Longpine Lake

Where Longpine Lake is

Longpine Lake lies in the District of Kenora.

How deep is Longpine Lake?

The deepest mapped contour on Longpine Lake is 6.1 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 3 depth contours for Longpine Lake.

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.

Longpine Lake has 4 Lake Partner monitoring sites. Four have reported phosphorus for the three or more years the province requires before a status is assigned. One of those sites is classified oligotrophic and three mesotrophic.

The longest record is held by site 7154/1 at Main Basin-deep spot, with phosphorus sampled once a year over 19 years to 2025. Its long-term mean phosphorus concentration is 11.64 micrograms per litre, within the mesotrophic band, which runs from 10 to 20.

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.

The 136 clarity readings at site 7154/1 give a median Secchi depth of 2.5 meters.

Median Secchi depth by year at site 7154/1

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

Fish in Longpine Lake

Ontario’s aquatic resource records name 9 fish species in Longpine Lake.

Popular species in the province’s records

• Northern Pikepike
• Walleyeperch
• Yellow Perchperch
• Smallmouth Basssunfish

Spawning areas

Ontario maps 4 fish spawning records within the Longpine Lake outline: 4 walleye spawning areas covering 0.45 hectares.

By number of records

By area mapped

• Walleye4 areas0.5 ha

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 Longpine Lake run from 1947 to 1961 and hold 6 releases. Walleye account for most of the fish: 2,650,000 released in six of the years between 1947 and 1961. The last recorded release was 250,000 walleye eggs in 1961.

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

Fisheries Management Zone 5

Longpine Lake lies in Fisheries Management Zone 5. Ontario sets its fishing seasons and catch limits by zone.

Fisheries management zones around Longpine Lake

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

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

Islands and names

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

Nearby lakes

• Malachi Lake14 km away
• Lake Lulu30 km away
• Black Sturgeon Lakes49 km away
• Lake of the Woods70 km away

All lakes

Questions about Longpine Lake

• How deep is Longpine Lake?

  Its deepest charted contour is 6.1 meters, and the water within it is deeper.

• How big is Longpine Lake?

  Its surface covers 1.9 square kilometers and it holds 4 islands. Of its 23 kilometers of shoreline, 22 kilometers is the mainland shore and 1 kilometer is the shore of the islands.

• What fish are in Longpine Lake?

  Ontario’s aquatic resource records name nine species, among them walleye, smallmouth bass, northern pike and yellow perch.