Bioindicator and fish health studies around the Terra Nova oil development site on the Grand Banks

Bioindicators or health effect indicators can be a valuable reconnaissance tool for addressing concerns on the part of the fishing industry and public interests regarding any potential impacts of pollutants on fish stocks. American plaice (Hippoglossoides platessoides) was initially chosen by the oil industry as an indicator species for Environmental Effects Monitoring (EEM) programs in the Grand Banks of Newfoundland because it is an important commercial flatfish. This presentation reported on fish health studies carried out at the Terra Nova development site before and after release of produced waters, which began in 2003. These studies represented 1 component of the overall Terra Nova EEM program. Fish were collected near the development area and in a reference area 20 km away. A broad range of health effect indicators were studied, including fish condition, visible skin and organ lesions, levels of mixed-function oxygenase (MFO) enzymes, haematology and an array of 19 histopathological indices in liver and gills. These indicators have been widely used in laboratory and field investigations with various fish species. A slight elevation of MFO enzyme activity was observed in fish from the development area in 2002, before release of produced water. In 2006, other indices were similar between the development and reference area. It was concluded that the overall results do not indicate any project effects.