Problem is that pressures are ridiculously different on the surface versus the deep ocean (it was someone’s really good idea to make the Thrive oceans max out at almost 6000 m deep). What makes it easier to adjust is just clicking the slider and then using the left and right arrow keys to adjust it.
I’ve opened an issue about improving the slider:
I don’t know what to say other than this was not promised.
So it is just gameplay variety from stuff evolving. Though, this shouldn’t be too common as it leads to people reporting it as a “bug”. So hopefully it isn’t too prevalent as I have no idea what would need to be adjusted to make this less likely to happen.
So it did affect them? Probably the external effects dropping the population due to deaths on screen would have been very massive.