Neil Hammerschlag

Neil Hammerschlag

Research Assistant Professor , Marine Affairs & Policy

University of Miami
4600 Rickenbacker Causeway
Miami, FL 33149

Collier 206

Tel: 305.421.4356

Lab Website


Google Scholar Profile

My research centers on the behavioral ecology of marine predators. My current research has two main foci: (1) understanding how predator-prey interactions structure communities, particularly those involving sharks; and (2) determining habitat use and migratory patterns of large coastal sharks using satellite technologies. Other research interests include understanding how toxins biomagnify up the marine food chain. The goal of this research is advance ocean conservation through science. As part of my work, I am also interested in developing and implementing unique outreach and education programs for students, providing them with practical-hands on field and virtual experiences in marine conservation research.

Gallagher AJ, Hammerschlag N, Shiffman DS, Giery ST (In Press) Evolved for extinction: the cost and conservation implications of extreme specialization in hammerhead sharks. BioScience

Gallagher AJ, Romeiro J, Canabal D, Canabal V, Hammerschlag N (In Press) Novel social behaviors in a threatened apex marine predator, the oceanic whitetip shark Carcharhinus longimanus. Ethology Ecology & Evolution 00:000-000.

Shiffman DS, Hammerschlag N (In Press) An assessment of the scale, practices, and conservation implications of Florida’s charterboat-based recreational shark fishery; Fisheries

Cooke SJ, Hogan ZS, Butcher PA, Stokesbury MJW, Raghavan R, Gallagher AJ, Hammerschlag N, Danylchuk AJ. (2014). Angling for endangered fish: Conservation problem or conservation action? Fish and Fisheries. DOI: 10.1111/faf.12076

Gallagher, AJ, Serafy, JE, Cooke, SJ, Hammerschlag, N (2014) Physiological stress response, reflex impairment, and survival of five sympatric shark species following experimental capture and release. Marine Ecology Progress Series doi:10.3354/meps10490.

Hammerschlag N, Gallagher AJ, Carlson JK. (2013) A revised estimate of daily ration in the tiger shark (Galeocerdo cuvier) with implications for assessing ecosystem impacts of apex predators. Functional Ecology 27 (5): 1273-1274

Fallows C, Gallagher AJ, Hammerschlag N (2013) White Sharks (Carcharodon carcharias) Scavenging on Whales and Its Potential Role in Further Shaping the Ecology of an Apex Predator PLoS ONE 8(4): e60797. doi:10.1371/journal.pone.0060797.


Hammerschlag N, Luo J, Irschick DJ, Ault JS (2012) A Comparison of Spatial and Movement Patterns between Sympatric Predators: Bull Sharks (Carcharhinus leucas) and Atlantic Tarpon (Megalops atlanticus). PLoS ONE 7(9): e45958. doi:10.1371/journal.pone.0045958

Shiffman DS, Gallagher AJ, Boyle MD, Hammerschlag-Peyer CM, Hammerschlag N. 2012 (Cover). Stable Isotope Analysis as a Tool for Elasmobranch Conservation Research: A Primer for Non-Specialists. Marine and Freshwater Research, 63:635-643.

Hammerschlag N, Gallagher AJ, Wester J, Luo J, Ault JS. 2012 (Cover). Don’t bite the hand that feeds: assessing ecological impacts of provisioning ecotourism on an apex marine predator. Functional Ecology, 26(3): 567-576

Gallagher AJ, Kyne PM, Hammerschlag N. 2012. Ecological risk assessment and its application to elasmobranch conservation and management. Journal of Fish Biology, 85(5): 1727-1748

Martin RA, Hammerschlag N. (2012): Marine predator—prey contests: Ambush and speed versus vigilance and agility, Marine Biology Research, 8:1, 90-94

Mondo K, Hammerschlag N, Basile M, Pablo J, Banack SA, Mash DC. 2012. Cyanobacterial Neurotoxin β-N-Methylamino-L-alanine (BMAA) in Shark Fins, Marine Drugs, 10(2), 509-520; doi:10.3390/md10020509

Fallows C, Martin RA, Hammerschlag N. 2012. Comparisons between white shark-pinniped interactions at Seal Island (South Africa) with other sites in California (United States). In: Global Perspectives on the Biology and Life History of the Great White Shark, ed. Michael L. Domeier, CRC Press, Boca Raton, FL.

