Manitoulin District, Ontario

Lake Manitou

Twenty-five islands and a charted depth of 48.8 meters, from a survey the province records without a year, across 106 square kilometers on Manitoulin Island. Lake trout water, stocked by the province five times between 2016 and 2024.

Surface: 106.5 km²
Shoreline: 120 km113 mainland + 7 islands
Islands: 25
Charted depth: 48.8 m
Depth contours: 122

All figures are derived from Ontario’s survey records.

Where Lake Manitou is

Lake Manitou lies in the District of Manitoulin, with shoreline in the Township of Assiginack, the Township of Billings, the Municipality of Central Manitoulin and the Town of Northeastern Manitoulin and the Islands.

How deep is Lake Manitou?

The deepest mapped contour on Lake Manitou is 48.8 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 122 depth contours for Lake Manitou.

The deepest charted contour on Lake Manitou, 48.8 meters. The circle marks the centre of that contour, and the water within it is deeper. The survey’s 122 depth contours are drawn where the province published them, and along the outline where the survey placed them beyond it. Outline from the Ontario Hydro Network. Each contour is labelled with its depth in meters; zoom in where they run close.

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 a water sample each spring for phosphorus analysis and measure water clarity through the summer with a Secchi disk.

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 spring phosphorus. Below 10 micrograms per litre is oligotrophic: clear water and low algae. From 10 to 20 is mesotrophic: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom. Above 20 is eutrophic: nutrient-rich water, prone to algal blooms and low oxygen at depth.

A Secchi disk is a 20 centimeter 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.

Lake Manitou has 11 Lake Partner monitoring sites. Two have reported phosphorus for the three or more years the province requires before a status is assigned. All are classified oligotrophic.

Lake Partner sites on Lake Manitou with a quotable phosphorus record
Site	Location	Years	Last sampled	Classification
6451/4	Stn4 E Sandfield Bay	23	2025	oligotrophic
6451/10	MANI3 – Green Bay 3	4	2025	oligotrophic

The longest record is held by site 6451/4 at Stn4 E Sandfield Bay, sampled over 23 springs to 2025. Its long-term mean phosphorus concentration is 7.41 micrograms per litre, within the oligotrophic band, which extends to 10. The site’s 151 clarity readings give a median Secchi depth of 6.0 meters.

Median Secchi depth by year at site 6451/4, surface at the top. The thin line through each bar spans the shallowest and deepest reading that year, and the row beneath the years gives the number of readings. Years without readings are blank.

Fish in Lake Manitou

Ontario’s aquatic resource records name 31 fish species in Lake Manitou. The province classes the lake as cold water. The record took effect on 27 September 2021, and it compiles what field biologists had reported by then. The province’s other records for the lake name one further species, rainbow trout. It appears in the records below.

Thirteen of the 32 species in the province’s records

Lake Trouttrout and whitefish
Brook Trouttrout and whitefish
Rainbow Trouttrout and whitefish
Lake Whitefishtrout and whitefish
Ciscotrout and whitefish
Northern Pikepike
Walleyeperch
Yellow Perchperch
Smallmouth Basssunfish
Rock Basssunfish
Pumpkinseedsunfish
Burbotcod
Brown Bullheadcatfish

The other nineteen species in the province’s records
Family	Species
Trout and whitefish	splake
Perch	iowa darter, johnny darter, logperch
Sucker	white sucker
Smelt	rainbow smelt
Minnow	bluntnose minnow, common shiner, creek chub, emerald shiner, fathead minnow, lake chub, mimic shiner, spottail shiner
Sculpin	mottled sculpin, slimy sculpin, spoonhead sculpin
Trout-perch	trout-perch
Other	trout-perches

Spawning areas

Ontario maps 2 fish spawning records within the Lake Manitou outline: 2 northern pike spawning areas covering 8.2 hectares.

By number of records

By area mapped

Northern Pike2 areas8.2 ha

Spawning records mapped by the province within the Lake Manitou outline. A record under 100 square meters is drawn as a dot; a spawning area is drawn as the outline mapped. One colour per species, the same as the bars and the list above.

The federal Fisheries Act prohibits the harmful alteration, disruption or destruction of fish habitat without an authorization, so a dock, dredging, infill or shoreline work at a mapped spawning area is reviewed on that basis.

