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COSEWIC Assessment and Update Status Report on the Deepwater Sculpin (Western and Great Lakes-Western St. Lawrence Populations) in Canada


Global Range

The deepwater sculpin is restricted to deep, cold lakes in northern North America, primarily in Canada. In the United States, the deepwater sculpin is found only in the Great Lakes and a few inland lakes in Michigan and Minnesota (Scott and Crossman 1973). Generally, the deepwater sculpin occurs in lakes corresponding to areas which were formerly glaciated or accessible from proglacial lakes (Dadswell 1974).

Canadian Range

The deepwater sculpin is almost entirely restricted to Canada. In Canada, it occurs throughout formerly glaciated regions from the Gatineau region of southwestern Quebec through the Laurentian Great Lakes, northwest through Manitoba and Saskatchewan, and northward to Great Bear and Great Slave lakes (Parker 1988). An additional isolated population is also known from Upper Waterton Lake of southwestern Alberta (McAllister and Ward 1972) (Fig. 4). 

The known range is widespread, but patchy. This disjunct distribution may be due to the patchy occurrence of lakes with suitable environmental conditions that also occur in areas with former proglacial lake connections (Parker 1988). The known distribution of deepwater sculpin may also not adequately reflect their actual distribution. Information gaps about the species are due, in part, to the remote locations and associated logistic challenges of sampling ecologically suitable lakes, as well as the isolation of the species at great depths within lakes. Because of this, most distributional data are derived from incidental catch reports.

An intensive field sampling program targeting deepwater sculpin was conducted between May and October, 2004 (T. Sheldon, unpubl. data). The survey was conducted using modified minnow traps, gillnets and trawls, and included lakes with previously known occurrences and lakes with suitable bathymetry and postglacial history. A total of 35 lakes were sampled, and deepwater sculpin were collected in 20 of these lakes (Table 2). Sampling efforts and site occurrences spanned most of the known distribution of deepwater sculpin, ranging from Alexie Lake in the Northwest Territories in the northwestern portion of its range, to Thirty-One Mile Lake in Quebec in the extreme east, and Upper Waterton Lake in Alberta in the extreme southwest. Table 2 provides results of this survey.

Deepwater sculpin were found in four lakes in which they were previously not reported: Eagle and Teggau lakes in northwestern Ontario; and, Clearwater and Second Cranberry lakes in northwestern Manitoba. The occurrence of deepwater sculpin in Second Cranberry Lake is the first record of deepwater sculpin from the Nelson River watershed in Manitoba. The presence of deepwater sculpin in Eagle, Clearwater and Second Cranberry lakes is important, as it suggests that deepwater sculpin may be present in fairly accessible and popular fishing lakes, but have gone undetected due to the difficulty inherent in sampling smaller fish at the very bottom of these deep lakes. It also indicates that the presence of deepwater sculpin in other deep remote lakes is a strong possibility.


