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Jason May


Jason T. May is an aquatic ecologist with the U.S. Geological Survey, California Water Science Center.  Mr. May has over 14 years experience working in California aquatic systems.  He has published on California fishes, benthic macroinvertebrates and benthic algae.  Mr. May  is currently involved in studies of the effects of urbanization on stream systems across the United States, modeling of responses of stream macroinvertebrate communities to land use changes,  and investigations of mercury and other trace metals contamination associated with abandon mine lands.  In the course of his work, Mr. May  has authored or coauthored over 30 scientific articles and reports.



    * Aquatic ecology
    * Ecology of aquatic invertebrates
    * Mercury bioaccumulation dynamics



    * B.S., Wildlife and Fisheries Biology, University of California, Davis, California.

Professional Societies

    * American Fisheries Society
    * North American Benthological Society


Professional Service

-CALFED Comprehensive Monitoring and Assessment Research Program,

Workgroups: Resident stream fish communities and Stream macroinvertebrate communities

-Sacramento River Watershed Program: Biological and Habitat Assessment Workgroup

-Sierra-Trinity Abandoned Mine Lands Forum


Journal Articles:
-In Preparation:
May, J.T., L.R. Brown, A.M.D. Brasher, T.M. Short, C.P. Konrad, and T.R. Maret. Responses of macroinvertebrate assemblages to landscape alteration and hydrologic infrastructure in streams of the Western USA.

Kennen, J.G. Sullivan, D.J., J.T. May, A.H. Bell, K.M. Beaulieu, and D.E. Rice. Temporal changes in benthic invertebrate and fish assemblages in streams of the North Central and Northeastern U.S.

Brown, L.R., J. T. May, Rehn, A.C. , P.R. Ode, and I. R. Waite. Modeling biological stream condition in the highly urbanized Southern California.

Rehn, A.C., J.T. May and P.R. Ode. An index of biotic integrity (IBI) for perennial streams of in California’s Central Valley. Submitted to Environmental Monitoring and Asssesment.

-In Press:

Waite, I.R.,  L.R. Brown, J.G. Kennen, J.T. May, T.F. Cuffney, J.L. Orlando and K.A. Jones. 2010. Comparison of watershed disturbance predictive models for stream benthic macroinvertebrates for three distinct western ecoregions. Ecological Indicators. doi: DOI: 10.1016/j.ecolind.2010.03.011

Cuffney, T.F., R.A. Brightbill, J.T. May, and I.R. Waite 2010. Responses of Benthic Macroinvertebrates to Environmental Changes Associated with Urbanization in Nine Metropolitan Areas of the Conterminous United States. Ecological Applications. doi:10.1890/08-1311


Brown, L.R., T.F Cuffney, J.F. Coles, F. Fitzpatrick, G. McMahon, J. Steuer, A. H. Bell, and  J. T. May.2009. Urban Streams Across the United States: Lessons Learned from Studies in Nine Metropolitan Areas. Journal of North American Benthological Survey. 28(4)1051-1069. DOI: 10.1899/08-153.1

Brown, L.R., M. B. Gregory, and J.T. May.2009. Relation of urbanization to stream fish communities and species traits in nine metropolitan areas of the United States. Urban Ecosystems. 12:391-416. DOI 10.1007/s11252-009-0082-2

Brown, L.R., J.T. May, and C.T Hunsaker. 2008. Species composition and habitat associations of benthic algal assemblages in headwater streams of the Sierra Nevada, California. Western North American Naturalist. 68:194-209.

Konrad, C.P., A.M.D. Brasher, and J.T. May.2008. Association of streamflow patterns and characteristics of benthic invertebrate assemblages in the western US. Freshwater Biology 53:1983 -1998

Brown, L.R. and J.T. May.2007. Aquatic vertebrate assemblages of the upper Clear Creek watershed, California. Western North American Naturalist 67:439-451.

Brown, L.R. and J.T. May. 2006. Variation in Spring Nearshore Resident Fish Species Composition and Life Histories in the Lower San Joaquin Watershed and Delta . San Francisco Estuary and Watershed Science. Vol. 4, Issue 2 (September 2006), Article 1.http://repositories.cdlib.org/jmie/sfews/vol4/iss2/art1

Ode, P.R., A.C. Rehn, and J.T. May. 2005. A quantitative tool for assessing the integrity of Southern Coastal California streams. Environmental Management. 35:493-504.

