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 three 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; and (3) examining how coastal urbanization affects the behavior, ecology and fitness of highly mobile fishes. 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 Predator Ecology Lab and Shark Research & Conservation Program (SRC) at the University of Miami. The SRC conducts science centered broadly on the ecology, movement and conservation of sharks. A core component of our work is to foster scientific literacy and environmental ethic in youth and the public by providing exciting hands-on field research experiences in marine conservation biology. Opportunities are especially made available for under-served populations in the sciences. To impact a global, we employ online outreach tools, including webinars, curricula, videos, blogs, and social media. Focusing primarily on the study and conservation of sharks, we employ a full-immersion educational approach that allows students to actively grow as future scientists.

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

Fallows C, Fallows M, Hammerschlag N. (2016) Effects of lunar phase on predator-prey interactions between white shark (Carcharodon carcharias) and Cape fur seals (Arctocephalus pusillus pusillus). Environmental Biology of Fishes; doi:10.1007/s10641-016-0515-8

Hammerschlag N., Davis DA, Mondo K, Seely MS, Murch SJ, Glover WB, Divoll T, Evers DC, Mash DC. (2016) Cyanobacterial Neurotoxin BMAA and Mercury in Sharks. Toxins 2016, 8, 238.

Hammerschlag N., Bell I, Fitzpatrick I, Gallagher AJ, Hawkes LA, Meekan MG, Stevens JD, Thums M, Witt MJ, Barnett A. (2016). Behavioral evidence suggests facultative scavenging by a marine apex predator during a food pulse. Behavioral Ecology and Sociobiology. doi:10.1007/s00265-016-2183-2

Roemer RP, Gallagher AJ, Hammerschlag N. (2016). Shallow water tidal flat use and associated specialized foraging behavior of the great hammerhead shark (Sphyrna mokarran). Marine and Freshwater Behaviour and Physiology, doi: 10.1080/10236244.2016.1168089

Cooke SJ, Nguyen VM, Wilson AD, Donaldson MR, Gallagher A, Hammerschlag N, Haddaway NR. (2016) The need for speed in a crisis discipline: perspectives on peer review duration and implications for conservation science. Endangered Species Research 30: 11-19

Shiffman, D.S. and Hammerschlag N. (2016). Shark Conservation and Management Policy: A Review and Primer for Non-Specialists. Animal Conservation

Sulikowski J, Wheeler CR, Gallagher AJ, Prohaska BK, Langan JA, Hammerschlag N. (2016). Seasonal and life-stage variation in the reproductive ecology of a marine apex predator, the tiger shark Galeocerdo cuvier, at a protected female dominated site. Aquatic Biology, 24: 175-184

Shiffman DS, Hammerschlag N (2016). Preferred conservation policies of shark researchers. Conservation Biology.

Fu A, Hammerschlag N, Lauder G, Wilga C, Kuo C, Irschick DJ. (2016) Ontogeny of head and caudal fin shape of an apex marine predator: the tiger shark (Galeocerdo cuvier). Journal of Morphology.

Graham F, Rynne P, Estevanez M, Luo J, Ault JS, Hammerschlag N (2016), Use of marine protected areas and exclusive economic zones in the subtropical western North Atlantic Ocean by large highly mobile sharks. Diversity and Distributions. doi:10.1111/ddi.12425

Queiroz N, Humphries N.E., Mucientes G., Hammerschlag N, Lima F.P, Scales K.L, Miller P.I., Sousa L.L., Seabra R., Sims D.W. (2016). Ocean-wide tracking of pelagic sharks reveals extent of overlap with longline fishing hotspots. Proceedings of the National Academy of Sciences; doi: 10.1073/pnas.1510090113

Creel S, Becker M, Christianson D, Dröge E, Hammerschlag N, Haward MW, Karanth U, Loveridge A, Macdonald DW, Wigganson M, M'soka J, Murray D, Rosenblatt E, Schuette P. (2015) Questionable policy for large carnivore hunting. Science, 350(6267): 1473-1475

Gallagher AJ, Cooke S, Hammerschlag N. (2015) Risk perceptions and conservation ethic among recreational anglers targeting threatened sharks in the subtropical Atlantic. Endangered Species Research, 29, 81-93

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 his B.S. in Marine Biology at Eckerd College, Christian worked at the Bimini Biological Field Station (Sharklab) in the Bahamas for 3 years where he ultimately became Lab Manager. After traveling abroad for a year, Christian came back to the Bahamas to pilot a live-aboard eco-tourism boat for two years before heading back to the states to pursue his Master's at Coastal Carolina University in South Carolina. Christian is currently finalizing his Master's work which deals with feeding ecology and seasonality of estuarine sharks. In Miami, Christian served as Lab Manager for the Hammerschlag Lab / Shark Research & Conservation Program at the University of Miami and is currently the Director of Field Research with The Field School.