Stocking history

Ontario’s stocking records for Lake Manitou run from 1946 to 2015 and hold 283 releases. Lake Trout account for most of the fish: 2,755,578 released in 60 of the years between 1947 and 2015. The last recorded release was 9,280 lake trout yearlings in 2015.

Fish released into Lake Manitou, 1946 to 2015
Species	Years	Years with a release	Fish released
Lake Trout	1947 to 2015	60	2,755,578
Smallmouth Bass	1946 to 1987	30	317,700
Brook Trout	1964 to 2015	11	73,768

The province’s current stocking programme, recorded from 2016, lists 291,986 lake trout released into Lake Manitou between 2016 and 2024.

Eating the fish

The 2025 Guide to Eating Ontario Fish carries consumption advice for nine species taken from Lake Manitou, tested for contaminants at a sampling location in Sandfield Twp., Manitoulin Dist. Each figure below is the most meals a month the guide advises for a fish of that length. The advice 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 Trout PCB
Length, cm	30 to 35	35 to 40	40 to 45	45 to 50	50 to 55	55 to 60	60 to 65	65 to 70	70 to 75	over 75
General population	32	32	16	16	16	12	8	4	4	2
Sensitive population	32	32	16	16	12	8	8	4	4	0

Lake Whitefish PCB, Selenium
Length, cm	45 to 50	50 to 55	55 to 60	60 to 65
General population	16	16	16	16
Sensitive population	16	16	16	16

Walleye Mercury
Length, cm	30 to 35	35 to 40	40 to 45	45 to 50	50 to 55	55 to 60	60 to 65	65 to 70	70 to 75	over 75
General population	32	32	32	32	32	16	8	4	4	2
Sensitive population	32	16	16	16	12	8	4	0	0	0

Northern Pike Mercury
Length, cm	55 to 60	60 to 65	65 to 70	70 to 75	over 75
General population	32	16	16	16	12
Sensitive population	12	12	8	8	4

Smallmouth Bass Mercury, Selenium
Length, cm	20 to 25	25 to 30	30 to 35	35 to 40	40 to 45	45 to 50	50 to 55
General population	16	16	16	16	16	8	8
Sensitive population	16	16	16	16	8	4	4

Yellow Perch Mercury, Selenium
Length, cm	25 to 30	30 to 35
General population	16	16
Sensitive population	16	8

Burbot Mercury
Length, cm	35 to 40	40 to 45	45 to 50	50 to 55	55 to 60	60 to 65	65 to 70	70 to 75	over 75
General population	32	32	16	16	16	16	12	8	4
Sensitive population	32	16	8	8	4	4	4	4	0

Brook Trout PCB
Length, cm	15 to 20	20 to 25	25 to 30	30 to 35	35 to 40	40 to 45	45 to 50	50 to 55	55 to 60
General population	32	32	16	16	16	16	16	12	12
Sensitive population	32	32	16	16	16	16	12	12	8

Rainbow Smelt PFAS
Length, cm	15 to 20
General population	8
Sensitive population	8

Fisheries Management Zone 10

Lake Manitou lies in Fisheries Management Zone 10. Ontario sets its fishing seasons and catch limits by zone.

Zone 10 seasons and limits, 2026
Species	Open season	Sport licence	Conservation licence
Atlantic Salmon	Jan. 1 – Sept. 30	1	0
Brook Trout	Jan. 1 – Sept. 30	5	2
Brown Trout	Open all year	5	2
Channel Catfish	Open all year	12	6
Crappie	Open all year	30	10
Lake Trout	Jan. 1 – Labour Day	2, not more than 1 greater than 40 cm (15.7 in.)	1
Lake Whitefish	Open all year	12	6
Largemouth and Smallmouth Bass or any combination	3rd Saturday in June – November 30	6	3
Muskellunge	3rd Sat. in June – Dec. 15	1, must be greater than 122 cm (48 in.)	0
Northern Pike	Open all year	6; not more than 1 greater than 61 cm, none greater than 86 cm	2; none greater than 61 cm
Pacific Salmon	Open all year	5	2
Rainbow Trout	Open all year	2	1
Splake	Open all year	5	2
Sunfish	Open all year	50	25
Walleye and Sauger or any combination	January 1 to the third Sunday in March and third Saturday in May to December 31	4, none greater than 46 cm	2, none greater than 46 cm
Yellow Perch	Open all year	50	25

The figures are the number of fish an angler may catch and keep in a day and have in possession, under a sport fishing licence and under a conservation licence. The rows are the whole zone’s, and they apply to every lake in it.

