Actually i have been to moalboal twice already and enjoyed the sardines very much. i chatted with someone who worked at resort in moalboal a few months ago and they told me, the sardines were gone right now? i did not know they were seasonal and i had thought the sardines were always there? it was the first time i ever heard about the sardines coming and going in moalboal. i do also plan to go to oslob. i have snorkled with the butanging twice already in donsol on 2 different trips. i did want to scuba dive with them, if possible this coming august. i thought they just started feeding the butanging at oslob, and i was curious if they were still feeding them at oslob so that the butanding were still staying at oslob or not? so im just curious about things there before i come in august 2012.
I do not believe that it is a seasonal change, although if anybody else knows differently, please correct me, but apparently the sardines are no longer in Moalboal. I read somewhere on this board that they have reappeared in Mactan, although not in the same numbers that were present in Moalboal. Who knows though, perhaps they will return to Moalboal in August, it's impossible to predict.
I'm not sure if you've read anything on the whale sharks at Oslob, but there has been quite a lot of controversy. Just by browsing this board, you are sure to come up with multiple threads about the "circus", or "zoo", as it is commonly referred to. The local fishermen do feed them, and they are still there, but there are no rules or guidelines about snorkeling with them, touching them, or even the number of people that are allowed to be in the water with them at a certain time. I've read that many of the operators in Cebu and Dumaguete/Dauin are refusing to organize trips there until the locals clean up their act. As Hydreliox said, for the safety of the whale sharks, I would not go to Oslob and support the mistreatment of such graceful animals. It has been a huge boom for the local economy of Oslob, and of course the local operators and fishermen do not mean to mistreat the whale sharks, they just simply don't know any better.
Here are some pictures of the whale sharks in Oslob:
Also, read this blog post by Liquid Dumaguete, explaining some of their reasoning for discontinuing snorkeling trips to Oslob:
Whale Sharks in Oslob | Project AWARE
I hope you enjoy your travels this summer, and that diving in the Visayas meets your expectations.