Michael G. Hadfield, Ph. D.
- Professor of Zoology, Principal Investigator
- Marine Invertebrate Zoology & Conservation Biology
- ph: (808) 539-7319
- fax: (808) 599-4817
- Michael Hadfield CV
Researchers in the Hadfield laboratory have long had as their core theme the processes that occur when planktonic larvae of diverse marine invertebrate animals settle to the benthos and undergo the complex developmental processes of metamorphosis. Larvae of different species are known to respond to either dissolved or surface-bound cues to settlement and metamorphosis. In the Hadfield labs, these cues are investigated in terms of the developmental processes that they actually induce; the stimulatory cues are thus investigated as chemical ligands with specific receptors on the outer surfaces of larvae. Binding of ligand with receptors produces a cascade of behavioral and morphogenetic processes, which result in the profound morphological and physiological alterations that are summarized as metamorphosis.
Using especially a widely distributed tropical marine slug, Phestilla sibogae, and a common warm-water fouling organism, the tube worm Hydroides elegans, graduate student and postdoctoral researchers have collaborated with the P.I. to study the nature of the external cues, the site of their perception, the nature of receptor mechanisms, the role of the nervous system in promulgating the morphogenetic signal, and, most recently, the molecular events of metamorphic activation.
Other projects under investigation are related to the above, including: the mechanisms of invasion of a barnacle species, native to the Caribbean Sea, that first appeared in Hawaii in the last 10-20 years. The role played by larval recruitment and survival in successful marine invasions is a particular focus of this work. Additionally, in collaboration with Dr. Celia Smith of the U.H. Botany Department, some research in the Hadfield labs has sought better understanding of the mechanisms by which most tropical marine algae avoid the recruitment of sessile invertebrates to their surfaces, Drs. Hadfield and Smith also collaborate with U.S. Naval scientists in testing, in a tropical marine setting, the latest generation of marine coatings in resisting firm attachment by marine fouling organisms such as the barnacles and tube worms mentioned above.
Because invertebrate larvae, mostly in the range of 50 to 300 microns in diameter, have proven to be too small for effective use of intracellular nervous recording techniques, research in the Hadfield labs has broadened, in recent years, to include investigation of mechanisms and pathways of chemical perception in adults of Phestilla sibogae. They to carry out this effort, the lab has an excellent neurophysiology "rig" plus excellent microelectrode puller, recording instruments, micromanipulators, and other necessary equipment.
Another interest of Professor Hadfield is the conservation biology of a large group of tree snails unique to Hawaii. This work is described on his Department of Zoology web site. dditional information on this conservation effort can be found at the Hawaiian Tree Snail Conservation Lab, managed by Dr. Brenden Holland, a former post-doctoral fellow of Dr. Hadfield
Dr. Hadfield is lead Principal Investigator on a National Science Foundation training grant in the Undergraduate Research and Mentoring in the Biological Sciences (URM) program, which brings 13 Pacific Island undergraduates, mostly from community colleges in American Samoa and Micronesia, to the University of Hawaii for ten-week summer internships in environmental biology. Five of these students are supported for year-round internships as they complete four-year degrees at the University of Hawaii at Manoa. Since 2000, more than 80 Pacific Islanders have participated in this program, gone on to baccalaureate institutions and to graduate school and taken jobs critical for environmental conservation and natural resources management in their island groups. In 2009 - 2012, Dr. Hadfield is PI for a University of Hawaii program funded through an NSF-COSEE grant (Centers of Ocean Education Excellence), COSEE-Pacific Partnerships, at Oregon State University. The COSEE program provides funds for an additional three summer interns, drawn from Hawaii community colleges, who participate in the URM internship program, plus summer workshops for community college instructors.