May, J.T.  and L.R. Brown. 2002. Fish communities of the Sacramento River Basin: implications for conservation of native fishes in the Central Valley, California.  Environmental Biology of Fishes. 63: 373-388.

Brown, L.R. and J.T. May. 2000. Macroinvertebrate assemblages on woody debris and their relations with environmental variables in the lower Sacramento and San Joaquin river drainages, California. Environmental Monitoring and Assessment 64:311-329.

Technical Reports:

-In Preparation:

May, J.T., Hothem, R.L Bauer, M.L.,., Brown, L.R. Concentrations of Mercury and Other Metals in Black bass (Micropterus spp.) from Whiskeytown Lake, Shasta County, California 2005: U.S. Geological Survey Open File Report.

M. L. Bauer, J.T. May, and L.R. Brown.Data report on aquatic inventory of the major streams of Whiskeytown National Recreation Area and Clear Creek, Shasta County, California. Open File Report.

Hothem, R. L., J.T. May and B.E. Brussee.PART 4. Site Characterization-biota monitoring in  Mercury in the sediments of the South Yuba River andHumbug Creek confluence: Concentrations, speciation and environmental fate Edited by M. Marvin-DiPasquale, C.N. Alpers, J.A. Fleck and R. Hothem SIR.

Konrad, C.P., A.M.D. Brasher, R.N Close, J.T. May and L.R. Brown. Streamflow characteristics as limiting factors on benthic invertebrate assemblages in streams across the western United States U.S. Geological Survey Fact Sheet

Alpers, C.N., J.T. May, R.L. Hothem, T.May, M.Saiki, and A.R. Stewart. Mercury Bioaccumulation in the Bear River Watershed, northwestern Sierra Nevada, California, 2003–06. U.S. Geological Survey Open File Report .


Rehn, A.C., J.T. May and P.R. Ode.2009. An index of biotic integrity (IBI) for perennial streams of in California’s Central Valley. Technical report of Central Valley Regional Water Quality Control Board.

Cuffney, T.F., G. McMahon, R. Kashuba, J.T. May, and I.A. Waite. 2009. Responses of benthic macroinvertebrates to environmental changes associated with urbanization in nine metropolitan areas of the conterminous United States. Pages 187-194, in, Webb, R.M.T., and Semmens, D.J., eds., 2009, Planning for an uncertain future—Monitoring, integration, and adaptation. Proceedings of the Third Interagency Conference on Research inthe Watersheds: U.S. Geological Survey Scientific Investigations Report 2009-5049, 292 p.

R. L. Hothem, J.T. May, M.L. Bauer, and D.R. Bergen 2008. Mercury in Biota from the BLM Reservoir, Buena Vista Mine, San Luis Obispo County, California, July 2007. USGS Data Summary Report 2008, 26p.

Hothem, R. L. J. T. May. 2008. Concentrations of Mercury and Other Metals in fish, and aquatic invertebrates from, Bodie Creek Watershed, California/Nevada 2007-8: U.S. Geological Survey Data Series Report 2008.

Hothem, R.L., J.T. May, L.R. Brown, J. N. Moore, J. Gibson and B. Rasmussen. 2008. Mobilization and bioaccumulation of metals and trace elements in aquatic biota from the Upper Clear Creek Watershed and Whiskeytown National Recreation Area, California, following the French Fire U.S. Geological Survey Data  Summary 2008.86 p.

Rytuba, J.J., R.L Hothem,., J.T May, C.P. Kim, D. Lawler, and Goldstein, D. 2008. Environmental impact of the Contact and Sonoma Mercury Mines on water, sediment, and biota in Anna Belcher and Little Sulphur Creek watersheds, Sonoma County, California: U.S. Geological Survey. Administrative Report 2008-1381,82p.

Rytuba, J.J., R.L.,Hothem,  J.T. May,  C.P. Kim, D. Lawler, D.Goldstein and B.E. Brussee.2008.Environmental impact of the Helen, Research, and Chicago Mercury Mines on water, sediment, and biota in upper Dry Creek watershed, Lake County, California: U.S. Geological Survey Administrative Report.

