As a limnologist, you're going to be doing a lot of research, and it can be slow and time-consuming. You may end up finding a new species of plant life or animal life or even a new body of water that is clearer than any body of water anywhere in the world.
Or you may not. (The laws of chance dictate you won't.)
You may just toil in the water and soil, collecting samples, writing reports, inspecting various elements of the water and the animals it feeds and never really find fame at all.
But your family will be so proud. You're one of the few who does what she loves, makes a living at it, and is a happy person. That is something that should be famous: happiness in work, family, and life in general.