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Darcy Lonsdale


Undergraduate Program Director



- Univ. of Maryland, College Park

Research Topics:

Ecology and physiology of marine zooplankton; food web dynamics of estuarine plankton and the impacts of harmful algal blooms.


  • Bio/Research


    My research addresses ecological problems related to marine invertebrates, especially copepods. I have focused on measuring and understanding the significance of variations in life history and physiology among estuarine copepod populations; e.g. as adaptive responses to age-specific mortality and water temperature. To understand the selective forces that may drive life-history variation, I have investigated planktonic trophic interactions, and have demonstrated the importance of predation in zooplankton feeding and population dynamics. I have used both laboratory studies showing the genetic basis of phenotypic variation among copepod populations, and field and modeling studies suggesting environmental factors that influence copepod fitness, to illustrate the significance of life-history variation.

    An exciting aspect of the School of Marine and Atmospheric Sciences is the opportunity to develop interdisciplinary projects with other faculty. These collaborations have resulted in new approaches. For example, I am currently involved in a collaborative research effort with Robert Cerrato (SoMAS) and David Caron (University of Southern California) to investigate the potential role of suspension feeding by hard clams ( Mercenaria mercenaria) in preventing blooms of the harmful phytoplankton species   Aureococcus anophagefferens  in Long Island, NY, bays. We are also interested in the relationship between hard clam feeding and the population dynamics of zooplankton, including heterotrophic protists and copepods.

  • Publications


    Treible, L.M.,   D.J. Lonsdale, and C.J. Gobler (2014) The role of the ctenophore   Mnemiopsis leidyi  in nutrient cycling in Long Island Sound, New York. Mar. Ecol. Prog. Ser. In Press

    McNamara, M.E.,   D.J. Lonsdale, and R.M. Cerrato (2014) Role of eutrophication in structuring planktonic communities in the presence of the ctenophore   Mnemiopsis leidyi. Mar. Ecol. Prog. Ser. In press

    McNamara, M.E. and   D.J. Lonsdale  (2014) Interannual differences in microplankton drive changes in the feeding and fecundity of Mnemiopsis leidyi  in a Long Island estuary. Est. Coast. Shelf Sci. 144:1-7.

    McNamara, M.E.,   D.J. Lonsdale, and R.M. Cerrato (2013) Top-down control of mesozooplankton by adult   Mnemiopsis leidyi  A. Agassiz 1865 influences microplankton abundance and composition enhancing prey conditions for larval ctenophores. Est. Coast. Shelf Sci. 133:2-10

    McNamara, M.E.,   D.J. Lonsdale, and R.C. Aller (2013) Elemental composition of   Mnemiopsis leidyi  A. Agassiz 1865 and its implications for nutrient cycling in a Long Island estuary. Est. Coasts 36:1253-1264

    Jiang, X.,   D. Lonsdale, and C. Gobler. 2010. Grazers and vitamins shape chain formation in a bloom-forming dinoflagellate, Cochlodinium polykrikoides. Oecologia 164:455-464

    Xiadong, J.,   D.J. Lonsdale  and C.J. Gobler. 2011. Rapid gain and loss of evolutionary resistance to the harmful dinoflagellate Cochlodinium polykrikoides  in the copepod Acartia tonsa. Limnology & Oceanography 56(3): 947-954.

    Jiang, Xiaodong,  D.J. Lonsdale , and C.J. Gobler. 2010. Density-dependent nutritional value of the dinoflagellates   Cochlodinium polykrikoides  to the copepod   Acartia tonsa. Limnol. Oceangr. 55:1643-1652

    McNamara, M.E.,   D.J. Lonsdale, and R.M. Cerrato. 2010. Shifting abundance of the ctenophore   Mnemiopsis leidy  and the implications for larval bivalve mortality. Mar. Biol. 157:401-412

    Jiang, X., Y. Tang,   D.J. Lonsdale, and C.J. Gobler (2009) Deleterious consequences of a red tide dinoflagellate   Cochlodinium polykrikoides  for the calanoid copepod   Acartia tonsa  Dana. Mar. Ecol. Prog. Ser. 390:105-116

    Lonsdale, D.J., R.M. Cerrato, R. Holland, A. Mass, L. Holt, R.A. Schaffner, J. Pan, and D.A. Caron. 2009. Influence of suspension-feeding bivalves on the pelagic food webs of shallow, coastal embayments. Aquat. Biol. 6:263-279

    Vigil, P., P.D. Countway, J. Rose, C.J.,   D.J. Lonsdale, C.J. Gobler, and D.A. Caron. 2009. Rapid shifts in dominant taxa among microbial eukaryotes in estuarine ecosystems. Aquat. Micro. Ecol. 54:83-100

    Smith, J.K.,   D.J. Lonsdale, C.J. Gobler, and D.A. Caron. 2008. Feeding behavior and development of Acartia tonsa nauplii on the browntide alga   Aureococcus anophagefferens. J. Plankton Res. 30:937-950

    Lonsdale, D.J., R.M. Cerrato, and D.A. Caron. 2007. Zooplankton changes associated with grazing pressure of northern quahogs ( Mercenaria mercenaria  L.) in experimental mesocosms. Est. Coast. Shelf Sci. 73:101-110

    Lonsdale, D.J., D.I. Greenfield, E.M. Hillebrand, R. Nuzzi, and G.T. Taylor. 2006. Microplanktonic community composition and trophic structure in two Long Island, New York, USA, embayments. J. Plankton Res. 28:891-905

