I can see some issues with this study's conclusions.
Well, of course, the students with a better performance in math will generally do better in the sciences in college. Most college courses are taught from a quantitative standpoint. In contrast, in most high schools, Biology, Earth Science, and Environmental Science are structured so math skills are relatively unimportant.
An example: last week, I was talking to my Physical Science class about graphs. I pointed out that a certain curved line would indicate exponential growth. Then I said, "But, I'm sure that you've all seen these kind of graphs in Biology". I was dumbfounded to hear that they never used graphs in Biology.
Now, perhaps that's an example of the well-known selective memory of students - 2 months after a class, most are hard put to name one thing they learned or a lab they performed. But, it's also possible that their teacher, like many Bio teachers, doesn't dwell on use of graphs.
