Thunder Bay District, Ontario

Dog Lake

Aerial photograph of Dog Lake.
Surface
145.9 km²
Shoreline
373 km294 mainland + 79 island shore
Islands
121
Max depth
100.0 m
Depth contours
209
Dog Lake from the air, from the Ontario Imagery Web Map Service.

Where Dog Lake is

Dog Lake lies in the District of Thunder Bay.

How deep is Dog Lake?

The deepest mapped contour on Dog Lake is 100.0 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 209 depth contours for Dog Lake.

248121620243040506070809024608121004070202248090247024408212816202420284016502024302424204016
The deepest charted contour on Dog Lake, 100.0 meters. The circle marks the centre of that contour.

See also Ontario's Largest and Deepest Lakes

Surveyed Depths

Ontario has surveyed the depths of several thousand of its lakes over more than half a century. Later surveys were conducted by boat with satellite positioning and produced hundreds of thousands of soundings per lake. Earlier surveys were charted by running transects across the water and drawing depth contours by hand.

Water quality

Ontario’s Lake Partner Program is a volunteer monitoring network. Participants collect water samples for phosphorus analysis and measure water clarity through the summer with a Secchi disk. Most sites are sampled for phosphorus once a year, in spring, and some several times a year between spring and fall. Phosphorus in many lakes rises through the summer, so the two kinds of average are measured on different bases.

Phosphorus is the nutrient that controls how much algae a lake can grow. A lake with little phosphorus stays clear and supports cold-water fish such as lake trout. As phosphorus rises, algae increase, the water clouds, and oxygen in the deep water falls as the algae decay. The province classifies each monitoring site by its average phosphorus:

  • Oligotrophic, below 10 micrograms per litre: clear water and low algae.
  • Mesotrophic, from 10 to 20: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom.
  • Eutrophic, above 20: nutrient-rich water, prone to algal blooms and low oxygen at depth.

No monitoring site on Dog Lake is registered with the Lake Partner Program, so no phosphorus or clarity record exists for the lake.

A Secchi disk is a white or black-and-white plate lowered on a marked line until it disappears from view. The depth at which it vanishes is the Secchi depth, a direct measure of water clarity. Clearer water gives a deeper reading.

See also Lake Water Quality and Blue-Green Algae in Ontario

Dog Lake Weather

The weather page for Dog Lake carries the forecast over the water, wave heights across the lake, and the modelled water temperature.

Dog Lake weather

Water temperature

Ontario’s aquatic resource records class Dog Lake as a cool-water lake, with a mean depth of 29.6 meters against its maximum of 100.

A lake separates into layers through the summer where it is deep enough. Sunlight and wind warm and mix the upper few meters, and beneath a band of rapid cooling, the thermocline, the water stays cold. A shallow lake mixes to the bottom instead and warms through, sooner in spring and later into autumn.

No provincial monitoring station records water temperature on Dog Lake. The LastLake model computes the temperature of its surface water for each day from the daily mean air temperature at Environment Canada’s Thunder Bay A climate station, 48 kilometers from the lake, or the next nearest station when its record is incomplete, and from the lake’s area of 14,592 hectares and its mean depth of 29.6 meters.

Each day’s figure carries the model’s typical error for that month on lakes of the same size. The figure in the chart below is the temperature near the surface, away from the shoreline. Bays, shallows and water deeper below the surface differ in temperature. Temperature is not measured when ice covers the lake. The weather page for Dog Lake carries the model’s figures for the past weeks and the coming week.

See also Lake Water Temperature in Ontario

Fish in Dog Lake

Ontario’s aquatic resource records name 14 fish species in Dog Lake. The province’s other records for the lake name two further species, lake trout and splake. They appear in the records below.

