Ann Bucklin

(Ph.D., University of California at Berkeley)

Professor of Marine Sciences

My research focus is the molecular ecology and evolution of zooplankton. My laboratory group uses diverse molecular approaches to study population genetics / genomics, phylogeography, biodiversity, and evolution of marine holozooplankton, especially copepods and euphausiids.

Environmental Genomics / Transcriptomics: In collaboration with Prof. Rachel O’Neill (UConn MCB and ISG), we are examining the genomic basis of adaptation of the Southern Ocean salp, Salpa thompsoni. We are working toward a comprehensive reference genome for this species that will enable the identification of genes and gene networks underlying physiological responses, and allow detection of natural selection driving the species’ adaptation to climate change. The completed salp reference genome will also provide a valuable foundational resource for other scientists (including ecologists, oceanographers, and climate change experts), working on this species. This effort is a continuation of earlier field studies in Antarctica focused on environmental transcriptomics of the Southern Ocean salp. See

Population Genetics / Genomics: We are using various genetic markers (including multigene sequences, Single Nucleotide Polymorphisms (SNPs), and Restriction-site Associated DNA (RAD) markers) to examine spatial patterns of genetic variation of zooplankton from small-scale patches to ocean-basin scale gyres, to measure population connectivity, and to infer pathways of transport in ocean currents.

Metabarcoding Zooplankton Biodiversity: We are analyzing zooplankton samples by metabarcoding, using High-Throughput Sequencing (e.g., Illumina MiSeq and NextSeq) of selected marker genes (COI and V4 and V9 hypervariable regions of 18S rRNA) for DNA extracted from unsorted zooplankton samples. Reference databases with DNA sequences from identified specimens necessary for taxonomic analysis of metabarcodes have been developed in partnership with taxonomic experts for the many zooplankton groups. The Census of Marine Zooplankton (CMarZ, see, an international collaboration 2004-2010, resulted in public databases of DNA barcode sequences, including mitochondrial cytochrome oxidase I (COI).  This global effort is continuing through a SCOR Working Group, MetaZooGene (SCOR WG157, see and, which seeks to re-examine metabarcoding evidence of zooplankton biodiversity and assemble reference databases for both COI and 18S rRNA. The overarching goal of these efforts is to ensure that metabarcoding will become a reliable, accurate, rapid and cost-effective approach for assessment of species diversity and food web dynamics of pelagic ecosystems.  The MetaZooGene mission and progress was summarized in a webinar sponsored by MBON (Marine Biodiversity Observing Network). See:

Food Web Dynamics in the Deep Ocean: An important focus for my lab is biodiversity and food web dynamics of the deep ocean.  See We are now collaborating with scientists and engineers from Woods Hole Oceanographic Institution on a project called the Ocean Twilight Zone (OTZ, see  Samples collected from mesopelagic depth zones (1,000 – 4,000 m) during research cruises in 2018 and 2019 provided comprehensive samples reflecting biodiversity across the pelagic assemblage.  Ongoing analysis of these samples is yielding new clues about the many unknown never-before-seen inhabitants of these dark regions, far below the surface. We are focusing on DNA metabarcoding analysis of the gut contents of mesopelagic fishes and salps, and will examine diet preference by comparing the diversity of gut contents and surrounding waters.

Research Projects

Molecular (metabarcoding) detection of invasive marine zooplankton species in the Gulf of Maine. Co-P.I.s Ann Bucklin & Paola Batta-Lona (UConn Marine Sciences). Marine Biological Laboratory, Plum Island Ecosystems LTER (P.I. Anne Giblin, MBL)

The Ocean Twilight Zone. Woods Hole Oceanographic Institution (Audacious Project): Lead PI H. Sosik (WHOI)

REU Site Mystic Aquarium: Investigating the consequences of global change on marine animals and their ecosystem. NSF / REU: Lead PIs M. Finiguerra (UConn) and T. Romano (Mystic Aquarium)

