You could hear the roars of some type of Leviathan in the area, presumably a Chelicerate. You knew there were a couple Juvenile Vent Garden, and of course the adult one, but they didn't pose a threat. If anything the adult provided some shelter. Though you did know there were other dangers... such as the two Chelicerate Leviathans that somehow haven't noticed you yet

"GRAAAAAAAW!!"

A piercing screech was dangerously close by as you turned around. You probably shouldn't have jinxed it.

A Chelicerate Leviathan was swimming after you, its mandibles open wide ready to swallow you whole. And you didn't feel like dying to an oversized shrimp with no legs.