Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

Land Use
The rugged topography of the western Olympic Peninsula and the Oregon Coastal Range
has limited the development of dense population centers. For instance, the Nehalem
River and the Umpqua River basins consist of less than 1% urban land uses. Most basins
in this region have long been exploited for timber production, and are still dominated by
forest lands. In Washington State, roughly 90% of the coastal region is forested
(Palmisano, Ellis et al. 1993). Roughly 80% of the Oregon Coastal Range is forested as
well (Gregory 2000). Approximately 92% of the Nehalem River basin is forested, with
only 4% considered agricultural (Belitz, Hamlin et al. 2004). Similarly, in the Umpqua
River basin, about 86% is forested land, 5% agriculture, and 0.5% is considered urban
lands. Roughly half the basin is under federal management (Carter and Resh 2005).
Habitat Modification
While much of the coastal region is forested, it has still been impacted by land use
practices. Less than 3% of the Oregon coastal forest is old growth conifers (Gregory
2000). The lack of mature conifers indicates high levels of habitat modification. As
such, overall salmonid habitat quality is poor, though it varies by watershed. The amount
of remaining high quality habitat ranges from 0% in the Sixes to 74% in the Siltcoos
(ODFW 2005). Approximately 14% of freshwater winter habitat available to juvenile
coho is of high quality. Much of the winter habitat is unsuitable due to high
temperatures. For example, 77% of coho salmon habitat in the Umpqua basin exceeds
temperature standards.
Reduction in stream complexity is the most significant limiting factor in the Oregon
coastal region. An analysis of the Oregon coastal range determined the primary and
secondary lifecycle bottlenecks for the 21 populations of coastal coho salmon (Nicholas,
McIntosh et al. 2005). Nicholas et al. (2005) determined that stream complexity is either
the primary (13) or secondary (7) bottleneck for every population. Stream complexity
has been reduced through past practices such as splash damming, removing riparian
vegetation, removing LWD, diking tidelands, filling floodplains, and channelizing rivers.
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