Raphael Ritson-Williams
Hawaii Institute of Marine Biology
46-007 Lilipuna Rd
Kaneohe, HI 96744
Phone: 808-236-7455
Fax: 808-236-7443
Research Interests
Fundamentally I’m interested in coral reef biodiversity, ecology, evolution and conservation. Some of my previous research has been to better understand coral reef biodiversity and chemical ecology at the organismal level. More recently my research (with many wonderful collaborators!) has focused on coral recruitment as a critical process for reef recovery. For my PhD research I’m especially interested in how coral genotypic diversity will respond to local and global stressors. A changing environment might be driving population dynamics for corals and a population’s ability to adapt to that variability could be determined by successful recruitment of more stress resistant genotypes. However, how recruitment influences population dynamics remains poorly studied and we still don’t have a good understanding of the natural levels of variability in stress tolerance of corals and their larvae. Understanding how stressors influence genotypic diversity in coral populations is necessary to predict the trajectory of coral survival and their ability to recover from acute and chronic stressors. Coral populations with decreasing genotypic diversity may be experiencing a serious genetic bottleneck that could threaten their ability to survive future stress events, leading to the destruction of this valuable ecosystem. 
B.Sc. in Biology/Ecology. The Evergreen State College 1998
M.S. in Biology University of Guam 2002
Ph.D. in Zoology, University of Hawai‘i at Manoa, in progress
Cunning R, Ritson-Williams R, Gates RD (2016) Patterns of bleaching and recovery of Montipora capitata in Kaneohe Bay, Hawaii USA. Marine Ecology Progress Series 551: 131-139.

Ritson-Williams R, Gates RD. 2016. Coral Bleaching in Hawai'i: A Window into Reefs of the Future. Integrative and Comparative Biology 56: E184-E184. 

Ritson-Williams, R., Arnold, S.N., Paul, V.J., Steneck, R.S. (2014) Larval settlement preferences ofAcropora palmata and Montastraea faveolata in response to diverse red algae. Coral Reefs, in press.
Pawlik, J.R., Amsler, C.D., Ritson-Williams, R., McClintock, J.B., Baker, B.J., Paul, V.J. (2013) Marine Chemical Ecology: A Science Born of Scuba. Smithsonian Contributions to Marine Science 39: 53-69.
Kirk, N., Ritson-Williams, R., Coffroth, M.A., Miller, M.W., Fogarty, N.D., Santos, S.R. (2013) Tracking transmission of apicomplexan symbionts in diverse Caribbean corals. PLOS One 8: e80618.
Yotsu-Yamashita, M., Abe, Y., Kudo, Y., Ritson-Williams, R., Paul, V.J., Konoki, K., Cho, Y., Adachi, M., Imazu, T., Nishikawa, T., Isobe, M. (2013) First identification of 5,11-Dideoxytetrodotoxin in marine animals, and characterization of major fragment ions of tetrodotoxin and its analogs by high resolution ESI-MS/MS. Marine Drugs 11: 2799-2813.
Olsen, K, Ritson-Williams, R., Ochrietor, J.D., Paul, V.J., Ross, C. (2013) Detecting hyperthermal stress in larvae of the hermatypic coral Porites astreoides: the suitability of using biomarkers of oxidative stress versus heat-shock protein transcriptional expression. Marine Biology 160: 2609-2618.
Baeza, J.A., Ritson-Williams, R., Fuentez, M.S. (2013) Sexual and mating system in a caridean shrimp symbiotic with the winged pearl oyster in the Coral Triangle. Journal of Zoology 289: 172-181. 
Ross, C., Ritson-Williams, R., Olsen, K, Paul, V.J. (2013) Short-term and latent post-settlement effects associated with elevated temperature and oxidative stress on larvae from the coral Porites astreoides. Coral Reefs 32: 71-79.
Morrow, K, Ritson-Williams, R., Ross, C., Liles, M.R, Paul, V.J. (2012) Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals. PLOS One 7: e44859.
Paul, V.J., Kuffner, I.B., Walters, L.J., Ritson-Williams, R., Beach, K.S., Becerro, M.A. (2011) Chemically mediated interactions between macroalgae Dictyota spp. and multiple life-history stages of the coral Porites astreoides. Marine Ecology Progress Series 426: 161-170. 
Paul, V.J., Ritson-Williams, R., Sharp, K. (2011) Marine chemical ecology in benthic 
environments. Natural Product Reports 28: 345-387. 
Sharp, K., Ritchie, K., Schupp, P., Ritson-Williams, R., Paul, V.J. (2010) Bacterial acquisition in juveniles of several broadcast spawning coral species. PLOS One 5: e10898.
Ritson-Williams (2010) Surface brooding in the Caribbean gorgonian Pterogorgia anceps. Coral Reefs 29: 437.
Ritson-Williams, R., Paul, V.J., Arnold, S., R.S. Steneck (2010) Larval settlement preferences and post-settlement survival of the threatened Caribbean corals Acropora palmata and A. cervicornis. Coral Reefs 29: 71-81.
Ross, C., Ritson-Williams, R., Pierce, R., Bullington, J. B., V. J. Paul (2010) Effects of the Florida red tide dinoflagellate, Karenia brevis, on oxidative stress and metamorphosis of larvae of the coral Porites astreoides. Harmful Algae 9: 173-179.
Matthew, S., Ratnayake, R., Becerro, M.A., Ritson-Williams, R., Paul, V.J., Luesch, H. (2010) Intramolecular modulation of serine protease inhibitor activity in a marine cyanobacterium with antifeedant properties. Marine Drugs 8: 1803-1816.