Hammerschlag N, Martin RA, Fallows C, Collier R, Lawrence R. 2012. Investigatory Behavior towards surface objects and Non-consumptive Strikes on Seabirds by White Sharks (Carcharodon carcharias) at Seal Island, South Africa (1997-2010 In: Global Perspectives on the Biology and Life History of the Great White Shark, ed. Michael L. Domeier, CRC Press, Boca Raton, FL.

Hammerschlag N, Trussell G. 2011. Beyond the Body Count: Behavioral Downgrading of Planet Earth. Science. (E-Letter, 11 November 2011)

Gallagher AJ, Jackson T, Hammerschlag N. 2011. Evidence of tiger shark (Galeocerdo cuvier) foraging on avian prey in the subtropical Atlantic. Florida Scientist, 74(4): 264–269

Hammerschlag N, Sulikowski J. 2011. Killing for Conservation: The Need for Alternatives to Lethal Sampling of Apex Predatory Sharks. Endangered Species Research 14: 135–140

Gallagher AJ, Hammerschlag N.  2011. Global Shark Currency: The Distribution, Frequency and Economic Value of Shark Eco-tourism. Current Issues in Tourism, 1–16. DOI: 10.1080/13683500.2011.585227

Hammerschlag N, Gallagher AJ, Lazarre DM. 2011. A Review of Shark Satellite Tagging Studies. Journal of Experimental Marine Biology and Ecology; 398(1-2): 1–8.

Hammerschlag N, Gallagher AJ, Lazarre DM, Slonim C. 2011. Range extension of the endangered great hammerhead shark Sphyrna mokarran in the Northwest Atlantic: Preliminary data and significance for conservation; Endangered Species Research, 13: 111–116.

Brand LE, Pablo J, Compton A, Hammerschlag N, Mash DC. 2010. Cyanobacterial Blooms and the Occurrence of the neurotoxin beta-N-methylamino-L-alanine (BMAA) in South Florida Aquatic Food Webs. Harmful Algae 9: 620–635

Hammerschlag N, Heithaus MR, Serafy JE. 2010. The influence of predation risk and food supply on nocturnal fish foraging distributions along a subtropical mangrove-seagrass ecotone. Marine Ecology Progress Series 414: 223-235

Hammerschlag N, Ovando D, Serafy, JE. 2010. Seasonal diet and feeding habits of juvenile fishes foraging along a subtropical marine ecotone. Aquatic Biology, 9:279–290.

Hammerschlag N, Morgan A, Serafy JE. 2010. Relative predation risk for fishes along a subtropical mangrove-seagrass ecotone. Marine Ecology Progress Series, 401: 259–267

Hammerschlag N, Serafy JE. 2010. Nocturnal fish utilization of a subtropical mangrove-seagrass ectone. Marine Ecology, 31:364–374

Milano GR, Hammerschlag N, Barimo J, Serafy JE. (2007) Restoring essential fish habitat in southeast Florida: mangrove and seagrass habitat design components and success monitoring. Bulletin of Marine Science 80:928-929

Martin RA, Rossmo DK, Hammerschlag N. 2009. Hunting patterns and geographic profiling of white shark predation. Journal of Zoology, 279: 111–118.

Hammerschlag N, Martin RA, Fallows C. 2006. Effects of environmental conditions on predator-prey interactions between white sharks (Carcharodon carcharias) and Cape fur seals (Arctocephalus pusillus pusillus) at Seal Island, South Africa. Environmental Biology of Fishes 76: 341–350.

Hammerschlag N. 2006. Osmoregulation in Elasmobranchs: A review for fish biologists, behaviourists and ecologists. Marine and Freshwater Behaviour and Physiology 39(3): 209–228.