    Deonarine, S.N., C.J. Gobler,   D.J. Lonsdale, D.A. Caron. 2006. The impact of zooplankton grazing and trophic structure on mortality of Aureococcus anophagefferens  in US mid-Atlantic estuaries. Aquat. Micro. Ecol. 44:181-195

    Pace, M.L. and   D.J. Lonsdale. 2006. Ecology of the Hudson Zooplankton Community. In: The Hudson River Estuary, J.S. Levinton and J. Waldman (eds.), Cambridge University Press, p. 217-229

    Gobler, C.J.,   D.J. Lonsdale, and G.L. Boyer. 2005. A review of the causes, effects, and potential mamagement of harmful brown tides caused by the alga   Aureococcus anophagefferens  (Hargraves et Sieburth). Estuaries 28:726-749

    Greenfield, D.I.,   D.J. Lonsdale, and R.M. Cerrato. 2005. Linking phytoplankton community composition with juvenile-phase growth in the northern quahog   Mercenaria mercenaria  (L.). Estuaries 28:241-251

    Cerrato, R.M., D.A. Caron,   D.J. Lonsdale, J.M. Rose, and R.A. Schaffner. 2004. Experimental approach to examine the effect of the northern quahog, Mercenaria mercenaria, on the development of blooms of the brown tide alga,   Aureococcus anophagefferens. Mar. Ecol. Prog. Ser. 281:93-108

    Caron, D.A., C.J. Gobler,   D.J. Lonsdale, R.M. Cerrato, R.A. Schaffner, J.M. Rose, N.J. Buck, G. Taylor, K.R. Boissonneault, and R. Mehran. 2004. Microbial herbivory on the brown tide alga,   Aureococcus anophagefferens: Results from natural ecosystems, mesocosms and laboratory experiments. Harmful Algae 3:439-457

    Greenfield, D.I.,   D.J. Lonsdale, R.M. Cerrato, and G.R. Lopez. 2004. Effects of background concentrations of   Aureococcus anophagefferens  (brown tide) on growth and feeding in the bivalve Mercenaria mercenaria. Mar. Ecol. Prog. Ser. 274:171-181

    Caron, D.A., R.A. Schaffner, D.M. Moran, M.R. Dennett,   D.J. Lonsdale, C.J. Gobler, R. Nuzzi, and R.I. McLean. 2003. Development and application of a monoclonal-antibody technique for counting   Aureococcus anophagefferens, an alga causing recurrent brown tides in the Mid-Atlantic United States. Appl. Environ. Micro. 69:5492-5502

    Greenfield, D.I. and   D.J. Lonsdale. 2002. Mortality and growth of juvenile hard clams,   Mercenaria mercenaria, during brown tide. Mar. Biol. 141:1045-1050

    Boissonneault-Cellineri K.R., M. Mehta,   D.J. Lonsdale, and D.A. Caron. 2001. Microbial food web interactions in two Long Island embayments. Aquatic Microbial Ecology 26: 139-155

    Caron D.A., M.R. Dennett,   D.J. Lonsdale, D.M. Moran, and L. Shalapyonok. 2002. Microzooplankton herbivory in the Ross Sea, Antarctica. Deep-Sea Res. II 47:3249-3272

    Lonsdale, D.J., D.A. Caron, M.R. Dennett, and R. Schaffner. 2000. Predation by Oithona spp. on protozooplankton in the Ross Sea, Antarctica. Deep-Sea Res II 47: 3273-3283

    Frey, M.A.,   D.J. Lonsdale, and T.W. Snell. 1998. Mate recognition and the role of chemical cues in an harpacticoid copepod. 1998. Philosophical Transactions Royal Society London B 353:745-751

    Lonsdale, D.J., R.P. Hassett, F.C. Dobbs, and J. Yen. 1998. Physiological traits associated with a reproductive-resting stage in Coullana canadensis  (Copepoda: Harpacticoida). Marine Biology 131:123-131

    Lonsdale, D.J., Frey, M.A., Snell, T.W. 1998. The role of chemical signals in copepod reproduction. Journal of Marine Systems 15:1-12

    Bricelj, V.M.,   Lonsdale, D.J.  1997.   Aureococcus anophagefferens: causes and ecological consequences of U.S. Mid-Atlantic coastal water “brown tides”. Limnology and Oceanography 42:1023-1038

    Lonsdale, D.J., Cosper, E.M., Doall, M. 1996. Effects of zooplankton grazing on phytoplankton size-structure and biomass in the lower Hudson River Estuary. Estuaries 19:874-865

    Lonsdale, D.J., Cosper, E.M., Kim, W.-S., Doall, M., Divadeenam, A., Jonasdottir, S.H. 1996. Food web interactions in the plankton of Long Island bays, with preliminary observations on brown tide effects. Marine Ecology Progress Series 134:247-263

    Gupta, S.,   Lonsdale, D.J., D.-P. Wang. 1994. The recruitment patterns of an estuarine copepod: A biological-physical model. Journal of Marine Research 52:687-710

    Weissman, P.,   Lonsdale, D.J., Yen, J. 1993. The effect of peritrich ciliates on the production of   Acartia hudsonica  (Pinhey) (Copepoda: Calanoida) in Long Island Sound. Limnology and Oceanography 38:613-622

    Lonsdale, D.J., Weissman, P., Dobbs, F.C. 1993. A reproductive-resting stage in an harpacticoid copepod, and the significance of genetically based differences among populations. Bulletin of Marine Science 53:180-193

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