Rosenstiel School

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

Skubel RA, Kirtman BP, Fallows C, Hammerschlag N (2018) Patterns of long-term climate variability and predation rates by a marine apex predator, the white shark Carcharodon carcharias. Marine Ecology Progress Series 587:129-139.

Hammerschlag N, Barley SC, Irschick DJ, Meeuwig JJ, Nelson ER, Meekan MG (2018) Predator declines and morphological changes in prey: evidence from coral reefs depleted of sharks. Marine Ecology Progress Series 586:127-139.

Klimley AP, Flagg M, Hammerschlag N, Hearn A. (2017). The value of using measurements of geomagnetic field in addition to irradiance and sea surface temperature to estimate geolocations of tagged aquatic animals. Animal Biotelemetry; 2;5(1):19.

Hammerschlag N, Meÿer M, Seakamela S M, Kirkman S, Fallows C, Creel S. (2017) Physiological stress responses to natural variation in predation risk: evidence from white sharks and seals. Ecology, 98: 3199-3210.

Jerome JM, Gallagher AJ, Cooke SJ, Hammerschlag N. (2017). Integrating reflexes with physiological measures to evaluate coastal shark stress response to capture. ICES Journal of Marine Science; fsx191,

Macdonald C, Gallagher AJ, Barnett A, Brunnschweiler J, Shiffman DS, Hammerschlag N. (2017). Conservation potential of apex predator tourism. Biological Conservation; 215: 132-141

Acuña-Marrero D, Smith ANH, Hammerschlag N, Hearn A, Anderson MJ, Calich H, et al. (2017) Residency and movement patterns of an apex predatory shark (Galeocerdo cuvier) at the Galapagos Marine Reserve. PLoS ONE 12(8): e0183669.

Irschick DJ, Fu A, Lauder G, Wilga C, Kuo C-Y, Hammerschlag N. (2017) A comparative morphological analysis of body and fin shape for eight shark speciesl Biological Journal of the Linnean Society, blx088,

Shiffman DS, Macdonald C, Ganz HY, Hammerschlag N. (2017). Fishing practices and representations of shark conservation issues among users of a land-based shark angling online forum. Fisheries Research; 196: 13-26.

Hammerschlag N, Gutowsky LFG, Gallagher AJ, Matich P, Cooke SJ. (2017). Diel habitat use patterns of a marine apex predator (tiger shark, Galeocerdo cuvier) at a high use area exposed to dive tourism. Journal of Experimental Marine Biology and Ecology, 495: 24-34.

Hammerschlag N, Gallagher AJ. (2017). Extinction Risk and Conservation of the Earth’s National Animal Symbols. BioScience; 67(8): 744-749.


Gallagher AJ, Shiffman DS, Byrnes EE, Hammerschlag-Peyer CM, Hammerschlag N. (2017). Patterns of resource use and isotopic niche overlap among three species of sharks occurring within a protected subtropical estuary. Aquatic Ecology; 1-14.

Cooke SJ, Gallagher AJ, Sopinka NM, Nguyen VM, Skubel RA, Hammerschlag N, Boon S, Young N, and Danylchuk AJ (2017). Considerations for effective science communication. FACETS 2: 233-248. doi: []10.1139/facets-2016-0055

Gallagher AJ, Skubel RA, Pethybridge HR, Hammerschlag N. (2017). Energy metabolism in mobile, wild-sampled sharks inferred by plasma lipids. Conserv Physiol; 5 (1): cox002. doi: 10.1093/conphys/cox002

Matulik AG, Kerstetter DW, Hammerschlag N, Divoll T, Hammerschmidt CR, Evers DC. (2017). Bioaccumulation and biomagnification of mercury and methylmercury in four sympatric coastal sharks in a protected subtropical lagoon. Marine Pollution Bulletin; 116(1): 357-364.