Table 2: Results of 2004 survey for the deepwater sculpin from inland lakes across its range
Trawl SE
Roddick LakeQC46 14' 54.4"75 53' 30.9"YesYes408480.338
Lac des IlesQC46 27' 36.0"75 31' 59.2"YesNo3914600
Thirty-One MileQC46 12' 43.1"75 48' 46.4"YesYes3063606
Heney LakeQC46 01' 16.4"75 55' 29.2"YesNo408480.330
Lake 259 (ELA)ON49 41' 19.9"93 47' 8.2"YesYes4404006
Teggau (ELA)ON49 42' 07.7"93 38' 53.1"NoYes396002
Lake 310 (ELA)ON49 39' 42.3"93 38' 13.6"YesNo3302200
Lake 258 (ELA)ON49 41' 41.6"93 48' 02.9"NoNo3602400
Eagle LakeON49 46' 15.5"93 36' 44.0"NoYes27232011
Burchell LakeON48 35' 07.6"90 37' 37.6"YesYes34030017
Fairbank LakeON46 27' 35.0"81 25' 37.0"YesYes3573206
Cedar LakeON46 02' 46.7"78 33' 11.9"YesNo816960.330
Saganaga LakeON48 14' 32.7"90 56' 02.7"YesYes384420.3310
Lake NipigonON49 27' 37.0"88 09' 57.6"YesYes300240.332
High LakeMB / ON49 42' 05.2"95 08' 01.2"NoNo3602200
Westhawk LakeMB49 45' 32.0"95 11' 28.0"YesYes1104920.336
George LakeMB50 15' 49.6"95 28' 16.2"YesYes9609001
Lake of the WoodsMB49 41' 28.7"94 48' 53.3"YesNo684360.330
Clearwater LakeMB54 04' 05.5"101 05' 33.7"NoYes924880.335
Second Cranberry LakeMB54 39' 08.5"101 09' 58.2"NoYes420400.3318
Lake AthapapuskowMB54 33' 01.2"101 39' 05.4"YesYes504480.339
Mirond LakeSK55 07' 20.3"102 48' 07.6"YesNo1200940.330
Lac La RongeSK55 12' 06.9"105 03' 59.2"YesNo1100920.330
Reindeer LakeSK56 23' 34.7"102 58' 22.2"YesYes3684604
Wollaston LakeSK58 14' 59.3"103 29' 44.4"YesYes5524804
Lac La PlongeSK55 08' 16.8"107 15' 43.2"YesYes506460.332
Chitty LakeNWT62 43' 42.0"114 07 57.2"NoNo7927200
Alexie LakeNWT62 29' 02.8"110 52' 57.9"YesYes8808601
Great Slave LakeNWT62 29' 15.0"110 52' 44.0"YesYes5289409
Cold LakeAB54 31' 23.0"110 06' 30.8"NoNo7489200
Peerless LakeAB56 40' 23.0"114 41' 04.0"NoNo506000
Upper Waterton LakeAB49 00' 17.9"113 54' 16.8"YesYes7680028
Upper KananaskisAB50 36' 41.4"115 09' 55.9"NoNo368000
Lake MinnewankaAB51 16' 02.2"115 25' 57.4"NoNo352000
Emerald LakeBC51 26' 25.1"116 31' 39.8"NoNo384000

Historical= historical record(s) of deepwater sculpin from the location previous to the 2004 survey; MT SE= minnow trap search effort; GN SE= gillnet search effort; Trawl SE= trawl search effort; N= number of deepwater sculpin found in each location.

Note: trawl was same type used as in Dadswell (1972). Gillnet panel was 1x15 m with 1 cm mesh size.

Lakes where deepwater sculpin were previously documented, but where 2004 sampling did not indicate their presence, included: Lac des Iles and Heney Lake in the Gatineau region of Quebec; Cedar Lake, Lake of the Woods, and Lake 310 of the Experimental Lakes area in Ontario; and, Mirond Lake and Lac La Ronge in northeastern Saskatchewan. The failure to capture deepwater sculpin from lakes in which they were previously found may be due to inadequate sampling for a species which is difficult to capture. However, the absence of deepwater sculpin from the two lakes in Quebec is more concerning, as it may be due to recently changing lake conditions, as both Lac des Iles and, especially, Heney Lake have been subject to increasing levels of eutrophication over the past decade. Finally, the absence of deepwater sculpin from Cedar Lake is most likely due to the misidentification of a single deepwater sculpin taken from a lake trout stomach over 30 years ago, as intense sampling of the lake over a three-day period in August 2004 yielded only 113 spoonhead sculpin (Cottus ricei) (Sheldon et al. unpubl. data.). Banville (Daniel Banville, Ministère des Ressources naturelles et de la Faune, Ste. Foy, QC; personal communication 2006) reported the recent collection of what was thought to be a deepwater sculpin from Lake Simoneau, near Mont Orford, Quebec, as well as an older record from Lake Memphremagog, also in the Eastern Townships. The Lake Simoneau fish has subsequently been identified by Claude Renaud of the Canadian Museum of Nature as a slimy sculpin (Cottus cognatus). The older report of a specimen from Lake Memphremagog has not been verified and is likely to be a slimy scupin as well, and thus is not accepted as bona fide.

All life stages of deepwater sculpin have been found in all the Great Lakes except Lake Erie (Smith 1985), where mature individuals have not been documented and only larval fish have been reported (e.g., Trautman 1981; Roseman et al. 1998; see below).