Research Document - 2013/108

Evaluating the current status of deepwater ciscoes (Coregonus spp.) in the Canadian waters of Lake Huron, 2002-2012, with emphasis on Shortjaw Cisco (C. zenithicus)

By N. E. Mandrak, T. C. Pratt, and S. M. Reid

Abstract

Historically, all six species of deepwater ciscoes (Coregonus spp.) and Cisco (C. artedi) present in the Great Lakes were found in Lake Huron. The last records of Deepwater Cisco (C. johannae) and Shortnose Cisco (C. reighardi) in Lake Huron were 1952 and 1985, respectively. Both species are now considered extinct. Of the species still present in other Great Lakes, the last record in Lake Huron of Blackfin Cisco (C. nigripinnis) was 1960, Shortjaw Cisco (C. zenithicus) was 1982, and the Kiyi (C. kiyi) was 1985. The purpose of this study was to evaluate the status of deepwater cisco species in the Canadian portion of Lake Huron. Between 2002 and 2006, cisco samples were collected by the Chippewas of Nawash First Nation, in collaboration with Fisheries and Oceans Canada (DFO), Ontario Ministry of Natural Resources (OMNR), and Parks Canada. Gillnets were bottom set at 71 locations in depths of 30-200 m. Across all years, a total of 2552 ciscoes were collected in Lake Huron. Of these 2552 ciscoes, 1538 were Bloater (C. hoyi), 72 were Cisco, 20 were Shortjaw Cisco, and 320 could not be identified to species. In 2007, a total of 20 bottom-set gillnets were set by DFO in the North Channel and northern main basin of Lake Huron.  A total of 433 ciscoes were collected. Bloater dominated the catch followed by a lesser number of Cisco; only two fish were identified as Shortjaw Cisco, caught in the same net set in the North Channel. In 2012, cisco samples were collected by the OMNR from locations near Lion’s Head and Tobermory.  Gillnets were bottom set at 15 locations in depths of 49-92 m. A total of 203 ciscoes were collected.  Of these, 110 were Bloater, 75 were Cisco, 17 were Shortjaw Cisco, and one specimen could not be identified to species. Shortjaw Cisco were collected from five sites near Lion’s Head, in depths of 77-92 m. The Shortjaw Cisco specimens were the first collected in Lake Huron since 1982.

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