Fish are planters, which DFG plants regularly. Well worth your time camping. Bears are generally regular nightly visitors. Since you no doubt have canvas sides, take precautions. Keep food in the fridge.
Bears can be a real pain.
They are also wild and dangerous if you are careless with food. Don't leave food between you and the bears. Check with the Forest Service on bear precautions and follow them. All Mammoth Lakes are popular. Fishing pressure is heavy.