Last night I discovered there is a source of Chinese fish sauce other than in Chaoshan as mentioned above.
A short distance east of Chaozhou is Fujian province, which has also had an influence on Chaoshan's Teochow cuisine. But it seems the traffic hasn't all been one way. There is a Fujianese fish sauce.
S:闽江鱼露; T: 閩江魚露 (mǐn jiāng yú lù), Min River Fish Sauce is made in Fuzhou, the capital of Fujian. Fujian cuisine is know in China as 闽菜 (mǐn cài), after the river.
To be tried.