Solution

On the left path, let Matsya fish and search the rocks for bait.

Description

“I'd never felt a fish pull with such strength. At that moment, I swore on my pride as a fisher that I would not let this prize escape!”

Due to its tendency to absorb and accumulate toxins from its prey, the draco barracuda that Matsya returned with is not safe for consumption. To be clear, the fish's flesh is not inherently toxic, so a brave soul could perhaps eat one and live─and I am certain more than a few have done just that. I know several fellow alchemists who would sample a barracuda just to experience its potency for themselves, in fact. Fortunately, I found it listed within a compendium kept at the Great Work, so I knew there was nothing to be gained from such questionable endeavors.

The toxin of the draco barracuda can be used as an alchemical agent, much like the venom of the hamsa. The island's lush environment likely afforded this particular specimen plenty of prey to feast upon, and as a consequence I suspect it is highly toxic.

Kalika informed me that draco barracuda were revered by Aloalo's people because they kept harmful seaweed and poisonous smaller fish in check. If one was accidentally caught, it was given back to the sea as a gesture of gratitude. I cannot help but wonder whether Matsya should have done the same.