Research topics: Marine and algal ecology; recruitment; plant-herbivore and predator-prey interactions
Research program: My interests span a wide range of intertidal and subtidal ecological questions. Students are encouraged to work in areas related to ongoing projects but flexibility is allowed in the selection of thesis projects. New students are encouraged to spend time in the field because many ecological problems can be addressed only with a solid understanding of natural history. Students are strongly encouraged to develop a strong inference approach to ecological questions. This often involves experimental manipulations based on sound experimental designs. My major foci at present are on recruitment and ecology of fucoid algae, especially Ascophyllum nodosum, and on the growth and reproductive ecology of green sea urchins. The alga is long-lived and the dominant intertidal alga throughout much of the North Atlantic ocean. Studies are directed towards understanding the mechanisms of attachment and the role of recruitment and dispersal on population regulation. Sea urchins are the second major marine resource in Maine. However, overharvesting created a boom and bust phenomenon, and understanding growth and reproductive processes may be crucial to recovery. Aspects of algal-herbivore interactions, including foraging behavior of invertebrates and their influence on the structure of intertidal assemblages, continue to be a component of my work. Behavioral studies on herbivores are an important but somewhat neglected aspect of community studies.
Selected Publications
Vadas, R.L., B.D. Smith, B. Beal, T. Dowling. 2002. Sympatric growth morphs and size bimodality in the green sea urchin (Strongylocentrotus droebachiensis). Ecological Monographs 72:113-132.
Dudgeon, S. J. E. Kubler, W.A. Wright, R.L. Vadas, and P.S. Petraitis. 2001. Natural variability in zygote dispersal of Ascophyllum nodosum at small spatial scales and its connection to recruitment. Functional Ecology 15:595-604.
Andrew, N., Y. Agatsuma, E. Ballesteros, A.G. Bazhin, E.P. Creaser, D.K.A. Barnes, L.W. Botsford, A. Bradbury, A. Campbell, J.D. Dixon, S. Einarsson, P. Gerring, K. Hebert, M. Hunter, S.B. Hur, C.R. Johnson, M.A. Juinio-Meņez, P. Kalvass, R.J. Miller, C.A. Moreno, J.S. Palleiro, D. Rivas, S.M.L. Robinson, S.C. Schroeter, R.S. Steneck, R.I. Vadas, D.A. Woodby and Z. Xiaoqi. 2002. Status and Management of World Sea Urchin Fisheries. Oceanogr. Mar. Biol. Annu. Rev. 40:343-425.
Vadas, R. L., B. Beal, T. Dowling and J. Fegley. 2000. Experimental field tests of natural algal diets on gonad index and quality in green sea urchin, Strongylocentrotus droebachiensis: a case for rapid summer production in post-spawned animals. Aquaculture 182:115-135.
Dudgeon, S., R.S. Steneck, I.R. Davison, R.L. Vadas. 1999. Coexistence of similar species in a space-limited Intertidal Zone. Ecological Monographs 69:331-352.
Vadas, R.L. and R.S. Steneck. 1995. Overfishing and inferences in kelp-sea urchin interactions. P. 509-524. In: Ecology of Fjords and Coastal Waters, H.R. Skjoldal, C. Hopkins, K.E. Erikstad and H.P. Leinaas (eds.), Elsevier Science B.V.
Vadas, R.L., S. Johnson and T. Norton. 1992. Recruitment and early mortality of algal spores. Brit. Phycol. J. 27:331-351.
Elner, R.W. and R.L. Vadas. 1990. Inference in Ecology: The sea urchin phenomenon in the Northwest Atlantic. American Naturalist 136:108-125.
Vadas, R.L., S. Miller and W.A. Wright. 1990. Recruitment in Ascophyllum nodosum Le jolis: Wave action as a source of mortality. Mar. Ecol. Prog. Ser. 61:263-272.
Other publications from this laboratory