Collecting Stone Tablet Writings

Find the [<S>111553|Stone Tablets] in the Broken Ruins and gather 15 [<S>203107|Stone Tablet Writings] for [111492|Nanbo Sathkur].

Those sneaky Weed-eating Fish! Now I finally understand why they would attack us as soon as we got close to those old ruins! It's because the [<S>111553|Stone Tablets] next to them contain important information regarding the whereabouts of the ancient treasure! Those greedy fish want the treasure all to themselves!

Junior Treasurehunt Squad Member No. 7, please go and gather 15 [<S>203107|Stone Tablet Writings] so we can conduct research on the whereabouts of the treasure.

This text is just some obscure puzzle, it hardly makes any sense.
No matter, this puzzle won't stop me - [111492|Nanbo Sathkur], Treasurehunter Extraordinaire!

It seems like we'll have to find a way to defeat those accursed Weed-eating Fish!