Figure 2. Impact of Sea Level Rise on a Marsh. Coastal wetlands have kept pace with the slow rate of sea level rise that has characterized the last several thousand years. Thus, the area of wetlands increased as new lands were inundated. If in the future sea level rises faster than the ability of te wetlands to keep pace, the wetland area will decline. Construction of bulkheads, dikes, and the artificial elevation of nearby developed lands would prevent new wetlands from forming inland, resulting in a total loss in some areas. Source: Titus (1986). Why Will We Lose Marshes?