Location: Bowdoin / croesler

Earth and Oceanographic Science

Collin Roesler

Professor of Earth and Oceanographic Science

Contact Information

Earth & Oceanographic Science

Druckenmiller Hall - 120B

Teaching this semester

EOS 1505 / ENVS 1102. Oceanography

Collin Roesler
The fundamentals of geological, physical, chemical, and biological oceanography. Topics include tectonic evolution of the ocean basins; deep-sea sedimentation as a record of ocean history; global ocean circulation, waves, and tides; chemical cycles; ocean ecosystems and productivity; and the ocean’s role in climate change. Weekly labs and fieldwork demonstrate these principles in the setting of Casco Bay and the Gulf of Maine. Students complete a field-based research project on coastal oceanography.

EOS 2530 / ENVS 2287. Poles Apart

Collin Roesler
Compares and contrasts the tectonic evolution, geography, climate, glaciers and sea ice, ocean circulation and ocean biology of the Arctic and Antarctic regions. Emphasis on the polar regions’ role in global climate regulation and the sensitivity of these regions to climate change. In addition to scientific readings (text book chapters and journal articles), students read an array of first-hand accounts of polar exploration from the turn of the twentieth century.

Collin Roesler


Ph.D., University of Washington
M.S., Oregon State University
B.S., Brown University

Teaching Focus


Research Interests

response of ocean ecosystems to environmental forcing; Research foci: environmental optics with specialization in bio-optical modeling of phytoplankton biomass, production, ecophysiology, functional groups, particularly with respect to Harmful Algal Blooms; inherent optical properties of seawater and sea ice, particle-specific optics, optical instrumentation, ocean observing systems.

Cruise and Field Experience

Since 1989, I have spent over 300 days at sea on more than 35 cruises on major research vessels (over 90 days on Antarctic icebreakers). Additionally, I have spent approximately 40 days on Sea Ice Field Stations in the Arctic.


Academic Spotlight: Oceanographer Enriches Bowdoin's Coastal Connections

Cyanobacteria and Human Health: Merging Ecology, Epidemiology and Neurologic Disorders

(*indicates student authors)


*Belzile, C., C. S. Roesler, J. P. Christensen, N. Shakhova and I. Semiletov. 2006. Fluorescence measured using the WETStar DOM fluorometer as a proxy for dissolved matter absorption. Est. Coastal Shelf Sci. 67: 441-449.

Boss, E. and C. S. Roesler. 2006. Ch. 8. Over constrained linear matrix inversion with statistical selection (PDF) , pp. 42-46. In Z. P. Lee [ed] Remote Sensing of Inherent Optical Properties: Fundamentals, Tests of Algorithms, and Applications. IOCCG Report.

Babin, M, C. S. Roesler and J. J. Cullen [eds]. 2008. Real-Time Coastal Observing Systems for Ecosystem Dynamics and Harmful Algal Blooms. UNESCO Series Monographs on Oceanographic Methodology.

Roesler, C. S. and E. Boss. 2008. In situ measurement of the inherent optical properties (IOPs) and potential for harmful algal bloom (HAB) detection and coastal ecosystem observations, Chapter 5, pp. 153-206. In Babin, Marcel; Roesler, Collin S.; Cullen, John (Eds.). Real-time Coastal Observing Systems for Marine Ecosystem Dynamics and Harmful Algal Blooms: Theory, Instrumentation and Modelling. Paris: UNESCO.


*Pinto, J. L., C. S. Roesler, J. Peckenham, and H.H. Patterson. Treatment effects of copper sulfate and carbaryl on algal chlorophyll fluorescence chemistry. Submitted to Aquatic Toxicology.

*Proctor, C. W. and C. S. Roesler. In situ determination of phytoplankton concentration and composition using multiexcitation chlorophyll fluorescence. Submitted to Limnology and Oceanography.