Martin RA, Hammerschlag N, Collier R, Fallows C. 2005. Predatory Behaviour of White Sharks (Carcharodon carcharias) at Seal Island, South Africa. Journal of the Marine Biological Association of the UK, 85: 1121–1135.

Hammerschlag N, Fallows C. 2005. Galapagos sharks (Carcharhinus galapagensis) at the Bassas da India atoll: first record from the Mozambique Channel and possible significance as a nursery area. South African Journal of Science 101: 375–377.

Hammerschlag N. 2004. A review of osmoregulation in freshwater and marine elasmobranchs. pp. 35-41. In: R.A. Martin and D. MacKinlay (ed.) Extended Abstract in Proceedings of the American Fisheries Society, fourth International Congress on the Biology of Fish, Manaus, Brazil.


Virginia Ansaldi

After two years at Miami Dade College, I transferred into the University of Miami’s Marine Science Department where I received my bachelor's degree in Marine Affairs and Policy with a minor in Business. During my first year at UM I started my internship with the RJ Dunlap Marine Conservation Program, at that time the South Florida Student Shark Program. Since then I have been with the organization for almost 4 years and have been lucky enough to see our group grow in numbers, support, and, most importantly, research projects, data collected, and outreach. After pursuing a temporary teaching job on Catalina Island, I now return to my beloved Miami for graduate school, primarily to continue my work with RJD as Lab Manager of the program. I am continuing my education with a master’s degree in Multimedia Journalism through the University of Miami’s School of Communication and look forward to servicing the RJD Program by helping to extend its mission for years to come.

Christine Shepard

My work at the RJD Program strives to: (1) increase comprehension of and interest in RJD research and outreach; (2) increase the visibility of the RJD Program; and (3) inspire a marine conservation ethic amongst the general public. I utilize a wide array of media, including photography, video, interactive media, print media, infographics, web design, and social media, to communicate the research of Dr. Neil Hammerschlag and his students to the public in an engaging format.

Tel: 949.677.7809
Lab Website:
Personal Website:

Ph.D. Students

Austin J. Gallagher

For my PhD I am looking at the vulnerabilities of shark species to recreational fishing. I am using biological, ecological, and physiological shark data, as well as a novel inclusion of social data by measuring fisherman behavior and attitudes to rank the risks according to species. My work also includes the application of satellite telemetry to provide answers to ecological questions related to shark life histories in the subtropical Atlantic. I am fascinated by evolution and ecology, and am actively engaged educating the greater community through outreach and hands-on experience. In addition to research, I am an avid videographer and photographer and started the Beneath the Waves Film Festival to further link the research and film making communities. I received my undergraduate degree in Biology from Loyola University in Maryland, and I hold a Master’s degree from Northeastern University in Boston, MA. My PhD is through the Abess Center for Ecosystem Science and Policy, and I am a research assistant with the RJ Dunlap Marine Conservation Program..


David Shiffman

After graduating with distinction in Biology from Duke University and earning my Masters in Marine Biology from the College of Charleston, I will be working towards my Ph.D. in Ecosystem Science and Policy at the University of Miami. My research will focus on what happens to fish communities and ecosystems when shark populations decrease or are eliminated entirely. My interests include behavioral ecology, feeding and trophic relationships, conservation, stable isotope analysis, and genetics.

I also educate the public about sharks using my blogand Twitter (@WhySharksMatter), and am the Online Outreach Coordinator for the American Elasmobranch Society.

Julia Wester

During her undergraduate degree, she double majored in Psychology and Geography, which gave her the skills to approach topics from multiple perspectives in social and natural sciences. Ms. Wester completed an impressive Master’s degree at Oxford University. There she pursued specialized training in the field of environmental policy, where she received intensive, interdisciplinary education in all aspects of conservation biology, including examination of the relationship between nature and society, environmental governance, strategic conservation planning, conservation biogeography, international environmental law and social ecology. Her Master's thesis used a unique set of methodologies found in geography and psychology to determine how different groups react to "fear" versus "hope" based conservation messaging in attitudes toward biodiversity loss and potential conservation action. Her findings highlighted the socially normative aspects of conservation messaging in the developed world, the media saturation of fear based messaging, and the complex demographic interactions that determine public attitudes toward conservation. Since graduating from Oxford University, Julia has been working as a Legislative Aide to State Senator Sachs. Her work as required Julia to synthesize research in a wide range of disciplines in order to make policy recommendations, engage stakeholders and draft potential legislation.

