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.

Typical array of elevational zones in northern Southeast, where land is rising relative to sea level.

Typical array of elevational zones in northern Southeast, where land is rising relative to sea level.

 

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:

The National Wetlands Inventory maps about 350,000 acres of tidal estuaries on the Tongass, about 2% of its land area. Only 42,000 acres of this are covered with “emergent” vegetation, or salt marsh. But whether marshy or muddy, each estuary is the ecological nexus of its watershed, important far out of proportion to the area covered.

The National Wetlands Inventory maps about 350,000 acres of tidal estuaries on the Tongass, about 2% of its land area. Only 42,000 acres of this are covered with “emergent” vegetation, or salt marsh. But whether marshy or muddy, each estuary is the ecological nexus of its watershed, important far out of proportion to the area covered.

Showing all 5 results

More Information

Fall 2004 Newsletter, Nexus: Estuaries of Southeast Alaska

This Discovery Southeast newsletter features an in-depth article on estuaries.  It includes notes on how estuaries develop, their food webs, and their importance to the greater ecosystem.  The newsletter also includes field journal nature sketches, a tracking exercise, and notes on Discovery Southeast.

Download here (780 kb): PDF_Download

Glacial Rebound in the Mendenhall Wetlands

This report contains GIS (Geographic Information Systems) mapping and analysis for the Mendenhall Wetland State Game Refuge.  You’ll find information on glacial rebound, vegetation types, tidal elevations, and glacial rebound, all supported by GIS maps and detailed photographs.  Conservation value for the land is also discussed.

Download Here (1.9MB): PDF_Download

Hotspots: Bird Survey of Mendenhall Wetlands (April 2002 to May 2003)

This report is the culmination of eighteen bird surveys conducted in the Mendenhall Wetlands, an area widely recognized as an important habitat for migrating birds.  The survey results are complimented by GIS maps, graphs, and extensive habitat descriptions.  Looking towards the future, this report also addresses concerns about habitat use and destruction in the Wetlands.

Download Here (6.1MB): PDF_Download

 

The Mendenhall Wetlands: a globally recognized Important Bird Area

The Mendenhall Wetlands have long been recognized as an important habitat for a large variety of birds.  This book provides an exhaustive picture of this federally recognized “Important Bird Area.”  It begins with a brief history of how the wetlands came to fall under environmental protection, and goes on to describe the birds that call the area home. You’ll also find information on vegetation, mammals, invertebrates, and ecological interactions in the wetlands.  The pages are complimented by wonderful color photographs of birds.

Download Here (6MB): PDF_Download

 

 

 

 

Wildlife “Out the Road”

This is a report from Richard Carstensen  to the Southeast Alaska Land Trust on habitats and wildlife use of glacially-rebounding valleys from 25 to 28-mile Glacier Highway in Juneau. They call this area “risen valleys,” and in the report you can trace animal use and habitat descriptions for this remarkable portion of Southeast Alaska. This report contains extensive habitat descriptions, photographs, and animal descriptions.

Download Here (4.2MB): PDF_Download