Exceptions for Lake Manitou itself, 2026
Species	Open season	Sport licence	Conservation licence
Lake Trout	Jan. 1 – Sept. 30	2, no size limit	1, no size limit
Rainbow Trout	4th Sat. in Apr. – Dec. 31	Zone-wide	Zone-wide
Yellow Perch	Jan. 1 – Mar. 31 & 3rd Sat. in May – Dec. 31	50; 25 in one day	12 in one day; 25
Northern Pike	Jan. 1 – Mar. 31 & 3rd Sat. in May – Dec. 31	Zone-wide	Zone-wide

Where a row reads zone-wide, the zone’s own season or limit above applies.

Lake Manitou Ice Fishing

An ice hut on Lake Manitou must be removed by March 31. Lake Manitou lies in fisheries management zone 10, one of the twenty zones Ontario sets its fishing rules by, and one removal date applies across the whole zone.

An ice hut must also be removed before the ice breaks up, whether or not that date has passed. The deadline clears huts from the ice ahead of the thaw and does not close the fishing season.

Registration is required in zone 10 for an ice hut built of anything other than fabric, and for a fabric tent covering seven square meters or more. Registration is free, and the number is displayed on the outside of the hut.

Ice conditions

No public record reports the thickness or the condition of the ice on Lake Manitou on any given day. Ontario publishes ice safety guidance for anyone going out on the ice, at ontario.ca.

Islands and names

Lake Manitou contains 25 islands in the Ontario Hydro Network’s outline, zero of them over 10 hectares and fourteen under a tenth of a hectare.

The ten largest islands, numbered to the table. Areas are measured on the province’s outline.

The ten largest islands
	Island	Hectares
1	Roper Island	2.8
2	McCracken's Island	2.2
3	Bear Island	1.5
4	unnamed	0.6
5	Big Gooseberry Island	0.6
6	Tree's Island	0.6
7	Bass Island	0.3
8	Battleship Island	0.2
9	unnamed	0.1
10	Little Gooseberry Island	0.1

Official names

Ontario’s geographic names register lists 59 official names on the water and its islands: 13 islands, 30 bays, two shoals, one rock, one narrows and nine points on islands. A further 11 named points stand on the mainland shore.

Bays 30

Bass Bay
Bass Creek Bay
Bathouse Bay
Ben's Bay
Bragmore Bay
Cannard's Bay
Cape Horn Bay
Dawes Bay
Dick's Bay
Eagle's Nest Bay
Gibraltar Bay
Green Bay
Jump's Bay
Kotcamp's Bay
Martin's Bay
Moody Bay
Newby's Bay
Sandfield Bay
Sandy Bay
Schut's Bay
Shearpin Bay
Shirley's Bay
Sidney Cox Bay
Silver Bay
Surecatch Bay
Tilson's Bay
Timberlane Bay
Turtle Creek Bay
Watson Bay
Wee Point Bay

Shoals and rocks 3

Acre Shoal
Copper Rock
Roper's Shoal

Harbours, cuts and narrows 1

The Narrows

Points on the shore 11

Brennan's Point
Cape Horn Point
Clark's Point
Grable's Point
King's Point
Lone Star Point
Long Point
Maple Point
Maple Rock Point
Paul's Point
Watson Point

Nearby lakes

Mindemoya Lake17 km away
Lake Kagawong25 km away
Lake Wolsey42 km away
Agnew Lake67 km away

All lakes

Questions about Lake Manitou

How deep is Lake Manitou?
Its deepest charted contour is 48.8 meters, and the water within it is deeper.
How big is Lake Manitou?
Its surface covers 106.5 square kilometers and it holds 25 islands. Of its 120 kilometers of shoreline, 113 kilometers is the mainland shore and 7 kilometers is the shore of the islands.
What fish are in Lake Manitou?
Ontario’s aquatic resource records name 31 species, among them lake trout, walleye, smallmouth bass, northern pike, lake whitefish and yellow perch. The lake’s spawning, consumption and stocking records also name rainbow trout.
Is the water clear?
All two monitoring sites with a phosphorus status are classified oligotrophic, the clearest of the province’s three bands.