Genome assembly and analysis of the Southern Ocean salp, Salpa thompsoni. NSF / Polar Programs: Lead PI A. Bucklin (UConn); with co-PI Rachel J. O’Neill (UConn)

MetaZooGene: Toward a new global view of marine zooplankton biodiversity based on DNA metabarcoding and reference DNA sequence databases (SCOR Working Group 157). Scientific Committee for Ocean Research. See and

Current and Recent Research Group Members and Visitors

– Paola Batta-Lona (Postdoctoral Fellow, 2018 – 2021) Now Research Assistant Professor, UConn Marine Sciences, Email

– Melissa Wojcicki (M.S. Student, 2018 – 2021) Email

– Marta Carreton (Visiting Ph.D. Student, 2019) Institute of Marine Sciences (ICM-CSIC), Barcelona, Spain; Email

– Hayley DeHart (Research Technician, 2015 – 2018) Now at George Washington University; Email

– Heidi D. Yeh (M.S. Student, 2016-2018). Now at Rutgers University; Email

– Jennifer Questel (Postdoctoral Fellow, 2016-2017). Now at University of Alaska Fairbanks; Email

– Birgitte Nilsson (Visiting Graduate Student, 2016-2017, Roskilde University, Denmark) Email

– Temur Shvelidze (Visiting Scientist, 2018, Ilia State University, Tbilisi, Georgia) Email


Techniques in Marine Molecular Biology (MARN 3015/5015)  Molecular approaches include analysis of DNA and RNA variation using diverse technologies and platforms; genomics and transcriptomics; differential gene expression; population genetics and phylogenetics. Laboratory sessions will provide training in molecular protocols and procedures, with access to state-of-the-art molecular and bioinformatics facilities at UConn.  Marine applications include analysis of biodiversity from microbes to mammals, phylogeography and population connectivity, evidence of adaptation and evolution of marine organisms, and additional topics selected by students. (UConn – Avery Point, Fall 2022)

Seminar in Marine Biodiversity and Conservation (MARN 3812/ 5812) Co-taught with Dr. Tracy Romano. Presentations from guest experts and class discussions allow critical examination of state-of-the-art research, policy and regulatory frameworks of marine conservation biology and associated environmental, cultural, and socio-economic implications. (UConn & Mystic Aquarium; Spring 2021)

Marine Biology (MARN 3014) This course seeks to provide understanding of and appreciation for the diversity of marine life and the fundamental characteristics of marine environments. An important focus of the course is marine conservation biology, with guest lectures by Mystic Aquarium staff on endangered species, marine animal stranding, pollution, sound in the ocean, and other topics. (UConn – Avery Point; Spring semesters; Even years).  See

Oceanography Alumni

– Melissa Wojcicki – M.S. 2021

– Heidi D. Yeh – M.S. 2018

– Kayla Erikson – M.S. 2015

– Paola Batta Lona – Ph.D. 2014

– Ebru Unal – Ph.D. 2011

– Brian Ortman – Ph.D. 2008

Honors Received

Fulbright Senior Fellowship, Institute of Marine Research, Bergen, Norway (1993-1994)

Fellow of the American Association for the Advancement of Science (Elected 1995)

Member, Connecticut Academy of Science and Engineering (Elected 2006)

International Council for Exploration of the Sea (ICES) Service Award (2017)

International Council for Exploration of the Sea (ICES) Outstanding Achievement Award (2019)

University of Connecticut Faculty Excellence in Research and Creativity-Sciences Award (2020)

Publications (2010-2022)

For full reference list, see my ORCID page and profiles on GoogleScholar and ResearchGate


Bucklin, A., Batta-Lona, P.G., Questel, J.M., Wiebe, P.H., Richardson, D.E., Copley, N.J. and O’Brien, T.D. (2022) COI metabarcoding of zooplankton species diversity for time-series monitoring of the NW Atlantic continental shelf. Front. Mar. Sci. 9:867893.


