Exploratory Evaluation of Nutrient Enrichment and Frog Response at Conboy Lake National Wildlife Refuge: Environmental Contaminants On-Refuge Investigation Project ID: 1N56.

摘要

We sampled nutrient and water quality parameters and surveyed Oregon spotted frogs (Rana pretiosa) life stages (eggs, larvae and recently metamorphosed juveniles) to identify the potential for agriculture-related nutrient enrichment problems at Conboy Lake National Wildlife Refuge (Conboy Lake NWR), Klickitat County, Washington. Aside from selective conditions (exacerbated summer eutrophication during a drought year (2000)), primary nutrients levels (nitrogen and phosphorus) were generally low. Values for both nutrients and other water quality parameters were generally lower than those recognized as compromising the life stages of western North American ranid frogs. Moreover, available data, suggest no significant problem with eutrophication. Nonetheless, Conboy Lake NWR comprises part of a wetland system that exhibits a naturally eutrophic cycle that peaks in late summer. With climate change scenarios predicting increasingly droughty conditions for the region and a high potential existing for human development in the Glenwood Valley, at least periodic monitoring should be implemented to avoid jeopardizing this largest remaining population of Oregon spotted frogs through inadvertent nutrient enrichment.