Gardner, W. D. , J. C. Blakey, I.D. Walsh, M. J. Richardson, S. Pegau, J.R.V. Zaneveld, C. Roesler, M.C. Gregg, J. A. MacKinnon, H. M. Sosik, and A. J. Williams III. 2001. Optics, particles, stratification, and storms on the New England continental shelf. J.Geophys. Res. 106: 9473-9498.

Sosik, H. M., R. E. Green, W. S. Pegau, and C. S. Roesler. 2001. Temporal and vertical variability in optical properties of New England shelf waters during late summer and spring. J. Geophys. Res. 106: 9455-9472.

Bricaud, A., C. Roesler, J. Ishizaka, and J. Parslow. 2002. Bio-optical studies during the JGOFS-Equatorial Pacific program: A contribution to the knowledge of the Equatorial system. Deep Sea Res. 49: 2583-2599.

Roesler, C. S., C. W. Culbertson, S. M. Etheridge, R. Goericke, R. P. Kiene, L. G. Miller, and R. S. Oremland. 2002. Distribution, production, and ecophysiology of Picocystis strain ML in Mono Lake, California. Limnol. Oceanogr. 47: 440-452.

Roesler, C. S., and E. Boss. 2003. Spectral beam attenuation coefficient retrieved from ocean color inversion, Geophys. Res. Lett., 30(9), 1468-1472, doi:10.1029/2002GL016185.

*Simeon, J., C. Roesler, W. S. Pegau, and C. Dupouy. 2003. Sources of spatial variability in light absorbing components along an equatorial transect from 165°E to 150°W. J. Geophys. Res. 108(C10): 3333, doi:10.1029/2002JC001613.

*Werdell, P. J., and C. S. Roesler. 2003. Remote assessment of benthic substrate composition in shallow waters using multispectral reflectance. Limnol. Oceanogr. 48: 557-567.

*Belzile, C., W. F. Vincent, C. Howard-Williams, I. Hawes, M. James, M. Kumagai, C.S. Roesler. 2004Relationships between spectral optical properties and optically active substances in a clear oligotrophic lake. Water Resources Research 40:W12512, doi:10.1029/2004WR003090.

*Etheridge, S. M., G. P. Pitcher and C. S. Roesler. 2004. Depuration and transformation of PSP toxins in the South African abalone Haliotis midae, pp. 175-177. In: Steidinger, K. A., Lansdberg, J. H., Tomas, C. R., and Vargo, G. A. [eds.]. Harmful Algae 2002. Florida Fish and Wildlife Conservation Commission, Florida Institute of Oceanography, and Intergovernmental Oceanographic Commission of UNESCO.

*Etheridge, S. M. and C. S. Roesler. 2004. Geographic trends in Alexandrium spp. growth and toxicity as function of environmental conditions, pp. 65-67. In: Steidinger, K. A., Lansdberg, J. H., Tomas, C. R., and Vargo, G. A. [eds.]. Harmful Algae 2002. Florida Fish and Wildlife Conservation Commission, Florida Institute of Oceanography, and Intergovernmental Oceanographic Commission of UNESCO.

*Etheridge, S. M. and C. S. Roesler. 2004. Temporal variations in phytoplankton, particulates, and colored dissolved organic material based on optical properties during a Long Island brown tide compared to an adjacent embayment. Harmful Algae 3: 331-342.

Roesler, C. S., S. M. Etheridge and G. C. Pitcher. 2004. Application of an ocean color algal taxa detection model to red tides in the Southern Benguela, pp.303-305. In: Steidinger, K. A., Lansdberg, J. H., Tomas, C. R., and Vargo, G. A. [eds.]. Harmful Algae 2002. Florida Fish and Wildlife Conservation Commission, Florida Institute of Oceanography, and Intergovernmental Oceanographic Commission of UNESCO.

Babin, M., J.J. Cullen, C.S. Roesler, P.L. Donaghay, G.J. Doucette, M. Kahru, M.R. Lewis, C.A. Scholin, M.E. Sieracki, and H.M. Sosik. 2005. New approaches and technologies for observing harmful algal blooms. Oceanography 18: 210-227.

