Determining Stream Origin of Four Purported Walleye Stocks in Lake Erie Using Otolith Elemental Analysis

Content Provider	Semantic Scholar
Author	Bigrigg, Jennell Lynn
Copyright Year	2008
Abstract	Understanding stock structure and movement in aquatic organisms is necessary for successful population management. This is particularly important in exploited fishes, where stocks likely contribute differentially to the lake-wide population and the fishery. In Lake Erie, the walleye population is important, contributing both ecologically and economically to the lake and surrounding region. Although managed as a single unit, this population likely contains multiple stocks for which anecdotal evidence reveals that these stocks may exhibit different productivities, contributing differentially to the United States recreational and the Canadian commercial fishery. In this study, we sought to quantify homing behavior of walleye stocks and evaluate their contribution to the recreational fishery. By collecting water and spawning adult walleye (N=332) during 2003-2005 from Maumee, Sandusky, and Grand rivers and Toussaint Reef located in the western and central basins of Lake Erie, we could identify otolith chemical characteristics and compare them to the water from these locations. To assess their contribution, we collected three samples (N=300) from fish cleaning houses in Ottawa, Ashtabula, and Erie counties in Ohio during 2005. Again, otolith microchemistry identified element signatures, walleye were grouped, and the relative contribution of each purported stock was assessed. Extent of homing differed among the four spawning stocks. The Sandusky River had the highest site fidelity (92%), followed by the Maumee (60%) and Grand rivers (40%), and finally Toussaint Reef (37%). Toussaint Reef contributed >50% of the fish sampled from the recreational fishery, whereas Maumee, Sandusky, and Grand rivers contributed only 46% combined. By identifying stocks that exhibit high fidelity, we could protect them, thereby maintaining their genetic integrity. Armed with this stock-specific information, managers can protect or exploit populations in proportion to their contribution to the fishery.
File Format	PDF HTM / HTML
Alternate Webpage(s)	https://lakeerie.ohio.gov/Portals/0/Closed%20Grants/large%20grants/lepf04-18.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article