You can look at the words in front and behind it, because they refer to this big word. You may find a synonym of the word or a close reference. So for example in this sentence: I was excited and ambitious to learn about cars today. So this is a easy example. You can use exited to define ambitious if you dont know what ambitious means.
Answer: Based on its girth and size.
Explanation: According to the U.S. Fish and Wildlife Service, the lake sturgeon which is currently an endangered species can live up to 55years for males and 70 to 100years for females.
However, the size and girth is an important criteria used by fish experts in deducing the number of years a sturgeon had used.
Thus, the caught sturgeon is about 7feet long and along with its girth suggested it had spent over a century roaming in the water body.
I feel it is a horrid thing and absolutely messed up. It should never ever have been used or addressed as something allowed to happen. Also it was very racist obviously. It shouldn't happen ever again.