David Shiffman

After graduating with distinction in Biology from Duke University and earning his Masters in Marine Biology from the College of Charleston, David is working towards his Ph.D. in Ecosystem Science and Policy at the University of Miami. David's interdisciplinary project is focused on understanding the ecosystem role that sharks play in coastal south Florida, as well as what different groups of stakeholders (anglers, scientists, and conservation activists) believe that ecosystem role to be. He uses a combination of stable isotope analysis, surveys, and content and discourse analysis of websites and social media postings to gather this data.


Leila AtallahBenson

Leila received her B. S. in Marine Science from Northeastern University in 2014. While attending Northeastern, she spent time in Panama, studying marine systems, and Turks and Caicos, working for the Department of Environment and Maritime Affairs. The year following graduation Leila received her PADI Divemasters in Honduras, and spent 5 months interning at the Bimini Biological Field Station in the Bahamas. She joined the Shark Research and Conservation Program at the University of Miami Rosenstiel School of Marine and Atmospheric Science as a Master's student studying Shark Immunity.



Hannah Calich

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



Alison Enchelmaier

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



Pat Goebel

In 2012 Pat graduated from Mercyhurst University with a Bachelor of Science in Biology and a minor in Business Adminis tration. He is currently pursuing his Master’s degree in Marine Biology at Nova Southeastern University while being co-advised by Dr. David Kerstetter (NSU) and Dr. Neil Hammerschlag (UM). Pat’s research interests are behavioral ecology, predator/prey interactions and conservation with his current research primarily focusing on understanding some of the important ecological patterns of predators in an inshore tropical estuary.



Jake Jerome

Originating from the Midwest, Jake received his Bachelor of Science degree in biological sciences with an emphasis in zoology from Western Illinois University in 2013. He is currently pursuing his Master’s degree in Marine Affairs and Policy here at RSMAS. Jake’s research interests are focused on marine conservation with an emphasis on sharks and their responses to fishing pressure. More specifically, he is currently researching how varying species of sharks differ in their behavioral and physiological responses to stressors such as fishing.



Emily Rose Nelson

Emily Rose Nelson has been fascinated with the ocean for as long as she can remember. This passion forced her out of her landlocked hometown of Chicago and to the University of Miami where she received her Bachelors degree in Marine and Atmospheric Science. Currently, she is a graduate student at the Rosenstiel School of Marine and Atmospheric Science studying Marine Affairs and Policy. It was on a trip with Jim Abernethy and Dr. Neil Hammerschlag in 2012 where she truly fell in love with sharks. Ever since, she has been working with the Shark Research and Conservation Program ( Currently she is the lab’s Shark Satellite Tracking Coordinator. Emily has a broad range of research interests including (1)spatial ecology of apex predatory sharks; (2)evolutionary adaptations using morphological differences within and among species; (3)direct and indirect effects of predator-prey interactions; and (4)shark – human interactions.



Robbie Roemer

Robbie graduated from Coastal Carolina University with a B.S. in Marine Science. Since then, he has worked 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. Robbie is currently pursuing a Masters of Science in Marine Affairs and Policy here at the University of Miami. His research is currently focusing on the localized movements of urbanized shark populations and conducting stress physiology assessments on both urbanized sharks and finfish species. His other interests include predator-prey dynamics and non-invasive growth rate analysis.


Rachel Skubel

Rachel is from Ontario, Canada, where she graduated with an M.Sc. in Environmental Science from McMaster University, and a B.Sc. from the University of Western Ontario. Her current research interests revolve around how top predators such as sharks will be impacted by environmental change, as well as the human societies that rely on them - directly or indirectly.






Julia Whidden

Julia completed her Masters in Biology with a focus on marine conservation from Acadia University in Nova Scotia, Canada, in 2015. Her project evaluated population demographics and species identification of two at-risk species of skate in the inner Bay of Fundy. She joins the lab for the year as a Fulbright Student, and will be assisting on a variety of lab projects. Specifically, Julia will be investigating morphological differences in the distribution of the ampullae of Lorenzini of several species of sharks in comparison to their feeding strategies.



Natascha Wosnick

Natascha is from Curitiba, Brazil and she graduated from Federal University of Paraná with a Bachelor of Science in Biology 2009, and received her Masters degree in Physiology with specialization in Animal Physiology in 2012. Currently, she is a PhD student in Zoology at the Federal University of Paraná, working on the ecophysiology and behavioral physiology of sharks and rays, with emphasis on how these animals respond to changes in their environment, such as salinity and temperature. She will be studying with the Shark Research and Conservation lab until May of 2016 under Dr. Hammerschlag’s guidance on a project involving the thermal signature of sharks.


Stephen Cain

Stephen holds a Bachelor of Arts in English from The University of Iowa. Prior to pursuing marine science, he worked in the private sector, where he developed a flair for strategic communications and administration in the diverse fields of information technology, hospitality, and higher education. At the UM Rosenstiel School his Masters research focused on environmental psychology and environmental education. As an intern for SRC he advanced the lab’s community outreach by speaking with hundreds of high school students and by implementing surveys to measure the efficacy of SRC’s educational programs.

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