A print of Lake Manitou

Lake Manitou has not yet been drawn as a print. The lakes drawn so far are on the lake maps page, and a print of Lake Manitou can be requested by email; whether it can be drawn is confirmed before any payment.

Ask about a Lake Manitou print

Looking at a property on Lake Manitou?

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

What these figures do and do not say

Depth: A depth reading is the distance from the water surface on the day of survey to the lake bottom. Lake levels vary through the season and between years. The depth figure above is the deepest contour charted and is a minimum; the depth within it was not recorded. The figures for Lake Manitou are read from the province’s bathymetry records within the Ontario Hydro Network’s outline of the lake: the deepest figure is the deepest record inside that outline, and the count is every record inside it.
Shoreline and surface: The shoreline figure is the length of the mainland shore and of every island shore added together, measured on the Ontario Hydro Network’s outline of the lake. The surface figure is the area of water inside that outline, less the area of its islands. The provincial outline is mapped to within a few meters of the shore, and a shoreline measured from a coarser map comes out shorter, which is why a figure published elsewhere is often lower.
Survey coverage: Not every survey covered every arm of a lake, and the province’s index does not always record where a survey ended.
Water quality: Each figure belongs to a single monitoring site and not to the lake as a whole. A bay receiving a creek can read differently from open water half a kilometer away. Sites are matched to Lake Manitou by name in the province’s records.
Nearby lakes: Distances are measured between lake centres.
Islands and names: Islands are counted and measured on the Ontario Hydro Network outline; names are the register’s, placed by its own coordinate. The register names islands the outline draws as part of a larger one, and the outline holds islands the register has not named, so the two counts differ. The outline carries some lakes across marsh, so a gap in the marsh is drawn as land, and every such gap is included in the island count. Where the register has not named one and it lies mostly inside a wetland in the province’s Wetland With Significance dataset, the page names the wetland and the table of largest islands leaves it out. Wetland boundaries are mapped at their own scale and can cover a small island whole.
Depth contours: Each contour is drawn where the survey placed it, at the survey’s own positional accuracy. The survey carries its own shoreline, which differs from the Ontario Hydro Network’s outline, so a contour near the shore can run to or past the outline. Such a stretch is drawn along the outline, as a drawing convention, and is not the survey’s line there. The contour count in the stat band is the province’s, and it includes the survey’s own shoreline contour, one ring around the mainland and one around each charted island, which the map leaves off; the map’s small print gives the split.
Location: Municipal boundaries are read from the province’s records as published and can lag a boundary change.
Fish: Ontario’s fish records are compilations of existing knowledge from field biologists and do not represent exhaustive inventories. A species that is not listed was not ruled out. The species list carries one date for the whole record and none for any species.
Spawning areas: A spawning area is drawn where the province mapped it, at the province’s stated accuracy, and the record says nothing about how many fish use it in a given year. A nest record is one nest seen on one day; a count of nests is not a count of fish, and a count of records is not a comparison between species. Whether a given piece of work needs an authorization is a determination made by Fisheries and Oceans Canada on the work itself.
Stocking: A stocking record is a release on a date. It says nothing about how many fish survived or about the population in the lake today.
Eating advice: The guide’s advice is for fish taken from the lake at the tested location and applies to the size classes tested. The province’s guide is the authority and is updated each year.
Fishing rules: Seasons and limits are the zone’s, for the year of the dataset the page was built from, and a licence’s own conditions and any waterbody exception apply over them. The province’s regulations summary is the authority.
Ice hut rules: Removal dates and registration rules are set by fisheries management zone and change from time to time. The dates here were read from the province in September 2026. The province’s own fishing regulations are the authority.

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.
Phosphorus and water clarity: Ontario Lake Partner Program, Ministry of the Environment, Conservation and Parks, Open Government Licence – Ontario. Extract built 2026-08-09.
Aerial photography: Geospatial Ontario imagery, Open Government Licence – Ontario, released collections only.
Official names: Geographic Names Ontario, Ministry of Natural Resources, Open Government Licence – Ontario. Marinas: Overture Maps Foundation places data, CDLA-Permissive 2.0.
Lake outline and municipal boundaries: Ontario Hydro Network and Ontario municipal boundary records, Ministry of Natural Resources, Open Government Licence – Ontario.
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, 2025 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.
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.
Ice hut removal dates and registration: Ontario fishing regulations, read September 2026.