Neil Hammerschlag

Neil Hammerschlag

Research Assistant Professor , Department of Marine Ecosystems and Society

University of Miami
4600 Rickenbacker Causeway
Miami, FL 33149

East "Grovesnor 212"

Tel: 305.421.4356

Lab Website


Google Scholar Profile

My research centers broadly on the behavioral ecology and conservation biology of marine predators. My current and future research has four core themes: (1) understanding how predator-prey interactions impact individual traits, community structure and ecosystem processes through trophic cascades; (2) evaluating the ecological and evolutionary implications of variation in physiological and morphological adaptations on the movement ecology of marine predators; (3) examining how coastal urbanization affects the behavior, ecology and fitness of highly mobile fishes; and (4) testing theories of individual specialization in fish diet and migration across multiple trophic levels. My research philosophy relies on two fundamental approaches. First, I put a strong emphasis on natural history, spending time observing wildlife as a starting point for developing project ideas and testable hypotheses. Second, I apply ecological and evolutionary theory as frameworks for empirical measurements to address and advance my fields of research. My work is highly collaborative and cross-disciplinary among different research groups and institutions. Further, it employs a variety of low- and high-tech tools including visual surveys, stable isotope analysis, biotelemetry, ultrasonography, diet analysis, underwater video, triglyceride assays and blood hormone analysis. I have research projects underway in Florida, Bahamas, South Africa and Australia.

I currently direct the RJ Dunlap Marine Conservation Program (RJD) at the University of Miami. The mission of RJD is to advance ocean conservation and scientific literacy by conducting cutting edge scientific research and providing innovative and meaningful outreach opportunities for students through exhilarating hands-on research and virtual learning experiences in marine biology. Opportunities are especially made available for students from land-locked communities and under-served populations in the sciences. Focusing primarily on the study and conservation of sharks, the Program’s full-immersion approach allows students to actively grow as future scientists. To impact an even larger audience from across the globe, we continue to use a variety of online education tools, including virtual expeditions, webinars, pod-casts, blogs, online curricula and social media.

Tiger shark migration in the Northwest Atlantic revealed through satellite tagging. Modified from Hammerschlag et al. (2012), Functional Ecology, 26(3): 567-576
Tiger shark migration in the Northwest Atlantic revealed through satellite tagging. Modified from Hammerschlag et al. (2012), Functional Ecology, 26(3): 567-576

Nguyen VM, Haddaway NR, Gutowsky LFG, Wilson ADM, Gallagher AJ, Donaldson MR, Hammerschlag N, Cooke SJ. (2015) How Long Is Too Long in Contemporary Peer Review? Perspectives from Authors Publishing in Conservation Biology Journals. PLoS ONE 10(8): e0132557. doi:10.1371/journal.pone.0132557

Gallagher AJ, Hammerschlag N, Cooke SJ, Costa DP, Irschick DJ (2015).One size does not always fit all: a reply to Stroud and Feeley. Trends in Ecology and Evolution.DOI:10.1016/j.tree.2015.03.011

Hammerschlag N, Broderick AC, Coker JW, Coyne MS, Dodd M, Frick MG, Godfrey MH, Godley BJ, Griffin DB, Hartog K, Murphy SR, Murphy TM, Nelson ER, Williams KL, Witt MJ, Hawkes LA (2015). Evaluating the landscape of fear between apex predatory sharks and mobile sea turtles across a large dynamic seascape. Ecology, 96(8): 2117-2126


Gallagher AJ, Vianna GMS, Papastamatiou YP, Macdonald C, Guttridge TL, Hammerschlag N. (2015) Biological effects, conservation potential, and research priorities of shark diving tourism. Biological Conservation, 184: 365-379

Fallows C, Benoit HP, Hammerschlag N. (2015). Intraguild predation and partial consumption of blue sharks (Prionace glauca) by Cape fur seals (Arctocephalus pusillus pusillus). African Journal of Marine Science, DOI: 10.2989/1814232X.2015.1013058


Gallagher AJ, Hammerschlag N, Cooke SJ, Costa DP, Irschick DJ (2015). Evolutionary theory as a tool for predicting extinction risk. Trends in Ecology and Evolution, 30(2): 61-65

Hammerschlag N, Cooke SJ, Gallagher AJ, Godley BJ. (2013). Considering the fate of electronic tags: user responsibility and interactions when encountering tagged marine animals; Methods in Ecology and Evolution. doi: 10.1111/2041-210X.12248


Shiffman DS, Hammerschlag N (2014) An assessment of the scale, practices, and conservation implications of Florida’s charterboat-based recreational shark fisheryFisheries,39(9): 395-407

Irschick, DJ, Hammerschlag N, (2014). Morphological scaling of body form in four shark species differing in ecology and life-history. Biological Journal of the Linnean Society

Shiffman DS, Gallagher AJ, Wester J, Macdonald CC, Thaler AD, Cooke SJ, Hammerschlag N. (2015). A letter of clarification from the authors of 'Trophy fishing for species threatened with extinction'. Marine Policy 53, 213-214.

