Sci-fi/Fantasy book about people shapeshifting into birds & fish only to forget they were human

[Samuel]

Years ago, sometime between 2002 & 2008, I read the Chinese translation of a Sci-fi or Fantasy book; considering its content, it might also be categoried into Mystery novels. Since Chinese translations usually come out slow, I guess the book itself could be quite old.

It's about a female protagonist working (?) in a submarine (?) sailing on an alien planet(?). She found that submerging into the seawater of the ocean they are staying at can transform people into fish, while climbing (?) the trees on a local island can transform people into birds. But the temporal shapeshifting both elates and confuses people, making them gradually forget who they originally were; ultimately, some became addicted to shapeshifting, and some people stayed permanently in their animal form, forever lost to the sea or the air.

A peculiar detail is that after someone turned into a bird and back into their human form, a feather would remain stuck on their skin, marking their shapeshifting experience and hinting at the partial irreversibility of the transformation.

I vaguely remember this book to be part of a series, all evolving around the adventures of the same protagonist. Her name *might* start with an E or I or even Y, but after all these years and across a language barrier, I'm not sure about it.

If you have any idea what this book might be, please do tell. I've been wishing to revisit the story for a long time :)

[Samuel]

I heard that it is acceptable to bump my thread every 30 days, so here I am :)

[Sue]

Could it be the 'Petaybee' series by Anne McCaffrey and Elizabeth Scarborough? The protagonist's name is Yanaba.https://www.fantasticfiction.com/m/an...

[Ayshe]

Powers That Be by Anne McCaffrey and Elizabeth Ann Scarborough; series page: https://www.goodreads.com/series/4039... - goodreads links for Sue's suggestion

[David]

bump

[Samuel]

Sue wrote: "Could it be the 'Petaybee' series by Anne McCaffrey and Elizabeth Scarborough? The protagonist's name is Yanaba.https://www.fantasticfiction.com/m/an..."

Thank you :) Although after reading the synopsis of the series, I'm afraid it isn't what I'm looking for...

[Samuel]

Ayshe wrote: "Powers That Be by Anne McCaffrey and Elizabeth Ann Scarborough; series page: https://www.goodreads.com/series/4039... - goodreads links for Sue's sug..."

Thanks for providing the link :)

[Lobstergirl, au gratin]

Samuel, are you still looking for this or did you find it?

[Samuel]

Lobstergirl wrote: "Samuel, are you still looking for this or did you find it?"

Hi, I checked out the links for Petaybee Series suggested by @Ayshe, but it doesn't seem to be what I seek. So I'm still looking for the book :)