Bucklin, A., K.T.C.A. Peijnenburg, K.N. Kosobokova, T.D. O’Brien, L. Blanco-Bercial, A. Cornils, T. Falkenhaug, R.R. Hopcroft, A. Hosia, S. Laakmann, C. Li, L. Martell, J.M. Questel, D. Wall-Palmer, M. Wang, P.H. Wiebe, A. Weydmann-Zwolicka (2021) Toward a global reference database of COI barcodes for marine zooplankton. Marine Biology 168 (78).

Bucklin, A., J.M. Questel, L. Blanco-Bercial, S.B. Smolenack, A. Frenzel, and P.H. Wiebe (2021) Population connectivity of the euphausiid, Stylocheiron elongatum, in the Gulf Stream (NW Atlantic Ocean) in relation to COI barcode diversity of Stylocheiron species. ICES Journal of Marine Science.

Bucklin, A., K.T.C.A. Peijnenburg, K.N. Kosobokova, and R. Machida (2021) New insights into biodiversity, biogeography, ecology, and evolution of marine zooplankton based on molecular approaches. ICES Journal of Marine Science,

Questel, J.M., R.R. Hopcroft, H.M. DeHart, K. Kosobokova, C. Smoot, and A. Bucklin (2021) Metabarcoding analysis of zooplankton biodiversity of the Pacific-Arctic Chukchi Borderlands region.  Marine Biodiversity 51 (4).

Thorrold, S.R.; A. Adams; A. Bucklin; K. Buesseler; G. Fischer; A. Govindarajan; P. Hoagland; D. Jin; A. Lavery; J. Llopez; L. Madin; M. Omand; P.G. Renaud; H.M. Sosik; P. Wiebe; D.R. Yoerger; W. Zhang (2021) Twilight Zone Observation Network: A Distributed Observation Network for Sustained, Real-Time Interrogation of the Ocean’s Twilight Zone, Marine Technology Society Journal, 55: 92-93.


Crouch, K.E., L. Blanco-Bercial, D.E. Richardson, N.J. Copley, P.H. Wiebe, and A. Bucklin (2020) Species-specific patterns of distribution and abundance of the cryptic copepods Pseudocalanus moultoni and P. newmani on Georges Bank (NW Atlantic Ocean) 1995-2012. Cont. Shelf Research 208: 104242.

DeHart, H.M., L. Blanco-Bercial, M. Passacantando, J.M. Questel, and A. Bucklin (2020) Pathways of pelagic connectivity: Eukrohnia hamata (Chaetognatha) in Arctic Ocean. Frontiers in Marine Science.

Yeh, H.D., J.M. Questel, K. Maas, and A. Bucklin (2020) Metabarcoding analysis of prey and microbiota composition of the copepod Calanus finmarchicus in the North Atlantic Ocean. Deep-Sea Research II.


Bucklin, A., Yeh, H.D., Questel, J.M., Richardson, D.E., Reese, B., Copley, N.J., and Wiebe, P.H. (2019) Time-series metabarcoding analysis of zooplankton diversity of the NW Atlantic continental shelf. ICES Journal of Marine Science 76: 1162–1176.  doi:10.1093/icesjms/fsz021.


Bucklin, A., K. DiVito, I. Smolina, M. Choquet, J.M. Questel, G. Hoarau and R.J. O’Neill (2018) Population Genomics of Marine Zooplankton. In: Population Genomics: Marine Organisms, O.P. Rajora and M. Oleksiak (Eds.), Springer Publ.  Manuscript as submitted available at:

Bucklin, A. (2018) Scientists are using DNA to study ocean life and reveal the hidden diversity of zooplankton. The Conversation. Published online June 7, 2018;

Nilsson, B., P.M. Jepsen, A. Bucklin and B.W. Hansen (2018) Environmental stress responses of marine copepods: Evidence of experimental handling artifacts for Acartia tonsa (Dana). Frontiers Mar. Science:


Batta-Lona, P.G., A. Maas, R. O’Neill, P.H. Wiebe, and A. Bucklin. 2017. Transcriptomic profiles of spring and summer populations of the Southern Ocean salp, Salpa thompsoni, in the Western Antarctic Peninsula region. Polar Biol. 40: 1261-€“1276. doi:10.1007/s00300-016-2051-6

Choquet, M., M. Hatlebakk, A.K.S. Dhanasiri, K. Kosobokova, I. Smolina, J.E. Soreide, C. Svensen, W. Melle, S. Kwasniewski, K. Eiane, M. Daase,V. Tverberg, S. Skreslet, A. Bucklin and G. Hoarau. 2017. Genetics redraws pelagic biogeography of Calanus. Biol.  Lett. 13: 20170588.