Shiffman DS, Gallagher AJ, Wester, Macdonald C, Thaler AD, Cooke SJ, Hammerschlag N (2014). Trophy fishing for species threatened with extinction: a way forward building on a history of conservation. Marine Policy. 50: 318-322

Gallagher AJ, Orbesen ES, Hammerschlag N, Serafy JE (2014). Vulnerability of oceanic sharks as pelagic longline bycatch. Global Ecology and Conservation. DOI: 10.1016/j.gecco.2014.06.003

Rumbold D, Wasno B, Hammerschlag N, Volety A. (2014). Mercury accumulation in sharks from the coastal waters of Southwest Florida. Archives of Environmental Contamination and Toxicology; DOI 10.1007/s00244-014-0050-6

Irschick DI., Hammerschlag N. (2014). A new metric for measuring condition in large predatory sharks; Journal of Fish Biology; DOI: 10.1111/jfb.12484

Gallagher, AJ, Wagner, DN, Irschick, DJ, Hammerschlag N. (2014). Body condition predicts energy stores in apex predatory sharks. Conservation Physiology; 2. DOI: 10.1093/conphys/cou022

Gallagher AJ, Hammerschlag N, Shiffman DS, Giery ST (2014) Evolved for extinction: the cost and conservation implications of extreme specialization in hammerhead sharks. BioScience doi:10.1093/biosci/biu071

Gallagher AJ, Romeiro J, Canabal D, Canabal V, Hammerschlag N (2014). Novel social behaviors in a threatened apex marine predator, the oceanic whitetip shark Carcharhinus longimanus. Ethology Ecology & Evolution;

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.

Prospective students

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Lab Members & Interns

Current Staff & Graduate Students

Christian Pankow

After receiving my B.S. in Marine Biology at Eckerd College, I worked at the Bimini Biological Field Station (Sharklab) in the Bahamas for 3 years where I ultimately became Lab Manager. After traveling abroad for a year, I came back to the Bahamas to pilot a live-aboard eco-tourism boat for two years before heading back to the states to pursue my Master's at Coastal Carolina University in South Carolina. I am currently finalizing my Master's work which deals with feeding ecology and seasonality of estuarine sharks and am acting Lab Manager for the Hammerschlag Lab / University of Miami RJ Dunlap Marine Conservation Program.


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 blog and Twitter (@WhySharksMatter), and am the Online Outreach Coordinator for the American Elasmobranch Society.

MS Students:

Robbie Roemer

I am originally from Baltimore, Maryland and have graduated from Coastal Carolina University with a B.S. in Marine Science. Since then, I have had the privilege to work for the shark research and conservation program at the Cape Eleuthera Institute as well as the Highly Migratory Species Division of the National Oceanographic and Atmospheric Administration. I am currently pursuing a Masters of Science in Marine Affairs and Policy here at the University of Miami. My research interests are primarily focused on spatial ecology of marine predators, predator prey dynamics of sharks, and growth rate analysis of juvenile sharks in response to prey selection. My past research experience has focused on fishery population dynamics, predator prey dynamics, stress physiology of sharks, and mark recapture studies.


Hannah Calich

I received a Bachelor of Science Combined Honours Co-op degree in Marine Biology and Oceanography from Dalhousie University in 2012. In 2013, I moved to Miami and began working towards a Masters degree in Marine Affairs and Policy at the University of Miami. My research interests are primarily focused around the behavioral ecology and conservation of marine organisms. Specifically, I am currently researching how biological and physical factors influence shark abundance and distribution in South Florida.


Jake Jerome

Originating from the Midwest, I received my Bachelor of Science degree in biological sciences with an emphasis in zoology from Western Illinois University in 2013. I then decided to make the move to Miami and have been interning with the RJ Dunlap Marine Conservation Program where my love for the ocean and elasmobranch conservation has only increased. I am currently pursuing my Master’s degree in Marine Affairs and Policy at the University of Miami. My research interests are focused on marine conservation with an emphasis on sharks and their responses to fishing pressure. For my Master’s thesis, I will be examining the molecular differences that various species of sharks exhibit in response to fishing.

Patrick Goebel

In 2012 I graduated from Mercyhurst University with a Bachelor of Science in Biology and a minor in Business Administration. I am currently pursing my Masters degree in Marine Biology at Nova Southeastern University. I am currently co-advised by Dr. David Kerstetter (NSU) and Dr. Neil Hammerschlag (UM). My research interests are behavioral ecology, predator/prey interactions and conservation. My current research primarily focuses on understanding some of the important ecological patterns of predators in an inshore tropical estuary.


Alison Enchelmaier




In 2013, I graduated from Wheaton College in Massachusetts, Phi Beta Kappa, with a BA in Biology. Currently, I am pursuing my Master’s degree in Marine Affairs and Policy at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science. My current research is focused on the non-consumptive effects of predatory fish presence and absence on prey behavior and morphology. In addition to my research I have been working as an intern for the RJ Dunlap Marine Conservation Program.

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