What is happening?
Physical and Chemical Qualities of Water
Puget
Sound 2003
Click on the map at right to view a larger version.
Source: CommEn Space
In Puget Sound, half of the 24 core stations had fair water quality
and half had good water quality. The stations reporting fair water
quality results were typically located near urbanized areas such
as Port Angeles, Mount Vernon, and Tukwila, or adjacent to farming
areas such as Darrington and Puyallup. For the 22 basin stations
(e.g, Nooksack, White River, Dungeness, Snoqualmie, Union rivers)
14 had fair water quality, seven rated good, and one had poor
water quality.
The Nooksack River, briefly discussed below, received the poor
rating.
Georgia Basin 2003
In the Georgia Basin, water quality index results from 16 sites
indicate that five were excellent, five were good, three were
fair, two marginal and one poor.
The Fraser River was monitored at five locations and, of those,
two were excellent, two good and one fair. The Fraser River is
the largest salmon producing river in the world and, of the 300
important salmon spawning streams in the Fraser River system,
approximately half are found in urbanized areas of the Lower Fraser
Valley.
65 percent of the Coho and almost all of the chum salmon in the
Fraser come from this system. The Fraser River is also flanked
by industrial outfalls from paper and pulp production, cement
plants, sewer treatment plants and forestry activities.
Biological Qualities of Water
Puget
Sound 2003
Click on the map at right to view a larger version.
Source: CommEn Space
In Puget Sound, 32 of the 50 test sites, roughly 64 percent,
were considered impaired. These sites were located in areas that
included forest harvest activity, agricultural activity, and in
urban environments. Most of the sites determined to be biologically
impaired were found in forested settings throughout the Puget
Lowland, Cascades, and North Cascades ecoregions. The dominant
source for impairment appears to be land use conversion from forested
to home and warehouse development.
The Role of Forests and Development: Removal of forested
areas contributes to "breaking up" the forest into disconnected
or isolated areas called "patches." This patchiness
means that polluted runoff is not captured by forests as efficiently
during the rainy season and, ultimately, the forest provides a
lower level of protection to streams from sediment and pollutants
associated with polluted runoff.
Increased development of residential homes, as well as warehouses
and businesses, represents a transition toward an urbanized environment.
The number of impaired sites in urbanized settings equaled those
surveyed in agricultural settings. Streams in both agricultural
and urban settings often had the same physical characteristics.
These habitat characteristics included streams with deeper, wider
channels with fine sediment, and streamside plants removed, changed
or damaged in some way. Highly impaired streams in agricultural
settings had obvious signs of low diversity in physical habitat
and might only serve as conduits for migrating salmon from the
marine environment to higher quality freshwater habitat in upper
portions of watersheds.
The largest continuing threat to streams and surrounding landscape
in the Puget Lowlands and the foothills of the Cascades (and Northern
Cascades) is an increase in forest fragmentation. This elimination
of natural barriers exposes stream channels to an accelerated
rate of pollutant delivery. Management of this remaining important
stream habitat and surrounding area will determine the success
in maintaining and restoring important biological resources for
this region.6
Georgia Basin 2003
The most significant threat to water quality in the Georgia Basin
is the continued population pressure by urban growth and development
and intensive agricultural practices. Urban streams are affected
by unnatural flow fluctuations due to impervious surfaces and
increased surface runoff during the rainy season.
Sediment and chemical pollution accumulated on paved surfaces
ultimately ends up in the stream through run-off or through storm
drains. Agricultural streams are affected by habitat destruction
by livestock, reduced or absent streamside vegetation along the
stream banks causing increased erosion and sediment input, contamination
of chemicals by leaching and surface runoff and increased nutrient
input from fertilization and manure application. Too many nutrients
in water can reduce oxygen in the water which makes organisms
sick or kills them.
In Georgia Basin, 46 streams exposed to urban and agricultural
activities were assessed using the Fraser River/Georgia Basin
reference condition model and biological quality classifications
were assigned using the BEAST (Benthic Assessment of SedimenT)
method. Benthic invertebrates are animals without a backbone that
live at or near stream and lake bottoms. Ninety percent of the
test sites indicated environmental stress or compromised biological
quality. The BEAST assessments indicated that the benthic invertebrate
communities were different that what was expected at most of the
test sites. In some cases, invertebrate diversity was low while
in other cases, the diversity was high but the community was dominated
by pollution tolerant organisms such as midges and worms. Similar
to Puget Sound, the proportions of impaired sites in urban and
agricultural areas were similar.
Collaborative monitoring by federal, provincial, and municipal
governments and watershed groups will indicate where restoration
and management efforts should be focused. Benthic invertebrates
are an indicator of stream health; detailed investigations of
impaired streams are required to diagnosis the cause of the impairment
and required management actions.7
River,
Stream and Lake Quality
