PARENT SESSION
PT8 - Chemistry & Toxicity of Sediments
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall

(P660) Acoustic mapping in support of contaminated sediment investigations.

Biberhofer, Johann^*,1, Rukavina, Norman¹, ¹ Environment Canada, Burlington, Ontario, Canada

ABSTRACT- Contaminant inventories in aquatic systems are often associated with deposits of muds and muddy sands. However, industrial waterfronts are often the results of shoreline modification, dredging and other engineering activities all of which can modify the expected distribution of the contaminated material. An acoustic seabed classification system (RoxAnn™) was used to map the distribution of river bottom substrates. The resulting maps were used to design a sediment sampling survey over a 2.5 km reach of the river, which focussed on the mud and muddy sand deposits. Priority areas for sampling were identified based on information on the size and location of the deposits. The sampling survey proved to representative of the reach as well as being much more efficient. The maps were also used to provide a context chemistry results attained from the survey as well as help describe spatial inconsistencies in contaminant concentration gradients.

Key words: acoustic mapping, sediments