Hammerschlag N, Meyer C, Grace M, Kessel S, Sutton T, Harvey E, Paris C, Kerstetter D, Cooke SJ. (2017). Shining a Light on Fish at Night: an overview of patterns and processes operating in fish and fisheries at night and in the perpetual darkness of deep and polar seas. Bulletin of Marine Science; 93(2): 253-284

Hammerschlag N, Skubel R, Calich H, Nelson ER, Shiffman DS, Wester J, Macdonald C, Cain S, Jennings L, Enchaelmaier A, Gallagher AJ. (2017). Nocturnal and crepuscular behavior in elasmobranchs: a review of movement, habitat use, foraging, and reproduction in the dark. Bulletin of Marine Science; 93(2): 355-374.

Rangel BdS, Wosnick N, Hammerschlag N, Ciena AP, Kfoury Junior JR. Rici REG (2016). A preliminary investigation into the morphology of oral papillae and denticles of blue sharks (Prionace glauca) with inferences about its functional significance across life stages. Journal of Anatomy; 230(3): 389-397

Gallagher AJ, Hammerschlag N, Danylchuk AJ, Cooke SJ. (2016). Shark recreational fisheries: Status, challenges, and research needs. Ambio; 1-14.

Gallagher AJ, Staaterman ER, Cooke SJ, Hammerschlag N. (2016). Behavioral responses to fisheries capture among various shark species reveal mechanisms of species-specific sensitivity. Canadian Journal of Fisheries and Aquatic Sciences; 74(1): 1-7.

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; 99(11): 805-812.

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; 70(1): 1777-1788.

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; 49(4): 235-249.

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; 19(5): 401-412.

Fu A, Lauder G, Wilga C, Kuo C, Hammerschlag N, Irschick DJ. (2016). Ontogeny of head and caudal fin shape of an apex marine predator: the tiger shark (Galeocerdo cuvier). Journal of Morphology; 277(5): 556-564.

Shiffman, DS and Hammerschlag, N. (2016). Preferred conservation policies of shark researchers. Conservation Biology; 30(4): 805-815.

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; 22(5): 534-546.

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; 113(6): 1582-1587.

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

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 SJ, Hammerschlag N. (2015). Risk perceptions and conservation ethic among recreational anglers targeting threatened sharks in the subtropical Atlantic. Endangered Species Research, 29(1): 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.

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; 30(6): 297-298.

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

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

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; 37(1): 125-128.

D.S. Shiffman, A.J. Gallagher, J. Wester C.C. Macdonald, A.D. Thaler, S.J. Cooke, and N. Hammerschlag. (2015). A letter of clarification from the authors of “trophy fishing for species threatened with extinction”. Marine Policy 53, 213-214.

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; 11(5): 1147-1153.

Shiffman DS, Hammerschlag N. (2014). An assessment of the scale, practices, and conservation implications of Florida’s charterboat-based recreational shark fishery. Fisheries, 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; 114(1): 126-135.

Shiffman, D.S, 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). Survival and vulnerability of pelagic shark species to pelagic longline bycatch. Global Ecology and Conservation; 1: 50-59.

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; 67(3): 402-412.

Irschick DI., Hammerschlag N. (2014). A new metric for measuring condition in large predatory sharks. Journal of Fish Biology; 85(3), 917-926.

Gallagher, AJ, Wagner, DN, Irschick, DJ, Hammerschlag, N. (2014). Body condition predicts energy stores in apex predatory sharks. Conservation Physiology; 2 (1): 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; 64(7): 619-624.

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; 17(1): 249-265.

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; 26(4), 413-417.

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; 494: 207-218

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). 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. 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.

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

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.

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

Interested in joining my lab as a graduate student? Please CLICK HERE to see my note to prospective students.

Interested in an applying for an internship or as a student in my lab, please CLICK HERE to see how you can get involved.

Current Lab Staff & Graduate Students

Stephen Cain – Assistant Director & Lab Manager
Rachel Skubel – PhD Student
Emily Nelson – MS Student
Mitchell Rider – MS Student
Shannon Moorhead – MS Student
Leila AtallahBenson – MS Student
Robbie Roemer – MS Student
Elana Rusnak – MS Student
Andy Fragola – MPS Student
David Lestino – MPS Student

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