Research Interests

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 Marine Sciences Research Center 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.

Selected Publications

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

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. Plank. 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