Community Structure and Secondary Production of Aquatic Macroinvertebrates in Coastal Wetland Ponds of the West Copper River Delta, Alaska, Following Tectonic Uplift
Community Structure and Secondary Production of Aquatic Macroinvertebrates in Coastal Wetland Ponds of the West Copper River Delta, Alaska, Following Tectonic Uplift

Author: Ryan G. Van Duzor

Publisher:

Published: 2011

Total Pages: 128

ISBN-13:

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The Great Alaska Earthquake of 1964 (magnitude 9.2) greatly altered the coastal landscape in southcentral Alaska and had particularly dramatic effects on the Copper River Delta (CRD), an ecologically and economically important area within the Chugach National Forest. The earthquake caused tectonic uplift (up to 3.5m) of the CRD coastal tidal marsh and transformed it into a perched freshwater marsh. Copper River Delta ponds, which are crucial habitat to a myriad of migrating songbirds, shorebirds, and waterfowl, are of particular interest to wildlife managers in the CRD and along the Pacific coasts of North, Central and South America. This study was conducted to characterize the general ecology of CRD ponds, with particular focus on aquatic insect communities. Twelve ponds in two geomorphologic zones were studied to compare physicochemical characteristics, aquatic insect community structure and annual secondary production. Six ponds were in the Uplifted Marsh (UM), which was formed as a result of the tectonic uplift, and six ponds were in the Outwash Plain (OP), an area that was present before the earthquake and was relatively unaffected by tectonic activity. Uplifted Marsh and OP ponds were similar with respect to basic physicochemical parameters. Callicorixa vulnerata (Uhler 1861) (Hemiptera: Corixidae) was the numerically dominant non-dipteran taxon in 11 of the 12 study ponds and represented 30-81 % of all non-dipterans collected. Densities of the numerically dominant predators, Aeshna spp. (Odonata: Aeshnidae) and Enallagma spp. (Odonata: Coenagrionidae) were higher in OP ponds (

Aquatic Community Responses to Stream Restoration
Aquatic Community Responses to Stream Restoration

Author: Aaron Eugene Martin

Publisher:

Published: 2007

Total Pages: 108

ISBN-13:

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"Many aquatic ecosystems in the Pacific Northwest have been impacted by land use activities. Often these impacts have resulted in deleterious effects that directly or indirectly limited the capacity of habitat to produce fish. Habitat restoration potentially increases the quantity and quality of resources available to the aquatic communities within these impaired systems, thus increasing biotic integrity and fish production. In this study, responses of aquatic communities exposed to woody debris bundle and salmon analog additions were measured in the year following creation of off-channel, fish habitat in southcentral Alaska. Biofilm, invertebrates and juvenile coho salmon, Oncorhynchus kisutch, were sampled in four treatment types (control, wood, analog, and analog+wood). Biofilm significantly increased in analog enriched treatments. No treatment effects were detected in benthic invertebrate responses, however, treatment differences were detected in coho diets. Coho density and standing stock were significantly higher in the wood treatment, and coho in the control treatment showed signs of density-dependent limitations. Condition for fish was highest in the analog enriched treatments after treatment additions. These results suggest salmon analog and woody debris bundle additions may be viable short-term restoration tools, providing a boost in food and shelter for aquatic communities in habitats undergoing restoration"--Leaf iii.