In 2002, Discovery Southeast began a 2-year study of amphibian habitat, principally within half a mile of the Juneau road system, but in following years branching out to other parts of northern Southeast Alaska. We (Armstrong, Willson & Carstensen) soon noticed that toad, frog and newt stillwater breeding habitat could almost be considered the inverse of aquatic habitats selected by anadromous fish.

Beaver ponds and stillwater sloughs on large delta at head of Windfall Lake, south of L’ux, milky (Herbert River).

In consequence, while moving waters important to the Southeast ‘money-fish’ (salmon and trout) have been intensively researched for more than a century, the quiet spawning ponds of inedible (even toxic!) herps are almost completely unstudied, and even unclassified.

For our study, a geomorphic classification seemed most appropriate. In other words, what are the geological and biological agents of pond formation? Here they are, listed roughly in order from most recent (and rapidly changing) to most ancient (and successionally stable):

human  anthropogenic

beaver created and actively maintained by beaver

glacial  kettles, etc uncovered since peak of Little Ice Age

uplift Ï ponds on former tideland developed since Little Ice Age

fen  ponds on gently sloping sedge/herb dominated peatlands

bog  ponds in sphagnum-dominated peatlands

bedrock  controlled by bedrock, includes larger lakes

Beaver-impounded pond on upper Ch’eet’ Taayí, murrelet fat, (Cowee Creek), which flows across the background of this view. Test yourself with these questions: 1) Which way does the stream flow? 2) How old is the dam?

Okay, got some answers to the caption questions? Principle control on this pond is the dam in center distance, which appears to step down toward the right, direction of stream flow. Almost all drowned spruces have sluffed their bark but retain medium-sized branches—class III decay—which takes a couple decades. Snags lacking branches are also broken-topped and on slightly higher ground, possibly remnants from an earlier impoundment.

In this section

Aquatic insects book

Aquatic insects in Alaska John, Kathy and Bob collaborated on this amazing publication—yet another in Armstrong’s rich library of self-published…

2012 | John Hudson, Katherine Hocker, Robert Armstrong | 142 pages

Western toad declines

Mysterious declines As most longtime Southeast residents are aware, we’ve suffered a major decline in western toad, recently renamed Anaxyrus…

2014 | Richard Carstensen |

Habitat use of amphibians in northern Southeast Alaska

Final report on Discovery’s 2-year study of amphibian habitat relations. Population numbers, breeding pond origin types, and amphibian natural history…

2003 | Richard Carstensen, Mary Wilson, Robert Armstrong | 77 pages