Dr. Stephan Bullard, Post-doc Fellow
University of Connecticut
Department of Marine Sciences
Marine Sciences Building
1080 Shennecossett Rd.
Groton, CT 06340
Send an email to Dr. Bullard
Education
Ph. D. Marine Sciences (May 2000) University of North Carolina at Chapel Hill
B.S. Marine Biology, Magnum Cum Laude (May 1994) University of North Carolina at Wilmington
Research Interests
Larval Ecology
Plankton Ecology
Chemical Ecology
Current Research
Much of my work has focused on determining the relative risk of planktivory among marine habitats. To this end, I have developed the plankton tethering unit (PTU), a methodology that allows me to deploy and recover individual planktonic organisms (as small as 0.5 mm) in the field. Previously it has been very difficult to monitor individual plankton in situ. Thus, many basic questions about the relative risks of predation faced by planktonic organisms have remained unanswered. Additionally, because many marine invertebrates reproduce using a pelagic larval stage, this lack of knowledge has limited our understanding of the processes that affect benthic populations. Using PTUs, I have assessed the relative risks of planktivory among a variety of ecosystems including coral reefs, seagrass beds, and mangroves. I have found that the risk of predation varies spatially and temporally at very small scales and correlates positively with planktivorous fish abundance.
My current research at the University of Connecticut makes use of my PTU methodology and links planktonic predation risk to life history strategies in native and invasive ascidians. The goal of this research is to simultaneously monitor larval release, planktonic larval abundance, larval settlement, and the relative risk of predation faced by ascidian larvae during different diurnal periods. Data will allow me to determine whether different species of tunicates possess different life history characteristics and if these differences act to reduce the relative risk of predation on their larvae. Additionally, these data will allow me to determine whether invasive species possess fundamentally different life history characteristics than native species. In terms of basic research, my work will shed light on the life history constraints faced by benthic species and the mechanisms that they may use to overcome them. At an applied level, my work will provide insights into traits that help invasive species become established in new communities.
Additional work I have completed has focused on describing the taxonomic diversity of invertebrate larvae and in linking the ecological characteristics of larvae with larval abundance. To this end I have developed taxonomic keys for the crab larvae of North Carolina and for the ascidian and bryozoan larvae of Long Island Sound. I have also investigated the abundance and palatability of temperate invertebrate larvae to common predators.
Other Research Interests
My remaining work has examined anti-predator defenses in holoplanktonic organisms (organisms that spend their entire lives in the water column, such as jellyfish and ctenophores). In response to ecosystem-level changes, holoplankton are believed to be becoming dominant players in many marine systems, such as the Black Sea. Few predators, however, appear to consume holoplankton. To explain these observations, it had been hypothesized that many species of holoplankton possessed deterrent chemistry. I addressed this hypothesis while working on my Ph.D. (University of North Carolina at Chapel Hill, 2000; advisor Mark Hay). Although most of the holoplankton I examined were rejected by planktivorous fishes, few possessed chemical defenses. Rather, fishes rejected most holoplankton because of low nutritional quality or because the holoplankton possessed noxious stinging cells. In addition to advancing our basic knowledge of holoplankton, these data also have potential applications for fisheries. My data suggest that fishes alone may not be able to control macro-holoplankton populations. Thus, in environments where fish populations have been over harvested and replaced by holoplankton, it may be difficult to return to fish dominated systems even in the absence of fishing.
Publications
Bullard SG (2003) Larvae of anomuran and brachyuran crabs of North Carolina: A guide to the described larval stages of anomuran (Families: Porcellanidae, Albuneidae, and Hippidae) and brachyuran crabs of North Carolina, USA. Crustaceana Monogr vol 1. Brill Academic Publishers, Leiden, 142 pp.
Bullard SG, Hay ME (2002) Palatability of marine macro-holoplankton: nematocysts, nutritional quality, and chemistry as defenses against consumers. Limnol Oceanogr 47: 1456-1467
Bullard SG, Hay ME (2002) Plankton tethering to assess spatial and temporal patterns of planktivory over a coral reef and seagrass bed. Mar Ecol Prog Ser 225: 17-28
Bullard SG, Lindquist N, Hay ME (1999) Susceptibility of invertebrate larvae to predators: how common are post-capture larval defenses? Mar Ecol Prog Ser 191: 153-161
Hay ME, Stachowicz JJ, Cruz-Rivera E, Bullard SG, Deal MS, Lindquist N (1998) Bioassays with marine and freshwater macroorganisms. pp. 39-141 In: Haynes KF, Miller JG (eds) Methods in Chemical Ecology
Un-related Hobbies:
Hiking
Running
Medicine
Computer War Gaming (Panzer Campaigns, Combat Mission, Uncommon Valor)
Links of Interest (perhaps only to me):
War Games
http://www.hpssims.com
http://members.shaw.ca/gcsaunders/welcome.html
http://www.battlefront.com/index.htm