Popular species in the province’s records

  • Lake Whitefish, U.S. Fish and Wildlife ServiceLake Whitefishtrout and whitefish
  • Cisco, Painting by Ellen EdmonsonCiscotrout and whitefish
  • Northern Pike, Drawing by Timothy KneppNorthern Pikepike
  • Walleye, Raver Duane, U.S. Fish and Wildlife ServiceWalleyeperch
  • Yellow Perch, Raver Duane, U.S. Fish and Wildlife ServiceYellow Perchperch
  • Smallmouth Bass, Raver Duane, U.S. Fish and Wildlife ServiceSmallmouth Basssunfish
  • Burbot, USFWS Mountain-PrairieBurbotcod
Other species in the province’s records, with one observation the province could not identify
FamilySpecies
Trout and whitefishlake trout, splake
Suckerlongnose sucker, white sucker
Minnowspottail shiner
Sculpindeepwater sculpin
Trout-perchtrout-perch
Othersmelts, trout-perches

Stocking history

Ontario’s stocking records for Dog Lake run from 1999 to 2004 and hold 30 releases. Splake account for most of the fish: 246,293 released in six of the years between 1999 and 2004. The last recorded release was 24,313 splake yearlings in 2004.

Fish released into Dog Lake, 1999 to 2004
SpeciesYearsYears with a releaseFish released
Splake1999 to 20046246,293
Lake Trout1999 to 20035200,822

The province’s record of stocking for recreational fishing, kept from 2016, lists no release into Dog Lake.

Eating the fish

The 2026 Guide to Eating Ontario Fish carries consumption advice for seven species taken from Dog Lake, tested for contaminants at a sampling location northwest of Thunder Bay, Thunder Bay Dist. Each figure below is the most meals a month the guide advises for a fish of that length. Where mercury sets the advice, the figure falls as the fish gets longer, because mercury accumulates over a fish’s life. A zero means the guide advises no meals of that fish at that size.

General population: adultsSensitive population: children under fifteen, women who are or may become pregnant

Lake Whitefish Mercury
Length, cm40 to 4545 to 5050 to 55
General population161612
Sensitive population844
Walleye Mercury
Length, cm25 to 3030 to 3535 to 4040 to 4545 to 5050 to 5555 to 6060 to 6565 to 7070 to 75
General population12844220000
Sensitive population4400000000
Northern Pike Mercury
Length, cm20 to 2525 to 3030 to 3535 to 4040 to 4545 to 5050 to 5555 to 6060 to 6565 to 7070 to 75over 75
General population1616161288844442
Sensitive population884444000000
Smallmouth Bass Mercury
Length, cm25 to 3030 to 3535 to 4040 to 4545 to 50
General population88442
Sensitive population44000
Burbot Mercury
Length, cm40 to 4545 to 5050 to 55
General population844
Sensitive population000
White Sucker Mercury
Length, cm45 to 5050 to 5555 to 60
General population1688
Sensitive population440
Longnose Sucker Mercury
Length, cm45 to 5050 to 5555 to 60
General population844
Sensitive population400

Fisheries Management Zone 6

Dog Lake lies in Fisheries Management Zone 6. Ontario sets its fishing seasons and catch limits by zone.

Fisheries management zones around Dog Lake

245796Dog Lake
Zone 6 seasons / catch and keep daily limits, 2026
SpeciesOpen seasonSport licenceConservation licence
Atlantic SalmonOpen all year10
Brook Trout4th Sat. in Apr. – Labour Day5, not more than 1 greater than 30 cm (11.8 in.)2, not more than 1 greater than 30 cm (11.8 in.)
Brown TroutOpen all year52
Channel CatfishOpen all year126
CrappieOpen all year1510
Lake TroutJan. 1 – Sept. 302, not more than 1 greater than 56 cm (22 in.) from Sept. 1 – Sept. 30; no size limit rest of year1, no size limit
Lake WhitefishOpen all year126
Largemouth and Smallmouth Bass or any combinationOpen all year42
Muskellunge3rd Sat. in June – Dec. 151, must be greater than 91 cm (36 in.)0
Northern PikeOpen all year4, not more than 1 greater than or equal to 70 cm (27.6 in.)2, not more than 1 greater than or equal to 70 cm (27.6 in.)
Pacific SalmonOpen all year52
Rainbow TroutOpen all year10
SplakeOpen all year52
SunfishOpen all year5025
Walleye and Sauger or any combinationJan. 1 – Apr. 14 & 3rd Sat. in May – Dec. 314, not more than 1 greater than 46 cm (18.1 in.)2, not more than 1 greater than 46 cm (18.1 in.)
Yellow PerchOpen all year5025

Zone-wide, Smelt may not be used as bait or possessed for use as bait except where exceptions apply.

