"Sholeh" is like lifting. Once [the width of] a Sela (a coin worth four Zuz) dried, even if it is still quivering, and while it was quivering he cast it back to the sea, he is liable for killing, which is an Av Melachah;

A Mishnah (Shabbos 73b) lists slaughtering and flaying among Avos Melachos.