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.
Tiger shark migration in the Northwest Atlantic revealed through satellite tagging. Modified from Hammerschlag et al. (2012), Functional Ecology, 26(3): 567-576
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. (In Press). A new metric for measuring condition in large predatory sharks; Journal of Fish Biology
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; http://dx.doi.org/10.1080/03949370.2014.896831
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
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.
Lab Members & Interns
Current Staff & Graduate Students
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.
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..
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.
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.
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.
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.
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.