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John Gunn

Research Interests

My research focuses on the effects of multiple stressors on aquatic ecosystems with a particular interest in the factors that affect recovery from disturbance.  Initially my research was concentrated on lake trout and other boreal fish species.  In recent years more and more of the work has been directed at understanding the ecology of benthic invertebrates key biogeochemical processes such as DOM production and release of contaminants such as Hg, processes that are primarily microbial in origins.


Publications (last 8 years)

Lescord G, TA Johnston, BA Branfireun and JM Gunn. 2018. Percent methylmercury in the muscle tissue of freshwater fish varies with body size, age, and among species. Environmental Toxicology and Chemistry. DOI 10.1002/etc.4233

Emilson E, MA Carson, KM Yakimovich, JM Gunn, NCS Mykytczuk, N Basiliko and AJ Tanentzap. 2018. Climate-driven shifts in sediment chemistry enhance methane production in northern lakes. Nature Communications. 1801 (2018) doi:10.1038/s41467-018-04236-2

Lescord GL, EJS Emilson, TA Johnston, BA Branfireun and JM Gunn. 2018. The optical properties of dissolved organic matter and their relation to mercury concentrations in water and biota across a remote freshwater drainage basin. Environmental Science and Technology. 52(6):3344-3353 doi: 10.1021/acs.est.7b05348

Emilson C, D Kreutzweiser, JM Gunn, N Mykytczuk. 2017. Leaf-litter microbial communities in boreal streams linked to forest and wetland sources of dissolved organic carbon. Ecosphere 8(2) e01678.10.1002/ecs2.1678

Jones FC, JM Gunn et al. 2017. Random forests as cumulative effects models: A case study of lakes and rivers in Muskoka, Canada. Journal of Environmental Management. DOI: 10.1016/j.jenvman.2017.06.011

Kielstra BW, SW Arnott and JM Gunn. 2017. Subcatchment deltas and upland features influence multiscale aquatic ecosystem recovery in damaged landscapes. Ecological Applications 27:2249-2261.

MacLeod, J., W. Keller, A.M. Paterson, R.D. Dyer and J.M. Gunn. 2017. Scale and watershed features determine lake chemistry patterns across physiographic regions in the far north of Ontario, Canada. J. Limnol. 76(1):211-220

Szkokan-Emilson EJ, BW Kielstra, SE Arnott, SA Watmough, JM Gunn and AJ Tanentzap. 2017. Dry conditions disrupt terrestrial-aquatic linkages in northern catchments. Global Change Biology. 23:117-126 DOI: 10.1111/gcb.13361

Tanentzap AJ, E Szkokan-Emilson, CM Desjardins, C Orland, K Yakimovich, R Dirszowsky, N Mykytczuk, N Basiliko, J Gunn. 2017. Bridging between litterbags and whole-ecosystem experiments: A new approach for studying lake sediments. J. Limnol. 76:431-437.

Tanentzap AJ, BW Kielstra, GM Wilkinson, M Berggren, N Craig, PA del Giorgio, J Grey, JM Gunn, SE Jones, J Karlsson, CT Solomon, ML Pace. 2017. Terrestrial ecosystems support lake zooplankton: large-scale synthesis reveals catchment and within-lake controls over use of cross-ecosystem resources. Science Advances 3, e1601765
Emilson C, D Kreutzweiser, J Gunn and N Mykytczuk. 2016. Effects of land use on the structure and function of leaf litter microbial communities in Boreal streams. Freshwater Biology. 61:1049-1061

Gunn JM, BW Kielstra and E Szkokan-Emilson. 2016. Catchment liming creates recolonization opportunity for sensitive invertebrates in a smelter impacted landscape. J. of Limnology. 75(s2):50-58.

Taylor NS, C Johnson, JA Kirwan, ND Yan, MR Viant, JM Gunn and JC McGeer. 2016. Predicting chronic copper and nickel reproductive toxicity to Daphnia pulex-pulicaria from whole-animal metabolic profiles. Env. Pollut. 212: 325-329

Taylor NS, J Kirwan, ND Yan, MR Viant, JM Gunn and JC McGeer. 2016. Metabolomics confirms that dissolved organic carbon mitigates copper toxicity. Env. Toxicol. Chem. 35:635-644

Volta P, ND Yan and JM Gunn. 2016. Past, present and future of the fish communities of Lake Orta (Italy), one of the world’s largest acidified lakes. J. Limnol. 75(s2):131-141

Yan ND, J Bailey, J McGeer, M Manca, W Keller, M Celis-Salgado and JM Gunn. 2016. Arrive, survive, and thrive: essential stages in the re-colonization and recovery of zooplankton in urban lakes in Sudbury, Canada J. Limnol. 75(s2):4-14

Cott PA, A Schein, BW Hanna, TA Johnston, DD MacDonald and JM Gunn. 2015. Implications of linear developments on northern fishes. Environmental Reviews 23: 177-190 DOI 10.1139/er-2014-0075.
Persaud A, A Luek, W Keller, FC Jones, P Dillon, JM Gunn and TA Johnston. 2015. Trophic dynamics of several fish species in lakes of a climatically sensitive region, the Hudson Bay lowlands. Polar Biology 38: 651-664

Stasko AD, TA Johnston and JM Gunn. 2015. Effects of water clarity and other environmental factors on trophic niches of two sympatric piscivores. Freshwater Biology 60: 1459-1474

Cott PA, A Hawkins, D Zeddies, B Martin, TA Johnston, J Reist, JM Gunn, and DM Higgs. 2014. Song of the burbot: Under-ice acoustic signaling by a gadoid fish. Journal of Great Lakes Research 40: 435-440.

