Long Lake

Where Long Lake is

Long Lake lies in the District of Timiskaming, with shoreline in the Municipality of Charlton and Dack.

How deep is Long Lake?

Long Lake reaches a maximum recorded depth of 45.0 meters, determined from 78,940 soundings.

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.

Long Lake has 3 Lake Partner monitoring sites, none of which has yet reported phosphorus for the three years the province requires before a status is assigned.

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

Fish in Long Lake

Ontario’s aquatic resource records name 12 fish species in Long Lake. The province’s other records for the lake name one further species, lake sturgeon. It appears in the records below.

Popular species in the province’s records

• Lake Trouttrout and whitefish
• Lake Whitefishtrout and whitefish
• Ciscotrout and whitefish
• Northern Pikepike
• Walleyeperch
• Yellow Perchperch
• Smallmouth Basssunfish
• Rock Basssunfish
• Burbotcod
• Brown Bullheadcatfish
• Lake Sturgeonother

Spawning areas

Ontario maps 1 fish spawning record within the Long Lake outline: 1 lake trout spawning area covering 0.02 hectares. Every record is recorded as verified and presently suitable, and none is classed as sensitive.

By number of records

By area mapped

• Lake Trout1 area200 m²

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 Long Lake run from 2001 to 2015 and hold 16 releases. Lake Trout account for most of the fish: 59,917 released in twelve of the years between 2001 and 2015. The last recorded release was 50 lake trout adults in 2015.

Eating the fish

The 2026 Guide to Eating Ontario Fish carries consumption advice for six species taken from Long Lake, tested for contaminants at a sampling location in Kushog, Kinogami & Robillard Lakes, Timiskaming 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. Where the guide has no result yet for certain contaminants at a location, it sets a precautionary limit of 16 meals a month. 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

Fisheries Management Zone 8

Long Lake lies in Fisheries Management Zone 8. Ontario sets its fishing seasons and catch limits by zone.

Fisheries management zones around Long Lake

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

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

Islands and names

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

Official names

Ontario’s geographic names register lists 3 official names on the water and its islands: 1 island and one bay.

Bays 1

• McColl Bay

Nearby lakes

• Kenogami Lake29 km away
• Sesekinika Lake36 km away
• Larder Lake44 km away
• Mistinikon Lake47 km away

All lakes

Questions about Long Lake

• How deep is Long Lake?

  Its maximum recorded depth is 45 meters.

• How big is Long Lake?

  Its surface covers 9.7 square kilometers and it holds 4 islands. Of its 88 kilometers of shoreline, 86 kilometers is the mainland shore and 2 kilometers is the shore of the islands.

• What fish are in Long Lake?

  Ontario’s aquatic resource records name twelve 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 lake sturgeon.