Dr. Megan K. Otu

Aquatic Biologist

Study benthic ecology around freshwater cage aquaculture in Canada

Fisheries and Oceans Canada

Current research and/or projects

Current research includes measuring the sediment chemistry where benthic invertebrates live. I recently measured the concentration of dissolved gases, CH4 and H2S in the sediment pore water. At the same time, we sampled sediments for benthic invertebrates, nutrients (nitrogen, phosphorus), chemicals (copper, lead), and microprofiles of dissolved oxygen, pH and REDOX. This is because the breakdown of organic matter from the farm waste can release nutrients and gases, some can create acidic conditions for organisms. We are looking at how benthic invertebrates respond to organic matter deposition and what conditions they tolerate. This information is used to better inform licensing and regulation

Research and/or project statements

  • Net benthic invertebrate biomass around freshwater Rainbow Trout cage culture farms in Canada
  • Dissolved gas concentrations in farm sediments (biproducts of aerobic and anaerobic decomposition)
  • Benthic invertebrate community composition in relation to local sediment chemistry (multivariate analyses)
  • Benthic invertebrate tolerance of sediment chemistry and organic matter deposition rates

Education and awards


  • Doctor of Philosophy, Biology (2010), University of Waterloo, Waterloo, ON
  • Master of Science, Biology (2005) University of Waterloo, Waterloo, ON
  • Bachelor of Science, Zoology Major (2000), University of Manitoba, Winnipeg, MB


Key publications

Spaulding, S., M.K. Otu, A.P. Wolfe and J.S. Baron. 2015. Paleolimnological records of nitrogen deposition in shallow, high-elevation lakes of Grand Teton National Park, Wyoming, U.S.A. Arctic, Antarctic, and Alpine Research 47(4): 701-715.

Otu, M.K., C.L. Podemski, D. Bureau. 2014. Release of dissolved and particulate waste phosphorus from freshwater cage aquaculture. Canadian Science Advisory Secretariat. June 16-19, 2014.

Brahney, J., A.P. Ballantyne, B.L. Turner, S.A. Spaulding, M. Otu and J.C. Neff. 2014. Separating the influences of diagenesis, productivity and anthropogenic nitrogen deposition on sedimentary 15N variations. Organic Geochemistry 75:140-150.

Brahney, J., A.P. Ballantyne, P. Kociolek, S. Spaulding, M. Otu, T. Porwoll, & J.C. Neff. 2014. Dust mediated transfer of phosphorus to alpine lake ecosystems of the Wind River Range, Wyoming, USA. Biogeochemistry, 1-20.

Poste, A.E., D.C.G. Muir, M.K. Otu, R.I. Hall and R.E. Hecky. 2012. Past and present mercury flux to a West African crater lake (Lake Bosomtwe/Bosumtwi, Ghana). Science of the Total Environment 420:340-344.

Otu, M.K., P. Ramlal, P. Wilkinson, R.I. Hall and R.E. Hecky. 2011. Paleolimnological evidence of the effects of recent cultural eutrophication during the last 200 years in Lake Malawi, East Africa. Journal of Great Lake Research 37 (Suppl. 1 Lakes and Fisheries of Malawi): 61-74.

Otu, M.K., S. Spaulding. 2011. Cavinula pseudoscutiformes, Cavinula cocconeiformis, Chamaepinnularia shmassmannii, Chamaepinnularia mediocris, Chamaepinnularia soehrensis, Planothidium holstii, Karayevia nitidiformes. In Diatoms of the United States. Retrieved 2011, from http://westerndiatoms.colorado.edu/taxa/species

Spaulding, S., M.K. Otu, A. Wolfe and J. Baron. 2010. Atmospheric deposition of inorganic nitrogen in Grand Tetons NP determining biological effects on algal communities in alpine lakes. PMIS#119720. National Park Service Air Resources Division.

Puchniak M.K., F.E. Awortwi, P.O. Sanful, E. Frempong, R.I. Hall and R.E. Hecky. 2009. Effects of physical dynamics on the water column structure of Lake Bosomtwe/Bosumtwi, Ghana (West Africa). International Association of Theoretical and Applied Limnology 30(7): 1077-1081.