Snelgrove, P., E. Vanden Berghe, P. Miloslavich, N. Bailly, A. Brandt, A. Bucklin, and 23 others. 2017. Global patterns in marine biodiversity (Chapter 34). In The First Global Integrated Marine Assessment: World Ocean Assessment I.  Cambridge University Press. Pp. 501-524.

Wiebe, P.H., M.C. Benfield, and A. Bucklin. 2017. Sampling, preservation, and counting of samples: ii) Zooplankton, Chapter 10: In: Marine Plankton: A Practical Guide to Ecology, Methodology, and Taxonomy. Claudia Castellani and Martin Edwards [Eds.] Oxford University Press. doi:10.1093/oso/9780199233267.001.0001


Bucklin, A., P.K. Lindeque, N. Rodriguez-Ezpeleta, A. Albaina, and M. Lehtiniemi. 2016. Metabarcoding of marine zooplankton: Progress, prospects and pitfalls.  J. Plankton Res. Horizons 38: 393-400.  doi:10.1093/plankt/fbw023

Blanco-Bercial, L. and A. Bucklin. 2016. New view of population genetics of zooplankton: RAD-seq analysis reveals population structure of the North Atlantic planktonic copepod Centropages typicus. Molec. Ecol. 25: 1566-1580  doi: 10.1111/mec.13581

Jue, N., P.G. Batta-Lona, S. Trusiak, C. Obergfell, A. Bucklin, M. O’Neill, and R.J. O’Neill. 2016. Rapid evolutionary rates and unique genomic signatures discovered in the first reference genome for the Southern Ocean salp, Salpa thompsoni (Urochordata, Thaliacea). Genome Biol. Evol. 8: 3171-3186 doi: 10.1093/gbe/evw215

Nigro, L.M., M.V. Angel, K. Blachowiak-Samolyk, R.R. Hopcroft, and A. Bucklin. 2016. Identification, discrimination, and discovery of species of marine planktonic ostracods using DNA barcodes. PLoS-One 11(1): e0146327.  doi:10.1371/journal.pone.0146327

Questel, J.M., L. Blanco-Bercial, R.R. Hopcroft, and A. Bucklin. 2016. Phylogeography and connectivity of four sibling species of Pseudocalanus (Copepoda: Calanoida) in the North Pacific and Arctic Ocean. J. Plankton Res. doi:10.1093/plankt/fbw025

Wiebe, P.H., A. Bucklin, S. Kaartvedt, A. Rostad, and L. Blanco-Bercial. 2016. Vertical distribution and migration of euphausiid species in the Red Sea. J. Plankton Res.  doi:10.1093/plankt/fbw038


Bucklin, A., D.J. McGillicuddy, P.H. Wiebe and C.S. Davis. 2015. Habitat usage by the cryptic copepods Pseudocalanus moultoni and P. newmani on Georges Bank (Northwest Atlantic). Cont. Shelf Res. 111: 83-94. doi:10.1016/j.csr.2015.11.001

Nair, V.R., F.X. Kidangan, R.G. Prabhu, A. Bucklin and S. Nair. 2015. DNA barcode of Chaetognatha from Indian Waters. Indian J. Geo-Marine Sci. 44: 1366-1376.