Ritson-Williams, R., Arnold, S., Fogarty, N., Steneck, R.S., Vermeij, M.J.A., V.J. Paul (2009) New perspectives on ecological mechanisms affecting coral recruitment on reefs. Smithsonian Contributions to Marine Science 38: 437-457.
Kuffner, I.K., Paul, V.J., Ritson-Williams, R., Hickey, T.D., Walters, L.J. (2009) Reef 
communities in the Dry Tortugas (Florida, USA): Baseline surveys for the new no-take area. Proceedings of the 11th Inter Coral Reef Symposium: 311-315.
Ritson-Williams, R., Shjegstad, S.M., Paul V.J. (2009) Larval metamorphosis of Phestilla spp. in response to waterborne cues from corals. J Exp Mar Biol Ecol 375: 84-88.
Gunasekera, S. P., Ritson-Williams, R., Paul V.J. (2008) Carriebowmide, a new 
cyclodepsipeptide from the marine cyanobacterium Lyngbya polychroa. Journal of Natural Products 71: 2060-2063.
Paul, V. J. and Ritson-Williams, R. (2008) Marine chemical ecology. Natural Product Reports 25: 662-695.
Paul, V.J., Arthur, K.E., Ritson-Williams, R., Ross, C., Sharp, K. (2007) Chemical defenses: from compounds to communities. Biological Bulletin 213: 226-251.
Ritson-Williams, R., Shjegstad, S.M., Paul V.J. (2007) Larval metamorphic competency in four species ofPhestilla (Gastropoda; Opisthobranchia). J Exp Mar Biol Ecol 351: 160-167.
Ritson-Williams, R. and Paul, V.J. (2007) Marine benthic invertebrates use multimodal cues for defense against reef fishes. Marine Ecology Progress Series 340: 29-39. 
Ritson-Williams, R. and Paul, V.J. (2007) Periclimenes yucatanicus and Periclimenes rathbunae on unusual corallimorph hosts. Coral Reefs 26: 147.
Kuffner, I., Walters, L., Becerro, M., Paul, V.J., Ritson-Williams, R., Beach, K. (2006) Inhibition of coral recruitment by macroalgae and cyanobacteria. Marine Ecology Progress Series 323: 107-117. 
Paul, V. J., Puglisi, M., Ritson-Williams R. (2006) Marine chemical ecology. Natural Product Reports 23(2): 153-180.
Ritson-Williams, R., Yotsu-Yamashita, M., Paul V.J.  (2006) Ecological functions of tetrodotoxin in a deadly polyclad flatworm. P Natl Acad Sci USA 103: 3176-3179.
Ritson-Williams, R., Paul, V.J., Bonito, V. (2005) Marine benthic cyanobacteria overgrow coral reef organisms. Coral Reefs 24: 629.
Ritson-Williams, R., Becerro, M., Paul, V.J. (2005) Spawning of the giant barrel sponge Xestospongia muta in Belize. Coral Reefs 24: 160.
Ritson-Williams, R., Shjegstad, S.M., Paul V.J. (2003) Host specificity of four corallivorous Phestilla nudibranchs.  Marine Ecology Progress Series 255:207-218.
Newman, L., Paulay, G., Ritson-Williams R. (2003) Checklist of polyclad flatworms (Platyhelminthes) from Micronesian coral reefs. Micronesica 35/36: 189-199.
*= Presentation speaker,  † = Invited speaker, § = Poster presentation
Most Recent 8 of 30
Ritson-Williams, R.* and V. J. Paul. Global and local stressors reduce coral recruitment March 2013. University of Hawaii Albert L. Testers Memorial Symposium.
Ritson-Williams, R.* and V. J. Paul. Patterns and Processes Driving Coral Recruitment. February 2013. University of Hawaii Marine Biology Graduate Seminar.
Ritson-Williams, R.*, V. J. Paul, S. Arnold, R.S. Steneck, C. Ross. Positive and negative effects of benthic algae on coral recruitment. July 2012. International Coral Reef Symposium.
Ritson-Williams, R.*, V. J. Paul. Coral recruitment in the garden of good and evil. October 2011. Invited public lecture CIEE Research Station (Bonaire).
Ritson-Williams, R.*, V. J. Paul, S. Arnold, R.S. Steneck. Picky coral larvae select specific coralline species. March 2011. Benthic Ecology Meeting.
Ritson-Williams, R.*, V. J. Paul, S. Arnold, R.S. Steneck.  Do coral larvae chose between species of coralline algae. January 2010 Society for Integrative and Comparative Biology.
Ritson-Williams, R.*, C. Ross, V. J. Paul. Global and local stressors interact to reduce coral larval survival and settlement. March 2010 Benthic Ecology Meeting.
Ritson-Williams, R.*, V. J. Paul, S. Arnold, R.S. Steneck.  Towards a better understanding of coral recruitment. October 2010 Linking Science to Management: A Conference and Workshop on the Florida Keys Marine Ecosystem.
2012: Teaching multiple grade levels about marine diversity, ecology, evolution and conservation: Mililani-Mauka School (HI)-1st grade 4/13, Star of the Sea (HI)-6th grade 2/13, St. Andrews (FL)-2ndgrade 
2012: Photo in New York Times article about coral spawning.
2012: Public lecture “Medicines from the Sea” for the Smithsonian Marine Ecosystems Exhibit.
2010: Presented five public lectures about marine ecology and diversity.
Funding Sources
UH Edmondson Grant.
UH Maybelle Roth Fellowship (ARCS)
Lerner-Gray Fund (American Museum of Natural History).