Trek through 'the flats' reveals beauty of wetlands

Posted: Sunday, July 11, 2004

I was eager to get to Mendenhall Wetlands State Game Refuge early in the morning of June 4. The reason for this was that the lowest tide on the West Coast in 17 years would be occurring; a minus 4.7. This low tide would happen at 8:45 a.m. and I wanted to be there to see it. I planned to observe this tide on the south side of the mouth of the Mendenhall River. As I stood on the edge of the mudflats at the river's mouth I watched 2 harbor seals observing me in typical harbor seal fashion. The mudflats were spectacularly expansive at this lowest of low tides. As the tide turned from slack to flood, I also turned to head back to the Dike Trail going through "the flats ."

In reading a little about the history of the Mendenhall Wetlands, people have been referring to it as "the flats" for a long time. In 1879 John Muir, who came to Alaska to study glaciers, and S. Hall Young, a Presbyterian minister, traveled together through the flats. In the early 1900s a practical joke was played by a local miner who professed that he had found gold on the Mendenhall flats. As you can imagine this joke caused a stampede of miners to look for gold on the flats. Prior to 1976 when the Alaska Legislature created the Mendenhall Wetland State Game Refuge, the flats were used for many purposes. The Auk tribe used the wetlands to gather natural resources. In the teens a dairy farm was located at the present site of the Juneau airport. In the mid-1920s martin, mink, and fox farms existed on the wetlands and in the mid-1930s landing strips were created by the military. In the late-30s farmland was sold to Pan American Airways for use as an airfield which the Army enlarged several years later. Ultimately the city of Juneau obtained the airport property which over time has evolved as Juneau International Airport. In 1960 the Army Corps of Engineers dredged a navigational channel between Gastineau Channel and Fritz Cove/Stevens Passage, of which the deposits formed the "sand islands" which have existed on the wetlands ever since. Egan Drive was constructed in the 1970s and much of the wetlands were filled then.

Changes to the wetlands are not only human related. The wetlands are slowly rising by half-inch per year due to glacial rebound, a process that occurs when glacial retreat relieves the land of its tremendous weight. Future plans for a bridge from the Mendenhall Wetlands to north Douglas Island and the airport expansion would whittle away even more of the wetlands.

The ongoing loss of the Mendenhall Wetlands is not an unusual phenomenon. Scientists estimate that the Lower 48 has lost over half of its coastal wetlands since colonial times. Much of this loss has occurred because of erosion and subsidence. Human activities including dredging and filling wetlands have contributed greatly to these losses. Alaska contains nearly half of the nation's wetlands. This makes it particularly important for Alaska to conserve and preserve wetlands. Wetlands are important because they provide food and shelter for juvenile fish and feeding and resting areas for migrating birds. They also clean and filter water. As water passes through the wetlands sediments are filtered out, vegetative matter is decomposed, and nutrients are recycled. In some areas wetlands control flooding. An analogy between wetlands and the kidneys is often made because they both clean and control water flows.

Wetlands provide unique habitat for fish and wildlife. There are 17 freshwater systems that flow into the Mendenhall Wetlands. Salmon use most of these streams. The Mendenhall River, the largest of these systems, contains four species of salmon, as well as Dolly Varden char, cutthroat and steelhead trout. Eulachon runs in the lower river in the spring.

The Mendenhall Wetlands are one of three sites in Southeast Alaska recognized by the Alaska Shorebird Conservation Plan as an important resting and feeding area for migrating shorebirds. The extensive salt marsh of Mendenhall Wetlands is the primary reason for this designation as shorebirds feed on amphipods that live in the salt marsh. Bob Armstrong, local biologist, explained this process to me. The salt marsh is intertidal and as the tide floods and ebbs it brings algae, which gets caught on the vegetation. Amphipods, which feed on algae, gravitate to the marsh and are then gleaned by shorebirds. Salt marsh is important for young salmon as they also feed in this area. The two other recognized salt marsh areas in Southeast Alaska are the Stikine River Delta and the Yakutat Forelands.

• Members of the Mendenhall Wetlands Refuge Citizens Advisory Group contributed to this report.

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