They do population and size samples but not with a trawl samples study. I don't think the areas of the lake that young smallmouth inhabit is condusive to trawl samples. The trawl samples for walleye are very disciplined, same areas, sames times of year, same duration and then count the young of the year and compare yearly results.
The smallmouth sampling I am familiar with, what I have seen, is conducted with nets in the fall and it is a collection method that kills the smallmouth and a data collection of age and size is performed on the collected dead fish. I don't think they have any other method to collect the data for smallmouth other than angler creel surveys that are active along the lake every year. I know that there was a smallmouth sampling net really close to one of my favorite smallmouth fishing locations near Vermilion for a couple of years. I haven't spoken with Travis in a couple of years I will call him and find out the status of the smallmouth from their studies. I will say that a few years ago I noticed a absence of young smallmouth in the areas of the lake I was fishing and discussed this with him at the time. Everything we would catch in a day, 50 +, would be from 3-6lbs, no smaller fish ever caught. Yet go around the islands and Pelee and there were small fish in abundance. I fished the same area again this year for the first time in a couple of years and again no small fish, just larger ones.