If data and hypotheses suggesting future increases in sea level are correct, beach erosion will accelerate and put further pressure on seabeach amaranth. This amaranth has certainly survived other episodes of sea level rise, which have occurred naturally and episodically in the past. Pleistocene temperature fluctuations and variations in glaciation have resulted in major changes in geologically recent times in the position of the Carolina coast. Natural episodes of barrier island retreat have accommodated fugitive species such as seabeach amaranth. Even a rapid retreat is unlikely to have severely detrimental effects for seabeach amaranth, for in a natural landscape of barrier island retreat there are localized areas where islands are accreting, especially in the vicinity of inlets.
Inlets are never naturally stable and are always in flux.
Overwash is commoner along the mid-Atlantic coast than along the other sections. The mid-Atlantic section is close to the track that most of the winter northeasters follow as they move offshore, and the tide range is small. As a result high storm surges are frequent. At island ends, inlet migration generally means that land is accreting on one side of the inlet and eroding on the other. On the eroding side of the inlet, habitat for seabeach amaranth is usually small or absent.