Exploration activity in Canada's east coast offshore region declined dramatically in 1989. Just 2 wells were completed during the year, both located in the Newfoundland offshore, 1 of which resulted in a new significant discovery of natural gas and oil. As a result of this discovery and revisions of previous estimates, the best current estimate of discovered resources in the east coast offshore is 258.9 million m³ (1.6 billion bbl) of oil and condensate, and 313.4 billion m³ (11 tcf) of gas.

Eight new exploration licenses were issued in 1989, divided between the Sable Island area and the Jeanne d'Arc basin offshore Newfoundland, suggesting a possible increase in activity in the next 3-4 years. Lasmo announced plans in 1989 to develop the Cohasset and Panuke light oil pools west of Sable Island. It is hoped that production can begin in 1992.

The Canada-Nova Scotia Offshore Petroleum Board was established in early 1990 following proclamation of the Canada-Nova Scotia Offshore Petroleum Resources Accord Implementation Act. The board is responsible for regulation and management of all Nova Scotia offshore petroleum activities.

Activity in Ontario decreased significantly in 1989 with drilling completed at a total of only 100 wells. The decrease is attributed to the termination of CEDIP, and to low oil and gas prices received by Ontario producers during 1988. Drilling of Ordovician targets, however, decreased only marginally from 1988 and dominated activity in the province, accounting for nearly half of all exploratory and development drilling in 1989. Drilling of Ordovician targets resulted in 14 new oil producers, including 1 new-pool discovery. New production from recently developed Ordovician reservoirs resulted in a 29% increase in annual oil production in Ontario in 1989. Production totaled approximately 244,000 m³ (1.5 million bbl), a new record for annual oil production in Ontario. he previous record was established in 1966.

There was a large increase in geophysical exploration and area held under oil and gas licenses and leases in Quebec in 1989. Several companies were active in the province.