Research

A central question in biology is how interactions between organisms and their environment shape genetic diversity and ecological resilience in the face of both climate and fishing pressure. Determining how animals adapt to changing conditions on both a genetic and behavioral level is vital to understanding the processes that drive species’ persistence, especially in large migratory organisms that grow and reproduce slowly, such as elasmobranchs (sharks, skates, and rays). Sharks are also keystone predators in most marine ecosystems whose loss can cause cascading extinctions with catastrophic effects on vulnerable habitats, so understanding their ecology and behavior is crucial for effective ocean conservation.

Research in the Daly-Engel Lab integrates molecular techniques with other data including field-based ecological sampling and telemetry to understand the causes and mechanisms of environmental adaptation and habitat use. Work in our lab has helped advance the idea that both male and female sharks genetically benefit from re-mating during a single breeding season, which helped push forth a new paradigm in our understanding of reproductive resource allocation. More recently, we have shown that both large and small coastal sharks are more movement-constrained than previously thought and that elasmobranchs in the deep sea are subject to selective pressure leading to diversification on a similar scale to shallow-water species. Other research areas include cryptic speciation, female mate choice, using environmental DNA tools to estimate ecosystem health, and inquiry-based science education.

Selected current projects: 

  • Identifying genetic relatedness among white sharks (Carcharodon carcharias) in Pacific Baja, California
  • Using genetics to discover cryptic diversity in sharks, especially sharpnose sharks (genus Rhizoprionodon) and deep-water dogfish sharks (genus Squalus)
  • Impact of climate change on bull shark (Carcharhinus leucas) nursery habitat use 
  • Physical and reproductive dispersal patterns in tiger sharks (Galeocerdo cuvier) in the West Atlantic
  • Using MHC immune genes to determine mechanisms for shark environmental adaptability, phylogenetics, and sexual selection

Publications

Helen K. Weber  Christian M. Jones  Matthew J. Ajemian  Michael P. McCallister  Brent L. Winner  Gregg R. Poulakis  Dana M. Bethea  Lisa D. Hollensead  Daniel Zapf  John D. Swenson  Jill M. Hendon  Toby S. Daly‐Engel  Nicole M. Phillips al(2020). “Genetic Evidence Supports a Range Extension for the Brazilian Cownose Ray Rhinoptera Brasiliensis in the Western North Atlantic.” Journal of Fish Biology, vol. 98, no. 2, 2020, pp. 577–582., https://doi:10.1111/jfb.14582.

Eble, J.A., T.S. Daly-Engel, J.D. DiBattista, A. Koziol, and M.R. Gaither (2020). Chapter 1. Marine Environmental DNA: Approaches, Applications, and Opportunities. In: Advances in Marine Biology 85: 1-23: https://pubmed.ncbi.nlm.nih.gov/32600544/

Shiffman, D., M. Ajemian, J. Carrier, T.S. Daly-Engel, M. Davis*, N. Dulvy, R.D. Grubbs, N.A. Hinojosa, J. Imhoff, M. Kolmann, C. Nash*, M. Paig-Tran, E.E. Peele, R. Skubel, B. Wetherbee, L. Whitenack, and J. Wyffels (2020). Trends in Chondrichthyan research: An analysis of three decades of conference abstracts. Copeia 108(1), 122-131: https://doi.org/10.1643/OT-19-179R 

Daly-Engel, T.S., I. Baremore, R.D. Grubbs, S. Gulak, R.T. Graham, and M. Enzenauer (2018) Resurrection of the sixgill shark Hexanchus vitulus Springer &Waller, 1969 (Hexanchiformes, Hexanchidae), with comments on its distribution in the northwest Atlantic Ocean. Marine Biodiversity: https://doi.org/10.1007/s12526-018-0849-x

Larson, S., T.S. Daly-Engel, and N. Phillips (2017) Ch. 3: Review of Current Conservation Genetic Analyses of Northeast Pacific Sharks. In Advances in Marine Biology: Northeast Pacific Shark Biology, Research and Conservation. Eds: S. Larson and D. Lowry. Vol. 77, Oxford: Academic Press, pp. 79-110: https://www.ncbi.nlm.nih.gov/pubmed/28882215

Selkoe, K.A., E.A. Treml, J.L.K. Wren, O. Gaggiotti, M. Donovan, K. Andrews, I. Baums, M.A. Bernal, C. Bird, H. Bolick, B. Bowen, R. Coleman, G.T. Concepcion, M.T. Craig, T.S. Daly-Engel, J.D. DiBattista, J. Eble, I. Fernandez-Silva, E. Franklin, A. Friedlander, M.R. Gaither, J. Gove, M. Iacchei, Y. Jia, M.A.J. Rivera, L.A. Rocha, J. Reece, D. Skillings, S. Santos, Z. Szabo, M. Timmers, L. Wedding, G.J. Williams, N. Whitney, and R.J. Toonen (2016) Community genetics of Hawaiian reefs reflect habitat, history, thermal stress and ecology. Proceedings of the Royal Society of London B 283: 20160354 https://royalsocietypublishing.org/doi/full/10.1098/rspb.2016.0354

