Although it may be impossible to eliminate invasive species from the refuges, measures can be taken to reduce their impact and prevent further invasions. Certain invasive species can be controlled using mechanical, chemical, and biological methods. Tansy and Canada thistle can be spot-treated with herbicides. Adult bullfrogs can be intensively harvested to reduce local populations. While these measures have proven to be effective, they are labor intensive, costly, and can have unintended short-term impacts to native species.
Surface water is a common feature to all three refuges.
The numerous springs, streams, sloughs, and ponds provide important habitat for a great variety of native wildlife, including rare and declining species. Pierce NWR supports one of only three remaining runs of chum salmon in the lower Columbia River. In addition to chum, a small run of coho and a few remnant fall chinook and steelhead also spawn in Hardy Creek, although upstream migration is precluded by concrete culverts on the creek at State Highway 14 and the Burlington Northern Railroad. Adult coho salmon, winter steelhead, Pacific lamprey, and river lamprey return to Gibbons Creek at Steigerwald Lake NWR to spawn in the upper watershed, which also supports resident cutthroat trout. The refuges also provide important habitat for pond breeding amphibians and reptiles such as Western toad and painted turtle.