Boss, E., W. Peng and C. S. Roesler. 2005. Uncertainties of inherent optical properties obtained from semi-analytical inversions of ocean color. Applied Optics 44: 4074-4085.

*Etheridge, S. M. and C. S. Roesler. 2005. Effects of temperature, growth, irradiance, and salinity on photosynthesis, growth rates, total toxicity, and toxin composition for Alexandrium fundyense isolates form the Gulf of Maine and the Bay of Fundy. Deep-Sea Res. II 52: 2491-2500.


Perovich, D. K., C. S. Roesler, and W. S. Pegau. 1998. Variability in Arctic sea ice optical properties. J. Geophys. Res. 103(C1): 1193-1208.

Grenfell, T., D. G. Barber, A. K. Fung, A. J. Gow, K. C. Jezek, E. J. Knapp, S. V. Nghiem, R. G. Onstott, D. K. Perovich, C. S. Roesler, C. T. Swift, and F. Tanis. 1998. Evolution of electromagnetic signatures of sea ice from initial formation to the establishment of thick first-year ice. IEEE Trans. Geosci. and Rem. Sens. 36(5): 1633-1654.

Perovich, D. K., J. Longacre, D. G. Barber, R. A. Maffione, G. F. Cota, C. D. Mobley, A. J. Gow, R. G. Onstott, T. C. Grenfell, W. S. Pegau, M. Landry, C. S. Roesler. 1998. Field observations of the electromagnetic properties of first-year sea ice. IEEE Trans. Geosci. and Rem. Sens. 36(5): 1705-1715.

Roesler, C. S. 1998. Theoretical and experimental approaches to improve the accuracy of particulate absorption coefficients from the Quantitative Filter Technique. Limnol. Oceanogr. 43: 1649-1660.

Warren, S. G., C. S. Roesler, and R. E. Brandt. 1998. Solar radiation processes in the East Antarctic sea ice zone. Antarctic Journal US 32: 185 - 187.

Brandt, R. E., C. S. Roesler, and S. G. Warren. 1999. Spectral albedo, absorbance, and transmittance of Antarctic sea ice. Am. Meteorol. Soc. 5: 456-459.

*Leathers, R. A., C. S. Roesler, and N. J. McCormick. 1999. Ocean inherent optical property determination from in-water light field measurements. Appl. Opt. 38: 1-8.

Roesler, C. S. 1999. The color of icebergs, p. 336-337. In: J. Ruben [ed.], Antarctica. Lonely Planet.

Schofield, O., J. Grzymski, W. P. Bissett, G. Kirkpatrick, D. F. Millie, M. Moline, and C. S. Roesler. 2000. Optical monitoring and forecasting systems for harmful algal bloom: possibility or pipe dream? J. Phycol. 35: 1477-1496.


Roesler, C. S. and D. B. Chelton. 1987. Zooplankton variability in the California Current, 1951-1982. CalCOFI Rep. 28: 59-96.

Roesler, C. S., M. J. Perry, and K. L. Carder. 1989. Modeling in situ phytoplankton absorption from total absorption spectra. Limnol. Oceanogr. 34: 1512-1525.

Warren, S. G., C. S. Roesler, V. Morgan, R. Brandt, I. Goodwin, and I. Allison. 1993. Green icebergs formed by freezing of organic-rich seawater to the base of Antarctic ice shelves. J. Geophys. Res. 98(C4): 6921-6928.

Bricaud, A., C. S. Roesler, and J. R. V. Zaneveld. 1995. In situ methods for measuring the inherent optical properties of ocean waters. Limnol. Oceanogr. 40(2): 393-410.

Roesler, C. S. and M. J. Perry. 1995. In situ phytoplankton absorption, fluorescence emission, and particulate backscattering spectra determined from reflectance. J. Geophys. Res. 100(C7): 13,279-13,294.