See also Fishing Seasons in Ontario, Zone by Zone and Fish Stocking in Ontario Lakes

Islands and names

Dog Lake contains 121 islands in the Ontario Hydro Network’s outline, twelve of them over 10 hectares and 36 under a tenth of a hectare. One of them lies mostly inside wetland the province’s Wetland With Significance dataset maps as marsh.

12345678910
The ten largest islands outside wetland mapped as marsh. Areas are measured on the province’s outline.
The ten largest islands outside wetland mapped as marsh
IslandHectares
1unnamed119.9
2Big Island57.2
3unnamed54.9
4unnamed52.9
5unnamed43.1
6unnamed34.3
7unnamed34.0
8unnamed16.5
9unnamed14.8
10unnamed14.1

Official names

Ontario’s geographic names register lists 10 official names on the water and its islands: 1 island and seven bays. A further 1 named point stands on the mainland shore.

Bays 7

  • Buda Bay
  • Creighton Bay
  • East Bay
  • Hawk Bay
  • North Bay
  • Stirrett Bay
  • Walberg Bay

Points on the shore 1

  • Bad Point

Nearby lakes

All lakes

Questions about Dog Lake

  • How deep is Dog Lake?

    Its deepest charted contour is 100 meters, and the water within it is deeper.

  • How big is Dog Lake?

    Its surface covers 145.9 square kilometers and it holds 121 islands. Of its 373 kilometers of shoreline, 294 kilometers is the mainland shore and 79 kilometers is the shore of the islands.

  • What fish are in Dog Lake?

    Ontario’s aquatic resource records name fourteen species, among them walleye, smallmouth bass, northern pike, lake whitefish and yellow perch. The lake’s spawning, consumption and stocking records also name lake trout and splake.

Lake guides

All lake guides

Looking at a property on Dog Lake?

Depth and water quality are two records out of many. Our Rural & Cottage Buyer’s Report gathers what the public record holds about one specific address: shore road allowance, road access, wells, flood mapping, Crown land, wetlands and more, read and checked by a person before it is sent.

See what is in the report

The cover page of a sample report

Where these figures come from

  • Depth, shoreline, islands and named places: Ontario Ministry of Natural Resources bathymetry and the Ontario Hydro Network, © King’s Printer for Ontario, Open Government Licence – Ontario.
  • Aerial photography: Ontario Imagery Web Map Service, © King’s Printer for Ontario, Open Government Licence – Ontario, drawing this frame from North Western Ontario Orthophotography Project 2022, Northwestern Ontario Orthophotography Project 2017, Forest Resource Inventory T2 (T2) 2018-2027, Forest Resources Inventory 2007-2011 and Sentinel 2 2025, satellite.
  • Official names: Geographic Names Ontario, Ministry of Natural Resources, Open Government Licence – Ontario.
  • Lake outline and municipal boundaries: Ontario Hydro Network and Ontario municipal boundary records, Ministry of Natural Resources, Open Government Licence – Ontario.
  • Surface water temperature: LastLake model, on the daily air temperatures of Environment and Climate Change Canada’s climate stations and its forecast. Data Source: Environment and Climate Change Canada.
  • Fish species and thermal regime: Ontario Aquatic Resource Area records. Spawning areas: Ontario Fish Activity Area records. Both Ministry of Natural Resources, Open Government Licence – Ontario.
  • Stocking: Historical Fish Stocking Data and Fish Stocking Data for Recreational Purposes, Ministry of Natural Resources, Open Government Licence – Ontario.
  • Consumption advice: Guide to Eating Ontario Fish advisory database, 2026 edition, Ministry of the Environment, Conservation and Parks, Open Government Licence – Ontario.
  • Seasons and limits: Ontario recreational fishing regulations data, Ministry of Natural Resources, Open Government Licence – Ontario.
  • Zone boundaries: Fisheries Management Zone, Ministry of Natural Resources, Open Government Licence – Ontario.
  • Fish plates: Duane Raver, U.S. Fish and Wildlife Service; Ellen Edmonson and Hugh Chrisp, New York State Conservation Department; Timothy Knepp, U.S. Fish and Wildlife Service; U.S. Fish and Wildlife Service. All public domain.