Toolik Lake is a kettle lake, which means it was formed by the melting of large blocks of buried glacier ice. It is 1.5km2 and at its deepest it is 25 meters.

Two Food Webs

BenthicBenthic organisms live on or in the bottom sediments of a sea or lake.

The benthic zone is the lowest level of a body of water. In Toolik lake, diatoms, or photosynthetic algae, and organic matter that falls from the water column is where it all begins. These are the food source for other organisms like snails and midge larvae which are then eaten by slimy sculpin, grayling and young lake trout. The adult trout eat smaller fish and snails.

Water ColumnHypothetical 'cylinder' of water between the surface of the ocean and the ocean bottom.

The main food source here is photosynthetic flagellates and bacteria that feed on organic molecules. They are not very productive, so there is only a sparse population of zooplankton. This causes the fish of Toolik lake to seek food from the lake's bottom.

We had a storm come through the field station and it cleared in the evening. Watch the clouds roll over the lake and disappear in this video!

Fly Your Flag in the Arctic

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Source: Land of Extremes: A Natural History of the Arctic North Slope of Alaska by Alex Huryn and John Hobbie