Proceeding Publications

Iturriaga, R., A. Morel, C. Roesler, and D. Stramski. 1991. Individual and bulk analysis of the optical properties of marine particulates: examples of merging these two scales of analysis, pp. 339-347. In Demers, S. [ed.] Particle Analysis in Oceanography. NATO ASI Series, Vol. G 27. Springer Verlag, Berlin.
Roesler, C. S. and M. J. Perry. 1991. Modeling in situ phytoplankton absorption spectra from spectral reflectance: effects of spectral backscatter. In: P. Falkowski and A. D. Woodhead [eds.] Primary Productivity and Biogeochemical Cycles in the Sea, p. 527, Plenum Press, New York.

Iturriaga, R. and C.S. Roesler. 1994. Fluorometric characterization of dissolved and particulate matter in sea ice. SPIE Ocean Optics XII 2258: 920-932.

Roesler, C.S. and R. Iturriaga. 1994. Absorption properties of marine-derived particulate and dissolved material in Arctic sea ice. SPIE Ocean Optics XII 2258: 933-943.

Roesler, C.S. and J.R.V. Zaneveld. 1994. High resolution vertical profiles of spectral absorption, attenuation, and scattering coefficients in highly stratified waters. SPIE Ocean Optics XII, 2258: 309-319.

*Ciotti, A.M., J.J. Cullen, C.S. Roesler, and M.R. Lewis. 1996. Influence of phytoplankton size structure on the spectral attenuation coefficient in the upper ocean. SPIE Ocean Optics XIII: 280-285.

*McLeroy-Etheridge, S. L., and C. S. Roesler. 1998. Are the inherent optical properties of phytoplankton responsible for the distinct ocean colors observed during harmful algal blooms? SPIE Ocean Optics XIV 1: 109-116.

Roesler, C. S., and S. L. McLeroy-Etheridge*. 1998. Remote detection of harmful algal blooms. Ocean Optics XIV 1: 117-128.

*Etheridge, S. M., C. S. Roesler, H. M. Franklin, and E. Boss. 2002. Do bio-optical parameters and relationships apply to extreme algal blooms? Ocean Optics XVI Conference Proceedings.

Roesler, C. S. and E. Boss. 2002. A novel reflectance inversion model: Retrieval of beam attenuation coefficients and particle size distributions from ocean color. Ocean Optics XVI Conference Proceedings.

Pettigrew, N. and C. Roesler. 2003. Implementation of the Gulf of Maine Ocean Observing System (GoMOOS). Eur. Geophys. Soc. Geophys. Res. Abs., 5: 12741.

Pitcher, G. P., C. S. Roesler, and G. Nelson. 2003. The importance of surface boundary layer characteristics and advection in the development of red tide in the southern Benguela Upwelling System. Submitted, Proceedings of the Tenth International Conference for Harmful Algal Blooms.

Roesler, C. S. 2003. Achievements and limitations in ocean color detection of red tides: case studies in the Benguela Upwelling System and the Gulf of Maine, pp. 99-102. In: K. Furya, Y. Fukuyo, J. Ishizaka, and H. Kawamura [eds.], Proc. Workshop on Red Tide Monitoring in Asian Coastal Waters. Tokyo, Japan.

Pettigrew, N.R. and C. S. Roesler. 2005. Implementing the Gulf of Maine Ocean Observing System (GoMOOS)., IEEE Proceedings of Oceans '05 (Europe), Brest France, 2: 1362- 1369.

Roesler, C. S., A. H. Barnard, G. Aiken, T. Huntington, W. B. Balch, and H. Xue. 2006. Using optical proxies for biogeochemical properties to study land coverage and terrestrial inputs of organic carbon into coastal waters from the Penobscot Watershed to the Gulf of Maine. Proceeding of Ocean Optics XVIII, 9-13 October, Montreal.

*Sauer, M. J. and C. S. Roesler. 2006. Seasonal and spatial CDOM variability in the Gulf of Maine. Proceeding of Ocean Optics XVIII, 9-13 October, Montreal.

