My plan this year is to fish Consultation and UBSL and not bother with the mountain since I have already done that, but there are no longer any walk up permits so I may not get to those lakes after all. Funny how almost everyone on that trail is there exclusively to summit Whitney with no other purpose but that. All the lakes that have fish are as a result of stocking but the conditions are such that they continue to spawn and thrive, They don’t have the same fishing pressures as other lakes to in the eastern sierra but I suspect there was a time in the distant past when more fishermen visited the area than just mountain climbers. With all the huppla to summit the tallest mountain in the lower 48, the fishermen have gone elsewhere, but I’m still interested and trying to dial in the on-line reservation site so I can score an overnight ticket on the main trail or the north fork.
On all my trips on the trails up MWMT and North Fork of LPC I've seen people who are there to just visit one of the lakes to boat or fish and have no plans to go further. I've seen a couple carry a plastic kayak up the E-ledges to visit LBSL. There have even been two guys who have scuba dived Lake Tulainyo -- although I did not see that in person.
Also, it's my understanding that walk-in permits to trails other than MWMT are still available.