Talk:FGO 2016 Summer Event/@comment-118.96.154.70-20160828155147/@comment-10691202-20160828190128

Seashells are also used for some skills upgrades (not just for ascension), which adds up significantly to total seashells ever needed (rough estimates, at least 100-200+ needed, should you ever have all those servants and want to level those skills up). Example: Squirtoria need 45 for all 3 skills to be upgraded. As such, it is unlikely they will just limit the seashells for this event only.

It is also possible some future servants may need it (maybe water-related servants?), though this purely speculation on my part.

I think someone has also posted before that DW has stated that the seashells will be available later, although it is currently unknown whether in future events or easily farmable in dailies/free quests, etc later on.