The ability of tardigrades to resist unfavorable environmental
conditions particularly allied with parthenogenetic reproduction
makes the tardigrades very potent primary colonizers. If a
food source is available and conditions favorable for a period of
time, then the tardigrades can survive. They have been found on
nunataks—isolated rocky out crops—in Antarctica that are set
in a 500–1500 m deep ice sheet and separated from their nearest
neighbors by 20–150 km. New islands emerging from the sea are
rapidly colonized, with tardigrades arriving among the earliest.
Artificial structures are similarly very rapidly colonized.