Heh, Yknow, if the ARK's ecosystems were outta whack with too many predators, there would be too many predators released onto earth. Forget raptor overspawns, alpha t-rexes anyone? Anyways, a good question would be: Can the ARKS still generate creatures after their barriers are let down and the overseer chamber is activated? Also, with an orbital tilt or whatever, the snowy areas on ARKs such as the island's snow biome would melt, creating an excess of water, most likely leading to some sorta flood. (Cough, bible, Cough)
The ARKs landing on the top and bottom of the Earth would most likely keep their snow, however.