The National Film Board has a new streaming video website to which they've posted many NFB films from over the decades.
You can search by category. For example, under "environment", I found this 1975 salmon migration and spawning documentary.
You can also search by keyword, and a few that I found useful as a streamkeeper are "salmon," "fish," "fishing," and "fisheries."
Once you're watching a film, lists of related films pop up.
Very cool! Potentially hugely time-wasting, er, I mean educational.
Yikes! As I watch the above salmon movie, it's bringing up issues that we're still nattering about nearly 35 years later...
You could spend hours deconstructing these films. For example, in the 1949 film Red Runs the Fraser, there was no mention that the slides that blocked fish passage in the Fraser River at Hell's Gate were caused by railway construction.