Meaghen E. McCord

I am currently conducting research into the ecology, behaviour and management of Zambezi (bull) sharks, Carcharhinus leucas, along coastal Africa – a project partially funded by the Save Our Seas Foundation. This research will be used to inform my doctoral thesis, and is one of the primary research projects underway at the South African Shark Conservancy (SASC). My research interests include: biology and ecology of commercially exploited elasmobranch species, the role of apex predators in shaping community ecosystems, and practicable approaches to encouraging holistic fishery management strategies in developing nations. I am the founder and managing director of SASC – a non-profit research and conservation organization concerned with the sustainable utilization of marine resources, particularly elasmobranchs. I oversee the development and implementation of marine research, outreach and education programs at SASC, and work within the broader conservation and fisheries communities to encourage an ecosystem-based approach to fisheries management. I have an Honours degree in Marine Biology from Dalhousie University (Nova Scotia, Canada) and an MSc in Fisheries Science from Rhodes University (South Africa).


MS Students:

Fiona Graham

I began an internship with the RJ Dunlap Marine Conservation Program in my junior year of my undergraduate degree at the University of Miami in 2009 and have been with the program ever since. After graduating with a B.S. in Marine Biology in 2010, I shortly began a master’s degree at RSMAS in the Marine Affairs and Policy division. My concentration and interest is in marine conservation, particularly that of shark species in south Florida. More specifically, my research looks at the habitat use and movement patterns of bull, tiger, lemon and hammerhead sharks in the Florida Keys, and how that overlaps with the current marine protected area system in place. I aim to determine the extent to which current boundaries protect the species in this area and recommend opportunities for improvement.

Brittany Bartlett

In 2011 I graduated from Lehigh University with a BA in Environmental Studies and Political Science. Today, I am currently pursuing an MS in Marine Affairs and Policy at the University of Miami’s Rosentiel School of Marine and Atmospheric Science. My current research is primarily focused on protection of highly migratory species within the eastern Pacific Ocean through bycatch mitigation. Beginning in the fall I will be lucky enough to begin an internship with the RJ Dunlap Marine Conservation Program and will continue to pursue my goals with regards to ocean protection.

Stacey Assael

In 2010 I graduated from Stony Brook University with a BS in Marine Vertebrate Biology. I have since been working towards my Master’s degree in Marine Affairs and Policy at the University of Miami. Currently, my research aims to identify possible explanatory factors for long distance Tiger Shark, Galeocerdo curvier, migrations. To do this I am comparing several tracks from satellite tagged sharks to Earth’s magnetic field, sea surface temperature, salinity, surface currents, and bathymetry. Additionally, I have been working as an intern for the RJ Dunlap Marine Conservation Program for the past year.


MPS Students

Becca Shelton

I received my Bachelor of Science in Environmental Studies (Natural Resource Management and Conservation) from San Francisco State University in 2010. After taking a year off to work at, I am now pursuing a Professional Master of Science in Marine Biology through Northeastern University’s Three Seas Program. As part of the program, the graduate students participate in a research based internship and I have always dreamed about working with sharks. I am excited to be working with Dr. Neil Hammerschlag and the RJ Dunlap team. I will be working with Dr. Hammerschlag on a predator-prey experiment and we are going to test the non-consumptive effects of bonnethead sharks (Sphyrna tiburo) on blue crabs (Callinectes sapidus). These are both local species and we are going to see how the shark presence effects various types of the crabs’ behavior and physiology and what changes may occur if the sharks disappear from the environment.  I am really looking forward to my experiment and time with the RJD team.