*Slade, W. M. R. Langner, E. Boss and C. Roesler. 2006. Retrieving in situ particulate absorption spectra in optically clear waters: An example from the Equatorial Pacific. Proceeding of Ocean Optics XVIII, 9-13 October, Montreal..

Pettigrew, N. P, C. S. Roesler, F. Neville, and H. E. Deese. 2007. An Operational Real-Time Ocean Sensor Network in the Gulf of Maine. Ocean Sensors.

Peer-Reviewed Publications Grants and Contracts

Current Grants

ECOHAB (NASA) - " Remote Assessment of Algal Functional Groups in the Absence of Extreme Blooms: Application to Alexandrium fundyense in the Gulf of Maine." with E. Laine, G. Teegarden, N. Pettigrew. 05/01/08 to 04/30/2011.

MWRA Subcontract- "Realtime assessment of phytoplankton blooms in Massachusetts Bay: Buoy A optical program". 09/01/08 to 09/01/10.

NASA Biological Oceanography - "Optical Oceanography from the single particle to the ecosystem: A summer class and a web book." with E. Boss, M. J. Perry and C. Mobeley. 1/1/2007 - 12/31/2009.

NASA IDS- Using remote sensing to understand carbon flow and its transformations from upland ecosystems into the coastal ocean ", with B. Balch and 4 others 06/01/2007 to 11/30/2009.

NASA ROSES- "Characterization of large and unusual Noctiluca blooms in the northern Arabian Sea and their role in carbon cycling during the winter monsoon", with J. Goes and H. Gomes. 12/1/2008 to 11/30/2011.

ONR - "Assessing variations in rivering optical constituents from in situ and remotely sensed data in coastal waters", CoPI with Andrew Barnard. 01/15/08 - 12/31/09.

1992 Session Chair: Optically Derived Primary Productivity. ASLO 92 Aquatic Sciences Meeting, Santa Fe, New Mexico. February.

1993 Chief Scientist: RV Wecoma, Oregon Coast

1994 Advisory Committee: NSF-Sponsored Symposium on Graduate Study in Science for

Undergraduate Women, April 14-17, Oregon State University.

1995 Chief Scientist: Sea Ice Field Station, Barrow, AK.

1998 Session Co-Chair: Coastal Mixing and Optics, AGU/ASLO 98 Ocean Sciences Meeting, San Diego, CA. February

2001 Co-Chair: Long Range Research Plan for Bigelow, presented plan at Board retreat.

2000-03 American Meteorological Society Committee on Polar Meteorology and Oceanography, three-year term.

2002-03 U.S. Representative developing research plan for GEOHAB Comparative Systems Studies: Upwelling Systems. Committee chaired by Dr. Grant Pitcher, Marine Coastal Management, Cape Town, South Africa.

2002-03 Organizing Committee: HABWatch Workshop to be held in Villefranche, France, June 2003.

2003-07 Planning Committee: Ocean Optics XVII and XVIII. Convened by the Oceanography Society and ONR. Four year term

2004 Moderator: Coastal Ocean Dynamics and Ecosystem structure Working Group. ORION, Jan. 2004, San Juan, PR.

2005-08 ORION Science and Technology Advisory Committee: 3 year appointment.

2005-07 Co-Chair: ORION STAC Coastal Subcommitte, with John Trowbridge. Duties include designing a $40M coastal infrastructure for the ORION porgram

2007 Co-Organizer: Kibbe Symposium on Alexandrium in the Gulf of Maine: Ecology, detection and management of Harmful Algal Blooms (Red Tides). April 3, 2007. Bowdoin College, Brunswich, ME.

2008 Session Co-Chair: ASLO Ocean Sciences Meeting, Global dynamics of CDOM, with Alison Branco, Orlando, Fl.

2008 Panelist: SeaGrant-sponsored Workshop on "Ecology of Gulf of Maine Atlantic Salmon in Nearshore Marine Ecology System". Gulf of Maine Research Institute, Portland, ME.