Requirements: Tannery skill (or someone else to obtain the otter fur for you)
In Alaska go to 'Vast Gulf Waters and find an otter, kill it and then SKIN CORPSE.
Now go to 'The Docks in Macao' and ASK COMPARDORE SPICES.
He'll tell you how the Chinese want otter furs, and that he usually has spices to trade.
GIVE OTTER CHEN he will give you a bundle of some form of herb or spice.
Go to 'The Port of Callao' and GIVE BUNDLE ENRIQUE