The best source of information on the population status of Black Tern is the Breeding Bird Survey (BBS). Reliability of the BBS is considered high, as it samples a large proportion of the range and has high precision in its trend estimates. The national BBS trend shows a large long-term decrease in abundance relative to 1970, especially during the 1970s and 1980s, resulting in an 82% decline in numbers. Large declines have occurred in all Canadian Bird Conservation Regions with at least medium reliability in BBS trends, as much as 97% in the southern parts of Ontario and Quebec. The Marsh Monitoring Program only provides information about trends in southern Ontario and Quebec, and just since 1995 in Ontario and 2004 in Quebec, but also shows large declines of over 80% in both regions.

The goal for Black Tern is to increase the population to the level it was at in the early 1970s, based on the Breeding Bird Survey. Trend data show that Black Tern is far below its goal range and its population decline is ongoing. The trend will need to stabilize before the population can begin to rebound, and it is not realistic for the goal to be met by 2050. Based on analysis of the historical population loss and potential growth rates, the interim target is to reach 35% of the goal by 2050. Achieving this target, and ultimately reaching the national goal for this species, will require ambitious and long-term conservation action.