Perron T, J Chételat, J Gunn, BE Beisner and M Amyot. 2014. Effects of experimental thermocline and oxycline deepening on methylmercury bioaccumulation in a Canadian shield lake. Env. Sci. Tech. 48(5):2626-34. doi: 10.1021/es404839t

Szkokan-Emilson EJ, S Watmough and JM Gunn. 2014. Wetlands as long-term sources of metals to receiving waters in mining-impacted landscapes. Environmental Pollution 192: 91-103.

Tanentzap AJ, E Szkokan-Emilson, B Kielstra, M Arts, N Yan and J Gunn. 2014. Forests fuel fish growth in freshwater deltas. Nature Communications. DOI: 10.1038/ncomms5077

Cott PA, TA Johnston, JM Gunn and DM Higgs. 2013. Hearing sensitivity of the burbot. Transactions of the American Fisheries Society 142: 1699-1704.

Cott PA, TA Johnston and JM Gunn. 2013. Stability in life history characteristics among burbot populations across environmental gradients. Transactions of the American Fisheries Society 142: 1746-1756.

Cott PA, TA Johnston and JM Gunn. 2013. Sexual dimorphism in an under-ice spawning fish: the burbot (Lota lota). Canadian Journal of Zoology 91: 732-740.

Luek A, G Morgan, B Wissel, J Gunn and CW Ramcharan. 2013. Impaired littoral energy pathways cause a shift to pelagic resources by fish in recovering lake food webs. Ecology of Freshwater Fishes DOI: 10.1111/eff.12030

Szkokan-Emilson EJ, B Kielstra, S Watmough and J Gunn. 2013. Drought-induced release of metals from peatlands in watersheds recovering from historical metal and sulphur deposition. Biogeochemistry.116:131-145 DOI 10.1007/s10533-013-9919-0

Tang RW-K, TA Johnston, JM Gunn and SP Bhavsar. 2013. Temporal changes in mercury concentrations of large-bodied fishes in the boreal shield ecoregion of northern Ontario, Canada. Science of the Total Environment 444: 409-416.

Stasko AD, JM Gunn and TA Johnston. 2012. Role of ambient light in structuring north-temperate fish communities: Potential effects of increasing dissolved organic carbon concentration with a changing climate. Environmental Reviews. 20(3): 173-190, 10.1139/a2012-010

Babin-Fenske JJ, TJS Merritt, JM Gunn, T Walsh and D Lesbarreres. 2012. Phylogenetic analysis of Hyalella colonization in lakes recovering from acidification and metal contamination. Can. J. Zool. 90(5): 624-629

Davidson J and JM Gunn. 2012. Effects of Land Cover Disturbance on Stream Invertebrate Diversity and Metal Concentrations in a Small Urban Industrial Watershed. Journal of Human and Ecological Risk Assessment. 18(5): 1078–1095

Cantin A, BE Beisner, JM Gunn, YT Prairie and JG Winter. 2011. Effects of thermocline deepening on lake plankton communities. Can. J. Fish. Aquat. Sci. 68(2):260-276.

Cott PA, TA Johnston and JM Gunn. 2011. Food web position of burbot relative to lake trout, northern pike, and lake whitefish in four sub-arctic boreal lakes. Journal of Applied Ichthyology. 27(s1):49-56
Szkokan-Emilson E, B Wesolek and J Gunn. 2011. Terrestrial organic matter as trophic subsidies that aid in the recovery of macroinvertebrates in industrially-damaged lakes. Ecological Applications. 21(6):2082-2093

Gunn JM and E Snucins. 2010. Brook charr mortalities during extreme temperature events in Sutton River, Hudson Bay Lowlands, Canada. Hydrobiologia. 650:79-84.

Gunn JM, C Sarrazin-Delay, B Wesolek, A Stasko, and E Szkokan-Emilson. 2010. Delayed recovery of benthic macroinvertebrate communities in Junction Creek, Sudbury, Ontario after the diversion of acid mine drainage. J. Hum. Ecol. Risk. Assess. 16:901-912.

Kreutzweiser DP, EA Muto, SB Holmes and JM Gunn. 2010. Effects of upland clearcutting and riparian partial-harvesting on leaf pack breakdown and aquatic invertebrates in boreal forest streams. Freshwater Biology. doi:10.1111/j.1365-2427.2010.02410.x

Luek A, GE Morgan, B Wissel, JM Gunn and CW Ramcharan. 2010. Rapid and unexpected effects of piscivore introduction on trophic position and diet of perch (Perca flavescens) in recovery lakes. Freshwater Biology. 55:1616-1627.

Wesolek BE, EK Genrich, JM Gunn and KM Somers. 2010. Use of littoral benthic invertebrates to assess factors affecting biological recovery of acid and metal damaged lakes. Journal of the North American Benthological Society. 29(2):572-585. doi: 10.1899/09-123.1

Wesolek B E, E Szkokan-Emilson and JM Gunn. 2010. Assessment of Littoral Benthic Invertebrate Communities at the Land–water Interface in Systems Recovering from Severe Acid and Metal Damage. J. Hum. Ecol. Risk. Assess. 16:536-559



Gunn, J.M., R.J. Steedman and R.A. Ryder. 2004. Boreal Shield Watersheds: Lake trout ecosystems in a changing environment. Lewis Publishers. 501 p.

Gunn, John M. (ed.) 1995. Restoration and Recovery of an Industrial Region. Springer-Verlag, New York, 358 p.