Slowey, A.J., J.J Rytuba,  R.L., Hothem, and May, J.T.2007. Mercury at the Oat Hill Extension Mine and James Creek, Napa County, California: Tailings, sediment, water, and biota,2003-2004: U.S . Geological Survey Open-File Report 2007-1132, 60 p.[http://pubs.usgs.gov/of/2007/1132/]

USDI French Fire Burned Area Rehabilitation Final Report for Fiscal Year 2006. 2006. Department of Interior, National Park Service, 66pgs.

May, J.T., R.L. Hothem, and C.N. Alpers.2005. Mercury concentrations in fishes from select water bodies in Trinity County, California, 2000-2002 USGS OFR05-1321.  Available online:  http://water.usgs.gov/pubs/ofr/2005/1321/

Alpers, C.N., M.P. Hunerlach, J.T. May, R.L. Hothem, H.E. Taylor, J.F. DeWild and D.A. Lawler. 2005.  Geochemical characterization of water, sediment, and biota affected by mercury contamination and acidic drainage from historical gold mining, Greenhorn Creek, Nevada County, California, 1999–2001 USGS SIR05-5251, Sacramento,CA. 293 pp. Available online:  http://water.usgs.gov/pubs/sir/2004/5251/

Alpers, C.N., M.P. Hunerlach, J.T. May, and R.L. Hothem. 2005. Mercury Contamination from historic gold mining in California: 2nd Edition. U.S. Geological Survey Fact Sheet 6 pp available at http://water.usgs.gov/pubs/fs/2005/3014/

Ashley, R.P., R.L. Hothem, J.T. May, and J.J. Rytuba. 2004. Preliminary report on mercury and methylmercury in  water, sediment, biota, and placer tailings, Hocker Flat project restoration area, Trinity County, California. USGS Admin. Report.  11pgs.

Brown, L.R. and J.T. May. 2004. Periphyton and macroinvertebrate communities at five sites in the San Joaquin River basin, California, during June and September 2001. USGS SIR. 04-5098, Sacramento, CA. 47 PP.

May, J.T. and L.R. Brown. 2001. Chinese mitten crab surveys of San Joaquin River Basin and Suisun Marsh, California, 2000. USGS OFR 01-396, Sacramento, CA. 20 pp.

Domagalski, J.L., D.L. Knifong, P.D. Dileanis, L.R. Brown, J.T. May, V.Connor and C.N. Alpers. 2000. Water Quality in the Sacramento River Basin, California, 1994-1998. USGS Circular 1215. 36 pp. Available online: http://water.usgs.gov/pubs/circ/circ1215/

May, J.T., R.L. Hothem, C.N. Alpers, and M.A. Law.2000. Mercury bioaccumulation in fish in a region affected by historic gold mining: the South Yuba River, Deer Creek, and  Bear River watersheds, California, 1999.  USGS OFR 00-367, Sacramento, California.  30 pp. Available online: http://ca.water.usgs.gov/rep/ofr00367/

Brown, L.R. and J.T. May. 2000.  Benthic macroinvertebrate assemblages and their relations with environmental variables in the Sacramento and San Joaquin river drainages, California, 1993-1997. USGS WRIR 00-4125. Sacramento, California. 25 pp.

Brown, L.R., T.J. Ford, M. Saiki, J.T. May, J. Merz, P.B. Moyle, and M.P. Marchetti. 2000. Baseline-monitoring program for hardhead and other river resident species. Draft monitoring program design supplied for the inclusion in the CALFED Bay-Delta Program baseline aquatic monitoring report. 9pp.

Harrington, J., P. Ode, J. Boles, N. Erman, V. Resh, P. Maslin, K. Lafferty, J.T. May, T. King, and K. Roby. 1998.  Monitoring, research, and assessment components for benthic macroinvertebrate communities. Appendix to Recommendations for the implementations and continued refinement of a comprehensive monitoring assessment, and research program, submitted by the Comprehensive Monitoring, Assessment, and Research Program Steering Committee to CALFED Bay-Delta Program, Sacramento, CA. 19 pp.

Brown, L. R., T. J. Ford, M. Saiki, J. T. May, and J. Merz. 1998. Monitoring, research, and assessment components for river resident species. Appendix to Recommendations for the implementations and continued refinement of a comprehensive monitoring assessment, and research program, submitted by the Comprehensive Monitoring, Assessment, and Research Program Steering Committee to CALFED Bay-Delta Program, Sacramento, CA. 15 pp.