning is illegal, whereby the shark body is not discarded at sea. Instead, the whole body must be brought to shore before the fins are removed and sold.

21. Is consuming shark fins healthy or unhealthy?

A: A study recently completed by Hammerschlag and colleagues from the University of Miami revealed that shark fins contain high concentrations of a neurotoxin called BMAA, short for β-N-methylamino-L-alanine. BMAA has been linked to diseases such as Alzheimer’s, Parkinson’s and ALS. The study suggests that consumers of shark fins (and other parts) are at a risk of getting these neurological diseases. The study has generated tremendous scientific, media and public attention that will hopefully lower the demand for shark fins and also help protect people from diseases like Alzheimer’s, Parkinson’s and ALS. Click HERE to view the paper.
22. Are sharks worth more alive than dead?

A: In 2009, Palau declared their waters a “shark sanctuary” making it illegal to harvest sharks. They took this action not only because they recognized that sharks are ecologically critical to marine health, but because it made practical economic sense. It has been estimated that one individual living reef shark in Palau can generate up to $1.9 million in eco-tourism dollars over her lifetime, compared to a value of approximately $108 if she were killed for her fins (Vianna 2010). Moreover, in countries which rely on dive and marine-based tourism, the contribution sharks make to healthy marine ecosystems is important to the tourism industry. A study by SRC team members, Dr. Hammerschlag and Dr. Austin Gallagher, conducted a global analysis of all shark diving ecotourism and showed that the growing tourism industry can potentially generate more money over time for local economies than directly harvesting sharks for sale (Gallagher & Hammerschlag 2011). This and other similar economic analyses have helped prompt the creation of numerous shark sanctuaries and laws intended to help protect fragile shark populations. Here are a few the recent legal successes for sharks:
  • September 2009 — Palau created the first national shark sanctuary. No fishing of sharks is permitted within the national waters of Palau.
  • December 2010 — The United States passed the Shark Conservation Act, banning shark finning in US waters. This law means that shark fins cannot be brought to dock in the United States without the bodies of the sharks, dramatically limiting the number of shark fins a vessel can collect on each voyage.
  • June 2011 — Honduras created a shark sanctuary protecting sharks along both their Pacific and Caribbean coasts.
  • July 2011 — The Bahamas banned all commercial shark fishing within Bahamian national waters.
23. Does shark diving or chumming cause shark attack or negatively impact shark behavior?

A: While some concerns have been raised that shark feeding dives might cause sharks to associate humans with food, there is no scientific evidence that shark eco-tourism increases risk of shark attack. Research is ongoing into how to prevent ecotourism from disrupting natural shark behaviors, and protect sharks from behavioral changes that might put them at risk. Responsible and well-regulated shark ecotourism operators can play an important role in educating people about sharks and promoting shark conservation. A recent study, conducted by the SRC team, did not find that dive ecotourism effected the long term movements of tiger sharks in the Bahamas. Click HERE to learn more.

Research Questions

24. Does your research hurt the sharks?

A: Every aspect of our data gathering process is designed to minimize harm to our research subjects. We use special fishing and tagging gear intended to reduce stress, shorten handling time and promote shark safety. Please explore our Animal Welfare section of the website to learn more about the special protocols our team follows to promote shark welfare.


The Shark Research & Conservation Program uses special fishing units called drumlines (composed of a single weight and attached hook & line) that promotes shark vitality when fishing for sharks. The gear permits species which are ram ventilaters (need to keep moving to breathe) to swim in big circles around the weight when caught. The ability to swim relatively freely also minimizes stress-related C02 and lactic acid buildup in shark muscle. This gear promotes shark survival.

Circle Hooks

Circle hooks can help reduce negative outcomes for captured sharks over other commonly used hooks, most notably J hooks. Circle hooks are designed to catch in the shark’s jaw, instead of catching on the shark’s stomach or gills, which can otherwise cause serious injury. The hooks can also easily be removed from the jaw and leave a very superficial wound that heals very quickly. Circle hooks also help us selectively target sharks, reducing unwanted bycatch of other species. We recommend circle hooks not only for research-related capture, but for recreational fishermen practicing catch and release fishing who want to increase the likelihood of release their catches in good condition.

Workup Process

When a caught shark is brought onto a specialized, partly-submerged, platform on the back of our research vessel, a saltwater pump is immediately placed in the sharks’ mouth. This allows highly oxygenated water to flow over its gills throughout the shark’s brief ”check-up.” During this workup, sharks have a small muscle biopsy taken (recaptured sharks demonstrate that the biopsy site is completely healed within just a few weeks), are tagged with a spaghetti tag in their dorsal fin (where they have no nerve endings and no blood vessels), have blood drawn, are measured, have a small clip of their fin cartilage taken, and are released.

