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Timothy P O'Brien

Timothy O’Brien is a Supervisory Fish Biologist stationed at the Great Lakes Science Center in Ann Arbor, Michigan.

Since 2004, I have conducted ecosystem assessments in Lake Huron and Lake Michigan that track long-term changes in fish populations. My work mainly focuses on Lake Huron where I lead the Pelagic Prey Fish Assessment Program. The field component of this research involves carrying out an integrated acoustic and mid-water trawl survey which includes Lake Huron’s three hydrogeomorphically distinct basins, the main basin, North Channel, and Georgian Bay. The primary deliverable of this work is to provide state, tribal, and provincial fishery managers with current data on abundance, size/age, and spatial distribution of prey-fish stocks that support fish species targeted in commercial and recreational fisheries. My research interests extend to include early life history processes in fish populations and factors affecting recruitment, growth variation, and distribution of important species including rainbow smelt (Osmerus mordax) and bloater (Coregonus hoyi).

I supervise of team of Biological Technicians in the Deepwater Sciences Branch who are responsible for conducting long-term fishery assessments in Lake Michigan and Lake Huron. Additionally, I oversee the fish age estimation laboratory for Lake Huron and Lake Michigan fishery assessment programs. In addition to my science program role, I serve as station supervisor for the Cheboygan Vessel Operations Base in Cheboygan, Michigan which is the home port for research vessels Sturgeon and Arcticus.