Temporal changes in Chinese mitten crab geographic expansion and increases in abundance. Black lines indicate the number of events per year, while the colored areas represent the same data collated by decade. A: The number of new regional records that were observed globally. Populations not established in the long-term either did not become established at all, or went locally extinct after a short boom phase; B: The number of observed regional increases in abundance. Autocorrelated increases are observed in a population that had been present in a region for less than ten years prior to the increase.