Vinas, M.D., L. Blanco-Bercial, A. Bucklin, H. Verheye, J. Guilherme, F. Bersano, and S. Ceballos. 2015. Phylogeography of the copepod Calanoides carinatus s.l. (Kroyer) reveals cryptic species and delimits C. carinatus s.s. distribution in SW Atlantic Ocean. J. Exp. Mar. Biol. Ecol. 468: 97-104. doi:10.1016/j.jembe.2015.03.012


Aarbakke, O.N., A. Bucklin, C. Halsband, and F. Norrbin. 2014. Comparative phylogeography and demographic history of five sibling species of Pseudocalanus (Copepoda: Calanoida) in the North Atlantic Ocean. J. Exp. Mar. Biol. Ecol. 461: 479-488. doi:10.1016/j.jembe.2014.10.006

Blanco-Bercial, L., A. Cornils, N.J. Copley, and A. Bucklin. 2014. DNA barcoding of marine copepods: assessment of analytical approaches to species identification. PLOS-Currents Tree of Life [2014 June 23]. doi: 10.1371/currents.tol.cdf8b74881f87e3b01d56b43791626d2


Christie, A.E., V. Roncalli, P. Batta-Lona, M.D. McCoole, B.L. King, A. Bucklin, D.K. Hartline, and P.H. Lenz. 2013. In silico characterization of the insect diapause-associated protein couch potato (CPO) in Calanus finmarchicus (Crustacea: Copepoda). Comp. Biochem. Physiol. Part D 8: 45-€“57. doi:10.1016/j.cbd.2012.11.002

Unal, E., A. Bucklin, P.H. Lenz, and D.W. Towle. 2013. Gene expression of the marine copepod Calanus finmarchicus: Responses to small-scale environmental variation in the Gulf of Maine (NW Atlantic Ocean). J. exp. Mar. Biol. Ecol. 446:76-85. doi:10.1016/j.jembe.2013.04.020


Cepeda, G.D., L. Blanco-Bercial, A. Bucklin, C.M. Beron, M.D. Vinas. 2012. Molecular taxonomic analysis of three species of Oithona (Copepoda, Cyclopoida) from the Argentine sector of the South Atlantic Ocean: comparative analysis using 28S rDNA. PLoS-One 7 (4): e35861. doi:10.1371/journal.pone.0035861

Kozol, R., L. Blanco-Bercial, and A. Bucklin. 2012. Lack of genetic divergence between Calanus agulhensis and C. sinicus (Copepoda; Calanoida). PLoS-One 7(10): e45710. doi:10.1371/journal.pone.0045710

Lenz, P.H., E. Unal, R.P. Hassett, C.M. Smith, A. Bucklin, A.E. Christie, and D.W. Towle. 2012. Functional genomics resources for the North Atlantic copepod, Calanus finmarchicus: EST database and physiological microarray. Comp. Biochem. Physiol. Part D, 7: 110–123. doi:10.1016/j.cbd.2011.12.001


Aarbakke, O.N.S., A. Bucklin, C. Halsband-Lenk, and M.F. Norrbin. 2011. Discovery of Pseudocalanus moultoni Frost 1989 in Northeast Atlantic waters based on mitochondrial COI sequence variation. J. Plankton Res.  33: 1487-1495. doi: 10.1093/plankt/fbr057

Batta-Lona, P.G., A. Bucklin, T. Patarnello, N.J. Copley, and P.H. Wiebe, 2011. Population genetic variation of the southern ocean krill, Euphausia superba, in the western Antarctic Peninsula region using Single Nucleotide Polymorphisms (SNPs).   Deep-Sea Res. II 58:1652-1661 doi:10.1016/j.dsr2.2010.11.017

Blanco-Bercial, L. F. Ãlvarez-Marques, and A. Bucklin. 2011. Comparative phylogeography and connectivity of sibling species of the marine copepod Clausocalanus (Calanoida). J. Exp. Mar. Biol. Ecol. 404: 108-115 doi:10.1016/j.jembe.2011.05.011

Blanco-Bercial, L., J. Bradford-Grieve, and A.Bucklin. 2011. Molecular phylogeny of Calanoida (Copepoda). Mol. Phylogen. Evol. 59: 103-€“113 [ ]

