The migrations of anadromous cisco (Coregonus artedig and lake whitefish ( C . clupeaformis) in estuaries of eastern James Bay RODERICK MORIN' Centre dlEtudes Nordiques, De'partement de Biologie, Universitt Laval (Que'.), Canada G1K 7P4 JULIAN J. DODSON~ GIROQ, Dipartement de Biologie, Universite' Laval, Que'bec, GlK 7P4 AND GEOFFREY POWER' Centre &Etudes Nordiques, De'partement de Biologie, Universite' Laval (Que'.), Canada G l K 7P4 Received January 26, 198 1 MORIN, R., J. J. DODSON, and G. POWER. 1981. The migrations of anadromous cisco (Coregonus artedii) and lake whitefish (C. clupeaformis) in estuaries of eastern James Bay. Can. J. Zool. 59: 1600-1607. Experimental gill-netting and tagging programs were undertaken in the Eastmain and La Grande rivers of James Bay to determine the migratory patterns of anadromous cisco (Coregonus artedii) and lake whitefish (C. clupeaformis). Cisco and whitefish were found to differ in the distribution of juveniles during summer, in the upriver migration of mature fish, and in the selection of overwintering sites. Models are presented to illustrate the general life cycles of anadromous cisco and lake whitefish in James Bay. MORIN, R., J. 3. DODSON et G. POWER. 1981. The migrations of anadromous cisco (Coregonus artedii) and lake whitefish (C. clupeaformis) in estuaries of eastern James Bay. Can. J. Zool. 59: 1600-1607. Des programmes de pgche exptrimentale aux filets et des programmes de marquage furent Ctablis dans les rivikres Eastmain et La Grande de la Baie de James afin de dkteminer les mouvements migratoires du cisco (Coregonus artedii] et du grand corkgone (C. clupeaformis). La distribution des poissons juvCniles durant I'CtC diffkre chez ces deux espkces, de meme que la migration en amont des individus ?i maturitC et la selection des sites d'hivernage. Les observations ont conduit h 1'Claboration de modkles qui illustrent les cycles de vie du cisco et du grand corCgone anadrome de la Baie James. Introduction Although coregonine species occur frequently in Coregonine fishes are distributed over a wide range of estuaries, little has been published on the ecology of North America and Eurasia. Several species are found in anadromous populations in North America. In spite of diverse habitats throughout the cooler parts of the the importance of coreg~nine~ to the native fisheries of northern hemisphere. Of 12 coregonine species des- James and Hudson bays (Berkes 1977) and of the cribed by McPhail and Lindsey (1970) from north- concern expressed for this resource in view of CUKent western Canada and Alaska, the inconnu (Stenodus hydroelectric development (Penn 1975), few contribu- leucichthys nelma); lake whitefish (Coregonus clupea- tions have been made from studies in the James Bay formis); broad whitefish (C. nasus); least cisco (c. area. The present study reports on field studies con- sardinella); Arctic cisco (C. autumnalis); Bering cisco ducted primarily between 1973 and 1975 in the East- (C. laurettae); and round whitefish (Prosopium cyljn- main and La Grande rivers of James ~ a y , ~utbec. 1ts draceum) were reported as either anadromous or occur- PuVose was to describe the migratory Patterns ring in brackish water. In eastern Canada, it has been anadromous lake cisco and lake whitefish and to Propose known that lake cisco (C. artedii), lake whitefish, and models of their life cycles. round whitefish enter the salt water of James Bay and Hudson Bay since the accounts of Melville (1915) and Materials and methods Dymond (1933). The migrations of lake cisco and lake whitefish were studied by conventionaltagging programs and by recording changes in 'present address: Woods Hole Oceanographic Institution, the composition of catches in specific areas of the Eastmain Woods Hole, MA, U.S.A. 02543. and La Grande rivers (Fig. 1). The estuaries of both rivers were 2~uthor to whom reprint requests should be addressed. divided into two zones corresponding to the river mouth and 'present address: Department of Biology, University of the saltwater zone. The river mouth was usually fresh water Waterloo, Waterloo, Ont., Canada N2L 3G1. from surface to bottom, but was subject to frequent intrusions 0008-43011811081600-08$01.0010 0 1981 National Research Council of CanaddConseil national de recherches du Canada Can. J. Zool. Downloaded from www.nrcresearchpress.com by University of Laval on 03/19/12 For personal use only.