|
<br />8
<br />
<br />change in plant composition, relative plant abundance, and the end
<br />of high soil moisture content. Yakima River riparian corridors
<br />transport water, soil, plant seeds, and nutrients to downstream
<br />areas - and thereby serve as important migration routes for many
<br />wildlife species. These riparian areas, though small in overall size,
<br />are one of the most important sources of wildlife bio-diversity in
<br />the Yakima River landscape.
<br />
<br />Freshwater wetland habitats are water bodies less than 20 acres in
<br />size or less than 6 feet in depth and include marshes, swamps,
<br />bogs, seeps, wet meadows, shallow ponds, and lakes along the
<br />Yakima River corridor. Like riparian areas, these wetlands support
<br />species in great diversities, densities, and productivity. The wooded
<br />areas that are located adjacent to these wetlands provide nesting
<br />areas, forage, and other cover that is critical to wetland-dependent
<br />species, such as most waterfowl or small mammals like beaver.
<br />
<br />Wetlands - there are 2 principal wetland types along the Yakima
<br />River:
<br />
<br />¥ Scrub/shrub wetlands - with seasonal flooding, characterized
<br />by hardhack, willow, red alder or redosier dogwood,
<br />¥ Shallow marsh - deep marsh, and open water wetlands.
<br />
<br />Generally, these riparian zones and wetlands provide substantially
<br />more important wildlife habitat than forested areas. These riparian
<br />zones are also passageways for wildlife migrating between or
<br />around developed areas adjacent to Easton, Cle Elum, and
<br />Ellensburg. These riparian vegetation also maintain optimum fish
<br />spawning conditions by providing shade, bank stabilization, a
<br />breeding ground for insects, and a source of organic material for
<br />the stream.
<br />
<br />Wildlife species - urban and agricultural developments within the
<br />Kittitas Valley have substantially reduced wildlife habitat through
<br />the years. However, valuable habitat qualities still remain in the
<br />undeveloped, large native vegetation tracts and around the
<br />remaining wetlands and riparian (streamside) forests of the Yakima
<br />River.
<br />
<br />Yakima River wetlands and riparian zones support muskrat, mink,
<br />otter, beaver, raccoon, and weasel. Water bodies, wetlands, and
<br />adjacent agricultural fields also provide suitable nesting and
<br />feeding habitat for mallard ducks, American widgeons, green-wing
<br />teal, common coot, common merganser, blue-wing teals, great blue
<br />heron, and lessor and greater Canadian goose.
<br />
<br />The plateaus and cliffs that overlook the Yakima River provide
<br />habitat for the bald eagle and osprey. The northern bald eagle and
<br />the northern spotted owl are listed as a potentially threatened or
<br />endangered species on Washington State's endangered and
<br />threatened lists. No other endangered or threatened species are
<br />known to occur in the Kittitas Valley.
<br />
<br />Fisheries – Yakima River streams provide freshwater habitat for
<br />species of anadromous fish, including coho, chinook, chum salmon,
<br />and steelhead species that live in saltwater but return to spawn in
<br />freshwater. These fish species have evolved over time to fit the
<br />specific characteristics of Yakima River streams of origin - and are
<br />uniquely imprinted compared with other members of the same
<br />species.
<br />
<br />Anadromous fish require cool, uncontaminated water with healthy
<br />streambeds and insect populations. Vegetated riparian areas
<br />maintain stream habitats by stabilizing water temperature,
<br />producing an insect supply, controlling erosion, and providing
<br />woody debris.
<br />
<br />Naturally occurring or established species include smallmouth bass,
<br />yellow bullhead, common carp, channel catfish, crawfish, northern
<br />pikeminnow, suckerfish, walleye, and mountain whitefish. These
<br />species spawn and rear in medium sized gravel beds that are
<br />provided medium velocity water flow along the Yakima River creek
<br />channels, swamps, marshes, perennial and seasonal streams.
<br />
<br />The Yakima River historically supported large runs of anadromous
<br />salmonids with estimated runs of 300,000 to 960,000 fish a year in
<br />the 1880s. These numbers have declined drastically, and 3 salmon
<br />species were extirpated (eliminated) – sockeye, summer Chinook,
<br />and coho.
|