Daly-Engel, T.S., R.L. Smith, D.S. Finn, M.E. Knoderbane, I.C. Phillipsen, and D.A. Lytle (2012a) 17 novel polymorphic microsatellite markers for the giant water bug, Abedus herberti (Belostomatidae). Conservation Genetics Resources 4: 979-981 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3784353/

Daly-Engel, T.S., K.M. Duncan, K.N. Holland, J.P. Coffey, H.A. Nance, R.J. Toonen, and B.W. Bowen (2012b) Global phylogeography with mixed-marker analysis reveals male-mediated dispersal in the endangered scalloped hammerhead shark (Sphyrna lewini). PLoS ONE 7(1): e29986 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6413943/

Fitzpatrick, J.L., R.M. Kempster, T.S. Daly-Engel, S.P. Collin, and J.P. Evans (2012) Assessing the potential for postcopulatory sexual selection in elasmobranchs. The Journal of Fish Biology's 2012 special issue, The Current Status of Elasmobranchs: Biology, Fisheries and Conservation. DOI: 10.1111/j.1095-8649.2012.03256.x https://onlinelibrary.wiley.com/doi/full/10.1111/j.1095-8649.2012.03256.x

Daly-Engel, T.S., J.E. Randall, and B.W. Bowen (2012c) Is the Great Barracuda (Sphyraena barracuda) a reef fish or a pelagic fish? The phylogeographic perspective. Marine Biology 159: 975-985 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3784357/

Toonen, R.J., K.R. Andrews, I.B. Baums, C.E. Bird, G.T. Concepcion, T.S. Daly-Engel, J.A. Eble, A. Faucci, M.R. Gaither, M. Iacchei, J.B. Puritz, J.K. Schultz, D.J. Skillings, M.A. Timmers, and B.W. Bowen (2011) Defining boundaries for ecosystem-based management: a multispecies case study of marine connectivity across the Hawaiian Archipelago. Journal of Marine Biology 2011: 1-13 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4260462/

Cotton, C.F., R.D. Grubbs, T.S. Daly-Engel, P.D. Lynch, and J.A. Musick (2011) Age, growth and reproduction of Squalus cf. mitsukuriifrom Hawaiian waters. Marine and Freshwater Research 62: 811-822 https://www.publish.csiro.au/mf/MF10307

Daly-Engel, T.S., R.D. Grubbs, K. Feldheim, B.W. Bowen, and R.J. Toonen (2010) Is multiple mating beneficial or unavoidable? Low multiple paternity and genetic diversity in the shortspine spurdog, Squalus mitsukurii. Marine Ecology Progress Series 403: 255-267 https://www.researchgate.net/publication/229089007_Is_multiple_mating_beneficial_or_unavoidable_Low_ multiple_paternity_and_genetic_diversity_in_the_shortspine_spurdog_Squalus_mitsukurii

Ebert, D.A., W.T. White, K.J. Goldman, L.J.V. Compagno, T.S. Daly-Engel, and R.D. Ward (2010) Resurrection and redescription of Squalus suckleyi (Girard, 1854) from the North Pacific, with comments on the Squalus acanthias subgroup (Squaliformes: Squalidae: Squalus). Zootaxa 2612: 22-40 https://www.researchgate.net/publication/235659630_Resurrection_and_redescription_of_Squalus_suckleyi_ Girard_1854_from_the_North_Pacific_with_comments_on_the_Squalus_acanthias_subgroup_Squaliformes_Squalidae

Nance, H.A., T.S. Daly-Engel, and P.B. Marko (2009) New microsatellite loci for the endangered scalloped hammerhead shark, Sphyrna lewini. Molecular Ecology Resources 9: 955-957 https://onlinelibrary.wiley.com/doi/10.1111/j.1755-0998.2008.02510.x

Bienfang, P., B. Oben, S. DeFelice, P. Moeller, K. Huncik, P. Oben, R. Toonen, T. Daly-Engel, and B. Bowen (2008) Ciguatera: Detection of neurotoxins in carnivorous reef fish from the coast of Cameroon, West Africa. African Journal of Marine Science 30: 533-540 https://www.researchgate.net/publication/229088997_Ciguatera_The_detection_of_neurotoxins_in_carnivorous_reef_fish_from_the_coast_of_Cameroon_West_Africa

Daly-Engel, T.S., R.D. Grubbs, B.W. Bowen, and R.J. Toonen (2007) Frequency of multiple paternity in an unexploited tropical population of sandbar sharks, Carcharhinus plumbeus. Canadian Journal of Fisheries and Aquatic Sciences 64: 198-204 https://www.researchgate.net/publication/229088996_Frequency_of_multiple_paternity_in_an_unexploited_population_of_sandbar_shark_Carcharhinus_plumbeus

Daly-Engel, T.S., R.D. Grubbs, K.N. Holland, R.J. Toonen, and B.W. Bowen (2006) Assessment of multiple paternity in single litters from three species of carcharhinid sharks in Hawaii. Environmental Biology of Fishes 76: 419-424 https://www.researchgate.net/publication/225632897_Assessment_of_multiple_paternity_in_single_litters_from_three_species_of_carcharhinid_sharks_in_Hawaii

Duncan, K.M. and T.S. Daly-Engel (2006) Using forensic science problems as teaching tools. The Science Teacher Nov. 06: 38-43 https://www.researchgate.net/publication/234663143_Using_Forensic_Science_Problems_as_Teaching_Tools