Where streams & rivers meet the sea
Estuaries are the depositional surfaces where freshwater streams and rivers meet the sea. This category and its first 2 sub-categories consider the intertidal portions of these habitats. The 3rd sub-category addresses the adjoining supratidal meadows, shrub thickets, and young spruce forests that are especially common in the north where glacial rebound is occurring.
Mapping estuaries over a large region like Southeast Alaska is a classic exercise in landscape ecology. This requires dependence on huge spatial databases that may or may not be founded on ecological realities. In our work with freshwater wetlands, we’ve found the National Wetlands Inventory (NWI) to be of limited utility. But salt marshes, mudflats and algal beds are more easily distinguished and mapped than the subtleties of peatlands and forested wetlands. Here is how NWI plays out in the search for Southeast’s largest estuaries: