Professor Emeritus

Research Interests

Zooplankton ecology; copepod swimming and feeding; mesoscale and microscale links between physical, chemical, and biological processes in the sea; development of new instrumentation of biological oceanography.

Current Research

Role of food quality in feeding selectivity by zooplankton; biological physical interactions; zooplankton grazing processes; micro-scale plankton patterns using bio-optical instrumentation.
Plankton/Bio-Optical Oceanography Group


BS, Stanford University (Biology), 1973
MS, Stanford University (Chemistry), 1973
PhD, Duke University, 1977


Cowles, T.J., R.A. Desiderio, J.N. Moum, M. Myrick, D. Garvis, and S. Angel. 1990. Fluorescence microstructure using a laser/fiber optic profiler. Proc. Soc. Photo-Opt. Instrum. Eng., Ocean Optics X., 336-345

Miller, C. B., T. J. Cowles, P. H. Wiebe, N. J. Copley, and H. Grigg. 1991. Mechanisms of the resting phase in Calanus finmarchicus (Gunnerus). Mar. Ecol. Prog. Ser. 72: 79-91

Hood, R.R., S. Neuer, and T.J. Cowles. Autotrophic production, biomass, and species composition at two stations across an upwelling front. Mar. Ecol. Prog. Ser. 83: 221-232

Desiderio, R.A., T.J. Cowles, J.N. Moum, and M. Myrick. 1993. Microstructure profiles of laser induced chlorophyll fluorescence spectra: Evaluation of backscatter and forward scatter fiber optic sensors. J. Atmos. Oceanic Technol. 10: 209-224

Cowles, T.J., R.A. Desiderio, and S. Neuer. 1993. In situ characterization of phytoplankton from vertical profiles of fluorescence emission spectra. Mar. Biol. 115: 217-222

Cowles, T.J. and R.A. Desiderio. 1993. Resolution of biological microstructure through in situ fluorescence emission spectra: an oceanographic application using optical fibers. Oceanography 6: 105-111

Fessenden, L. and T.J. Cowles. 1994. Copepod predation on phagotrophic ciliates in Oregon coastal waters. Mar. Ecol. Prog. Ser. 107: 103-111

Neuer, S. and T.J. Cowles. 1994. Protist herbivory in the Oregon upwelling system. Mar. Ecol. Prog. Ser. 113: 147-162

Cowles, T.J. and L. Fessenden. 1995. Copepod grazing and finescale vertical distribution patterns during the Marine Light-Mixed Layers experiment. J. Geophys. Res. 100: 6677-6686

Neuer, S. and T.J. Cowles. 1995. Comparative cell-specific grazing rates in field populations of ciliates and dinoflagellates. Mar. Ecol. Prog. Ser. 125: 259-267

Desiderio, R.A., C. Moore, C. Lantz, and T.J. Cowles. 1997. Multiple excitation fluorometer for in situ oceanographic applications. Applied Optics 36: 1289-1296

Murphy, A.M. and T.J. Cowles. 1997. Effects of darkness on multi-excitatioin in vivo fluoresence and survival in a marine diatom. Limnol. Oceanogr. 42: 1444-1453

Cowles, T.J., R.A. Desiderio, and M-E. Carr. 1998. Small-scale planktonic structure: persistence and trophic consequences. Oceanography 11: 4-9

Potter, N. D. and T. J. Cowles. 2000. A high-speed, wireless network for ship-to-ship and ship-to-shore data exchange. J. Atmos. Oceanic Technol. 17: 963-970

Barth, J.A., T.J. Cowles, and S.D. Pierce. 2001. Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170o W during spring. J. Geophys. Res. 106: 13,879-13,902

Sherr, E.B., B.F. Sherr, and T.J. Cowles. 2001. Mesoscale variability in bacterial activity in the Northeast Pacific Ocean off Oregon, USA. Aquat. Microb. Ecol. 25: 21-30

Alldredge, A.L., T.J. Cowles, S. MacIntyre, J.E.B. Rines, P.L. Donaghay, C.F. Greenlaw, D.V. Holliday, M.M. Dekshenieks, J.M. Sullivan, J.R.V. Zaneveld. 2002. Occurrence and mechanisms of formation of a dramatic thin layer of marine snow in a shallow Pacific fjord. Mar. Ecol. Prog. Ser. 233: 1-12.

Barth, J.A., T.J. Cowles, P.M. Kosro, R.K. Shearman, A. Huyer, and R.L. Smith. 2002. Injection of carbon from the shelf to offshore beneath the euphotic zone in the California Current. J. Geophys. Res. 107:

Eisner, L., M. Twardowski, T. Cowles, and M.J. Perry. 2003. Resolving phytoplankton photoprotective:photosynthetic carotenoid ratios on fine scales using in situ spectral absorbtion measurements. Limnol. Oceanogr. 48: 632-646

Cowles, T.J. 2003. Planktonic layers: physical and biological interactions on the small scale. In: Handbook of Scaling Methods in Aquatic Ecology: Measurements, Analysis, Simulation. CRC Press, Boca Raton, FL.