Where the Wild Things Were: Amphibian Surveys in Kitsap Country, WA

Important to the health of the Puget Sound region, city parks can be restored to create riparian habitat that function as protective barriers for aquatic wildlife. The Environmental Protection Agency (EPA) uses amphibians as a cost-effective bioindicators for stream and wetland health. The purpose of this study was to survey amphibians in three different parks in Kitsap County, WA. Each urban park represented: 1) a highly disturbed park, 2) a 15-year-old restored park, and 3) an undisturbed park. To survey amphibians, two trap methods were used. The first method used four minnow traps per site, set weekly for four months (June-September 2018). Traps were set overnight and checked after 10 hours. The second method utilized non-chemically treated plywood boards, laid on the ground and lifted to record individuals that were present. Boards were 30 cm × 30 cm and placed in groups of four, 12 per site, and surveyed twice weekly. All sampled individuals were caught and handled under sterile conditions. Each amphibian that was sampled was placed in a bucket to be identified, weighed, and immediately released. Our results indicate that amphibian species were absent around streams in the highly disturbed park. The other two parks, the undisturbed and 15-year-old restored park, had similar species richness. The undisturbed site contained five amphibian species. Of these, two species were native salamanders, two were native frog species, and one was the invasive American bullfrog (Rana catesbeiana). Our 15-year-old restored park contained three native salamander species. Although the richness was slightly lower, the number of individuals sampled was consistently higher. Interestingly, the 15-year-old restored park harbored the rough-skinned newt (Taricha granulosa) with no signs of the invasive American Bullfrog. This newt may be potential natural biological control agent due to its highly poisonous skin and is lethal when ingested, meriting further research