Sebastian Theis | PoeschLab

Thesis Title:

Assessing habitat enhancements to improve the restoration and development of northern boreal lakes (link to thesis).

Research Description:

My main research focus will be on how habitat enhancement in northern boreal lakes can help to improve restoration and offsetting efforts in lentic freshwater systems. I will specifically focus on the introduction of large woody debris (LWD) in riparian and littoral lake zones. Beneficial effects of LWDs range from habitat coupling over improved nutrient cycling to provision of rearing and spawning habitat for different aquatic species. While extensively studied for streams and rivers, little to no research has been done on lakes. To fill this knowledge gap we will construct LWD structures in designated lakes and measure their effect on water quality, nutrient availability, zooplankton, phytoplankton and fish biomass as well as habitat utilization. Sampling will be done in certain time intervals post-construction through electro-fishing, netting, sediment and water samples and visual surveys.

Highlighted by CBC News (link) and CBC Radio (link) and winner of Best Poster by the International Congress for Conservation Biology (link)!

Sebastian Theis, Post Doctoral Researcher (former Ph.D. Student)

Contact Information:

Previous Education:

Thesis Title:

Research Description:

Publications:

Theis S.*, Cartwright L., Chreston A., Wallace A., Graham B., Coey B., Little D., Poesch M.S., Portiss R., and J. Ruppert (In Press). Nearshore fish community changes along the Toronto Waterfront in accordance with management and restoration goals: Insights from two decades of monitoring. PLos One.

Theis S.* and M. S. Poesch. (2024). What makes a bank a bank? Differences and commonalities in credit calculation, application, and risks in mitigation banks targeting freshwater fish species and associated ecosystems. Environmental Management

Theis, S.* and M. S. Poesch. (2024). Mitigation bank applications for freshwater systems: Control mechanisms, project complexity, and caveats. PLOS One 19(2): e-292702.

Theis, S.*, Ruppert, J. L. W. and M. S. Poesch. (2023) Coarse woody habitat use by local fish species and structural integrity of enhancements over time in a shallow northern boreal lake assessed in a Bayesian modeling approach. Ecological Solutions and Evidence 4(2): e12200.

Theis, S.* Castellanos D.A., Hamann A. and M.S. Poesch. (2023) Small-bodied fish species from western United States will be under severe water stress by 2040. Conservation Science and Practice: e12856.

Theis, S.* Castellanos D.A., Hamann A. and M.S. Poesch. (2022) Exploring the potential role of habitat banks in preserving freshwater biodiversity and imperiled species in the United States. Biological Conservation 273: 109700.

Theis, S.* Koops, M. and M.S. Poesch. (2022) A meta-analysis on the effectiveness of offsetting strategies for harm to freshwater fishes. Environmental Management 70(5): 793-807.

Theis S.*, and M.S. Poesch (2022) Assessing conservation and mitigation banking practices and associated gains and losses in the United States. Sustainability 14: 6652.

Theis S.*, and M.S. Poesch (2022) Current capacity, bottlenecks, and future projections for offsetting habitat loss using mitigation and conservation banking in the United States. Journal for Nature Conservation 67:126159.

Theis, S., Ruppert, J., Shirton, J.* and M.S. Poesch (2022) Measuring beta diversity components and beneficial effects of coarse woody habitat introduction on invertebrate and macrophyte communities in a shallow northern boreal lake: implications for offsetting. Aquatic Ecology 56: 793-814.

Theis, S., Ruppert, J.W.R, Roberts, K.*, Koops, M., Minns, K. and M.S. Poesch. (2020) Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters. Conservation Biology 34(1) 41-53.