Evaluation of Underwater Contamination by Explosives and Metals at Point Amour Labrador and in the Halifax Harbour Area.

摘要

The intense maritime military activities, such as live fire training, capabilities assessment or even war, can incur damage to the environment. Numerous ships have sunk through the years in Canada's territorial waters. The ammunition stock that sank with them is likely to liberate contaminants in the aquatic environment. In this context, two separate studies were conducted, with the objective of collecting water and sediments samples in order to detect potential contamination by explosives or heavy metals. The first study was conducted at Point Amour, Labrador, where HMS Raleigh ran aground in 1922. Unexploded ordnances were present and in situ detonation was performed. Divers performed sampling before and after each detonation, along with a control site. The second study was conducted in the Halifax Harbour area, where two shipwrecks and one ammunition dumping area were considered. For this study, water and sediments sampling were performed, using a remote operation vehicle (ROV) at various spots in order to find contamination. For the Raleigh operation, trace levels of explosives were detected after detonation events. In the Halifax study, analyses showed no contamination by EM, but some high levels of metals, such as lead, were detected in sediments samples. Those two studies have demonstrated the importance of significant factors, such as sample manipulation and identification, weather conditions and sampling methods in deep water.