The Copper River Delta pulse study: an interdisciplinary survey of aquatic habitats.

Abstract

In July 1987, a 2-week synoptic survey was conducted on the wetlands of the Copper River Delta by an interdisciplinary team of scientists. Disciplines included geomorphology, limnology—water chemistry and nutrients, plankton and macroinvertebrates, anadromous fish populations, and wetland plant ecology. The purpose of this report is to present a summary of the findings of each group, preliminary conclusions, and recommendations for further research. The results are limited in scope due to the limited observation time and the single point in the year—midsummer. Because all observations were done concurrently at similar sites, the results are linked in time and place. Trends in productivity across the wetlands appear in the results. High rates of methane production indicated higher levels of production in ponds and beaver sloughs than expected as well as anaerobic decomposition processes in the ponds. Greater diversity in both phytoplankton and zooplankton species were observed in the ponds and sloughs than in glacial streams. Beaver ponds, sloughs and woodland streams were found to support the highest densities of juvenile coho salmon. Sockeye salmon were observed in the wetland and intertidal sloughs. The results indicated that complex interactions occur among geomorphology, plant succession, nutrient cycles, and hydrologic processes affecting biological production. Research should address ecosystem processes, linkages throughout the trophic structure, and successional stages within the wetlands.

Citation

Bryant, M.D., tech. ed. 1991. The Copper River Delta pulse study: an interdisciplinary survey of aquatic habitats. Gen. Tech. Rep. PNW-GTR-282. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station