Jennah Caster

I am a passionate traveler, diver, photographer, and marine conservation enthusiast, with a love for sharks. I earned a Bachelor of Science degree in Environmental Studies from the University of Southern California, with a minor in Digital Media-Based Imaging. Now I am working towards a Masters degree in Marine Affairs and Policy from the University of Miami’s Rosenstiel School of Marine and Atmospheric Science. For my MPS degree, I am completing a six-month internship with the non-profit organization Shark Savers. My primary focus is to promote education, outreach, and advocacy for shark conservation. I will do this through social and digital media, as well as through SharksCount, a citizen science initiative for sharks. During this time, I will also be contributing to the R.J. Dunlap Marine Conservation Program to further shark research and the education of citizens through hands-on learning experiences. Dr. Hammerschlag and this stellar team of graduate students helped inspire me to focus my research and future on sharks.

Past students

Christine Shepard

I am an undergraduate student in the Ecosystem Science & Policy Program and Communications. My passions have always been torn between being outdoors, connecting with nature, and utilizing my creative mind to make the world a little bit more beautiful. When I began my degree at the University of Miami, I realized I need not be torn any longer, only busy. I am currently finishing up my last semester of a dual degree in Ecosystems Science and Policy and in Electronic Media.

Being a fish at heart myself, I was naturally drawn to the Dunlap Program at its inception in January. Both Dr. Hammerschlag and I realized we had much to gain from working together. I have become a Media Projects Intern casually over the summer, and will continue my work with even more gusto in the Fall. My primary focus is on improving the online satellite tracking of the sharks, rewriting and redesigning some of the educational pages on the site, and hopefully adding more features, such as webinars, videos, and possibly a kid's zone."

Rachael Kraemer

I received my B.S. from Florida Southern College in 2008 with a major in biology emphasizing on marine and environmental sciences.  I am currently pursuing my master’s degree in marine biology through Northeastern University’s Three Seas program.  I am completing the internship portion of the program with RSMAS and the RJ Dunlap program as a research intern.  I am interested in combining marine conservation efforts with outreach and education, something the RJ Dunlap program does very well.  My current research focuses on predator-prey interactions among sharks of different size classes.  Using baited underwater video, we are also examining how the presence of sharks influences the structure and behavior of surrounding fish communities.

Virginia Ansaldi

After two years at Miami Dade College, I transferred into the University of Miami’s Marine Science Department where I received my bachelor's degree in Marine Affairs and Policy with a minor in Business. During my first year at UM I started my internship with the RJ Dunlap Marine Conservation Program, at that time the South Florida Student Shark Program. Since then I have been with the organization for almost 4 years and have been lucky enough to see our group grow in numbers, support, and, most importantly, research sites and data collected. After pursuing a temporary teaching job on Catalina Island, I now return to my beloved Miami for graduate school, primarily to continue my work with RJD. I will be continuing my education with a master’s degree in TV Broadcasting and New Media through the University of Miami’s School of Communication and look forward to servicing the RJD Program helping to extend its mission for years to come.

Jordan Creed

Conservation has always been my story. I am taking my M.S. in Marine Conservation from RSMAS, and applying it to coastal wetland conservation in Virginia Beach, Virginia. Currently I am working as a Conservation Technician for the Virginia Department of Conservation and Recreation. I spend every day in tidal marshlands, ponds, rivers, and forests looking for threatened and endangered wildlife species, and removing invasive vegetation and animals.

Working with Dr. Hammerschlag gave me the experience and insight I needed to apply the specialized skills I learned while studying at the University of Miami to broad conservation practices in many different environments. I aspire to continue working in the Hampton Roads Region, helping to protect this area's natural resources, so they can be enjoyed by future generations.

Piper Wallingford

My research focuses on how marine predators and environmental conditions affect fish behavior, specifically anti-predator behaviors in reef and mangrove fishes. Understanding predator-prey relationships is important for determining long-term conservation strategies for reef and mangrove ecosystems, especially in the face of climate change and global declines of predator populations.

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