The traditional method for getting the type of data we collect was to kill the animals. Although capture may still be a relatively stressful process for sharks, our work focuses on minimizing shark stress to the greatest extent possible and promoting shark vitality and survival.

Our work has been proved successful with minimal shark stress. Our methods have been approved by the University Animal Welfare & Care Committee. It is also worth noting, that based on all available scientific evidence available, it appears that sharks do not feel pain.

25. Do sharks feel pain while you work them up?

A: Sharks have significantly fewer nerve endings than humans do. Humans have developed tremendously complex nervous systems with many millions of nerves as part of the process of evolution, these nerves “teach” us—through pain—what we should and shouldn’t do (don’t touch a hot stove). However, this level of sensitivity to temperature, pressure or pain has not been necessary for sharks. The nerves that report tissue damage and lead us to feel “pain” are neurons called “nociceptors” which account for approximately 50 percent of all human neurons, but only 13 to 38 percent of shark neurons and less than 1 percent of ray neurons. Sharks have many fewer nerves than we do, and devote a smaller percentage of those they do have to feeling pain. Therefore, although we don’t know exactly how it feels to a shark when we tag it, we can say for certain that they have neither the nerve endings nor the neurological apparatus to experience pain the way a human would. For more discussion on sharks and pain, please click HERE.
26. Do your tags cause fin damage?

A: All tags are not permanent. They fall off over time and the application point heals back quickly. Some of our satellite tags are temporarily attached to the shark’s dorsal fin. However, sharks have no blood or nerve supply to their fins. We’ve also recaptured satellite tagged sharks after months at liberty, and their fins appeared undamaged. The potential effects on the sharks are minimal considering the research and education it provides, which will help protect these threatened species. For more information, please read our paper on satellite tags, which further discuss the potential for negative impacts on sharks (right).
27. Why does a shark transmission stop?

A: Satellite tags are essentially fancy computers attached to live sharks. There are a number of things that can happen to a tag once it is released.
  • In order for a tag to transmit the shark must break the surface of the water. This can sometimes be infrequent and sporadic.
  • Our tags are equipped with enough battery life to sustain up to a year of transmissions. However, this number is variable depending on the frequency a shark transmits. More transmissions will cause a tag to lose battery quicker.
  • Satellite tags are designed to eventually pop of a shark so the animal is not swimming with it indefinitely. The tags are attached using titanium that will corrode in saltwater; the length of the corrosion process varies with conditions in the water such as salinity and temperature.
  • As a shark heals the tag can actually get pushed right out of the fin.
  • As the tag travels with a shark it can accumulate algae and other organisms. This can block the tag and prevent it from successfully transmitting.
  • As sharks go through life there is potential for collision. For example, run-ins with other sharks or getting caught in a coral reef can break the tag and prevent transmission.
28. Can satellite tags interfere with shark electromagnetic senses?

A: There is no scientific evidence that satellite tags interfere with shark senses. Based on data from our satellite tags, it appears that tagged sharks are able to swim, hunt, migrate and participate normally in all natural shark behaviors. We would expect a much higher level of morbidity and mortality among tagged sharks if the satellite tags interfered with their sensory systems. For further discussion, click HERE.
29. Does posting shark tracks online help fishermen find and exploit sharks?

A: No. Although this is a concern raised by shark conservation advocates, the reality is that fishing is everywhere. Except where they are already protected and properly managed, there is no place where sharks are safe from fishing. The fishing industry is way ahead of scientists in terms of knowing where the sharks are. Sometimes, the fishing industry even hires oceanographic data analysts to identify potential fishing “hot spots” in real time, reporting these locations to fishers at sea. It is scientists that are playing catch up and the tracking data generated is used to help managers make informed conservation decisions. To us, the tracking data not only helps conservation management, but the educational benefits of free, interactive online shark tracks we post helps generate public awareness and support for shark conservation.
30. What can scientists learn from satellite tagging sharks?

A: Satellite tags allow scientists to study the migratory routes and residency patterns of sharks. This data can be used to identify areas that are critical for shark mating, giving birth and feeding as well as locations where sharks are vulnerable to destructive fishing. These data can help policy makers implement effective management strategies that will improve conservation for threatened shark species. To read some recent scientific papers using satellite tagging, click on the boxes to the right. To learn more about SRC’s satellite tagging research, please click HERE.