Bottom sediment sampling

Abstract

Tests with sampling equipment during 1967 and 1968 in Lake Ontario showed that some of the bottom samples were badly disturbed. As a result of these tests, further extensive trials of bottom-sampling equipment were conducted in Georgian Bay in 1968. These were designed to test the disturbance of the bottom sediments caused by ship movement and to test the efficiency and suitability of various types of sampling devices. It was found that under typical sampling conditions, bottom disturbance was induced by the ship when the total water depth was less than about 6 m. Also it was found that the ship, during typical sampling procedures in deeper water, induces disturbance in the water column, beneath it, to a depth of at least 14 m. Tests were conducted with 3 types of Gravity corer, 2 multiple corers, and 6 Grab samplers. These tests were designed to show their usefulness for both biological and geological sampling. All 3 gravity corers proved efficient for particular tasks. The most successful bottom grab samplers were found to be the Ponar grab and the Shipek bucket sampler.