Bortolotto, E., A. Bucklin, M. Mazzavilaa, L. Zane, and T. Patarnello. 2011. Gone with the currents: lack of genetic differentiation at the circum-continental scale in the Antarctic krill Euphausia superba. BMC Genetics 12: 32  doi:10.1186/1471-2156-12-32

Bucklin, A., D. Steinke, and L. Blanco-Bercial, 2011. DNA barcoding of marine metazoa. Annual Review of Marine Science 2011, Vol. 3: 471-508 doi:10.1146/annurev-marine-120308-080950

Govindarajan, A.F., A. Bucklin, and L.P. Madin. 2011. A molecular phylogeny of the Thaliacea. J. Plankton Res. 33:843-853 doi:10.1093/plankt/fbq157


Bucklin, A., R.R. Hopcroft, K.N. Kosobokova, L.M. Nigro, B.D. Ortman, R.M. Jennings, and C.J. Sweetman. 2010. DNA barcoding of Arctic Ocean holozooplankton for species identification and recognition. Deep-Sea Res. II 57:40-48. doi:10.1016/j.dsr2.2009.08.005

Bucklin, A., S. Nishida, S. Schnack-Schiel, P.H. Wiebe, D. Lindsay, R.J. Machida, and N.J. Copley. 2010. Chapter 13. A Census of Zooplankton of the Global Ocean, In: Marine Life: Diversity, Distribution, and Abundance. A. McIntyre [Ed.], Wiley-Blackwell, Oxford. Pp. 247-265

Bucklin, A., B.D. Ortman, R.M. Jennings, L. Nigro, C.J. Sweetman, N.J. Copley, and P.H. Wiebe. 2010. A €œRosetta Stone€ for zooplankton: DNA barcode analysis of holozooplankton diversity of the Sargasso Sea (NW Atlantic Ocean). Deep-Sea Res. II 57:2234-2247. doi:10.1016/j.dsr2.2010.09.025

Grabbert, S., J. Renz, H.-J. Hirche, and A. Bucklin. 2010. Species-specific PCR (SS-PCR) discrimination of species of the calanoid copepod Pseudocalanus, P. acuspes and P. elongatus, in the Baltic and North Seas. Hydrobiologia 652:289-297. doi:10.1007/s10750-010-0360-2

Jennings, R.M., A. Bucklin, H. Ossenbrugger, and R.R. Hopcroft. 2010. Analysis of genetic diversity of planktonic gastropods from several ocean regions using DNA barcodes. Deep-Sea Research II 57:2199-2210. doi:10.1016/j.dsr2.2010.09.022

Jennings, R.M., A. Bucklin, and A.C. Pierrot-Bults. 2010. Barcoding of arrow worms (Phylum Chaetognatha) from three oceans: genetic diversity and evolution within an enigmatic phylum. PLoS-ONE. doi:10.1371/journal.pone.0009949

Ortman, B. D., A. Bucklin, F. Pages, and M. Youngbluth. 2010. DNA barcoding of the Medusozoa. Deep-Sea Res. II 57:2148-2156. doi:10.1016/j.dsr2.2010.09.017

Sutton, T.T., P.H. Wiebe, L.P. Madin and A. Bucklin. 2010. Diversity and community structure of pelagic fishes to 5000 m depth in the Sargasso Sea. Deep-Sea Res. II 57:2220-2233. doi:10.1016/j.dsr2.2010.09.024

Unal, E. and A. Bucklin. 2010. Basin-scale population genetic structure of the planktonic copepod Calanus finmarchicus in the North Atlantic Ocean. Prog. Oceanogr. 87:175-186. doi:10.1016/j.pocean.2010.09.017

Wiebe, P.H., A. Bucklin, L.P. Madin, M.V. Angel, T. Sutton, F. Pages, R.R. Hopcroft, and D. Lindsay. 2010. Deep-sea holozooplankton species diversity in the Sargasso Sea, Northwestern Atlantic Ocean. Deep-Sea Res. II 57:2157-2166. doi:10.1016/j.dsr2.2010.09.018


Contact Information