Have we passed the darkest hour?
History:
From the last ice age until about 150 years ago Union Bay was in a natural and sustainable state. The water level was higher which made the bay wider and the shoreline longer. The marsh area was also larger, so the population of local and migrating waterfowl waas most likely greater as well. The northern shore was somewhere between 45th and 50th streets. Spawning salmon would have returned to Union Bay via the Duwamish and the Cedar rivers, then crossed the southern portion of Lake Washington to spawn in Arboretum and Ravenna Creeks. Deer, elk and bear almost certainly roamed the woods around the bay. The bears, eagles and the Duwamish People were fed by the returning salmon. Most likely all five of the native species of salmon (Chinook, Coho, Chum, Pink, Sockeye) returned to the bay at different times of the year. The Duwamish People had longhouses sprinkled all around the bay. Their houses would have been built from the wood of mature Western Red Cedar trees, that most likely grew very close to where they were used. The air was crisp and clean and the water pure.
This can be contrasted with the state of Union Bay in the middle of the 20th century. The creation of the Montlake Cut (1916) was an economic boon that allowed access to timber and timber mills on Lake Washington, however it also lowered the water level by nearly 9 feet. This exposed vast areas of mud around the new, smaller Union Bay. This area was then used to store trash from the city of Seattle. Attempts to control potential flooding resulted in Ravenna Creek being routed in the sewer system and Arboretum Creek being forced into a culvert before reaching Union Bay. Reduction of water flow, pesticides, sewage and pollution from motorized vehicles (on land and water) stopped salmon from spawning in the original Union Bay watershed. DDT weakened the eggs of birds and resulted in reduced populations. Various introduced species, like bullfrogs and carp, also made it more difficult for native creatures to survive. Finally when the 520 bridge was built the untreated runoff was drained directly into Union Bay.
On the other hand during this "darkest hour" there were major efforts that mitigated some of the damage. The creation of the Washington Park Arboretum, the Union Bay Natural Area and the outlawing of DDT. Lead pollution in Union Bay was reduced first when hunting was stopped and later when lead was removed from gasoline. During the last few years Ravenna Creek has been partially restored and reconnected to Union Bay.
Currently:
According to eBird during the last five years the average number of bird species sighted in the Union Bay Natural Area (UBNA) has been about 149 species per year. The highest count was 159 species in 2012. We cannot be sure why the increase occurred. People could be paying more attention or logging their results more often or there might actually be more species at the UBNA. However the good news is the species count does not appear to be decreasing.
There are three pairs of eagles nesting in the Union Bay area. There is a colony of Great Blue Herons that nest on the UW campus. Last year there were Pileated Woodpeckers and Barred Owls raising young in Interlaken Park and more in the Arboretum.
There are now four beaver lodges in Union Bay.
On the salmon front things are a bit more challenging. Up until the last economic downturn introduced salmon did return to an artificial pond on the UW campus. Their eggs were harvested manually and "raised" indoors in trays of clean water. This was required because the water flowing out of Union Bay was and is too polluted for the eggs to survive.
The Future:
Imagine all five species of salmon once again returning to Ravenna and Arboretum creeks. Imagine first grade school children watching salmon eggs hatch in their school aquariums and then taking a field trip to see their fry released into their local streams.
Imagine in fifth or sixth grade the same students take a second field trip to the same streams to see their salmon returning to spawn. From a bridge they watch the eggs being released. They also see bald eagles swooping down to pick up the spent salmon. With binoculars they watch as the eagles return the salmon to their nests to feed their young.
Imagine that in middle school and high school the students return to the same streams to help protect and maintain the native plants that provide shade and food for the salmon and their young. Imagine these students being taught the environmental intricacies of the web of life that depends on the salmon and the wetlands of Union Bay. Imagine less pollution, less cancer and healthier lives for all the children living on and around Union Bay.
A few years ago this would have seemed like an impossible dream. Today parts of this dream are starting to sound feasible. As part of the new 520 bridge construction the Arboretum Creek will be day-lighted. Wetlands damaged by the new construction will be replaced by new wetlands near by. The polluted 520 runoff will be routed into a settling pond and cleaned before it returns to Union Bay. We could potentially create even more wetlands by carefully sinking the old bridge in selected locations.
While this will be a huge step in the right direction there are other issues. There are things we can do as individuals and things we can do as a community. We need to reduce the pollution that runs off our houses, yards and streets, click here or click here to learn more. We need to plant more native plants in our yards and use less pesticides, to find out more click here. We need to increase the volume of clean cool water in our streams, click here. We need to monitor and reduce Combine Sewer Overflow near the mouth of Arboretum Creek and near the Yesler wetlands (east of the Union Bay Natural Area), click here. None of these issues are insurmountable. We simply need to be aware of our options and the impact of our choices. The future of our children and all the young on Union Bay is up to us.
Larry
Points in Time:
1854 - On July 4th Thomas Mercer states that someday Lake Ha-ah-chu (which he renamed Lake Union) will link Puget Sound to Lake Washington. This appears to be the birth of the idea of the Ship Canal and Montlake Cut.
1886 - Railway built along what is now the Burke-Gilman Trail.
1901 - Water from the Cedar River watershed is first used in Seattle.
1907 - Green Lake is lowered and disconnected from Ravenna Creek
1916 - Montlake Cut lowers Union Bay & reroutes the drainage of Lake Washington.
(There is a great 3 dimensional display at the new Museum of History and Industry that shows how Union Bay shrunk with this change.)
1926 - 1966 - Marsh areas around the bay were filled with Seattle trash.
1934 - The Washington Park Arboretum created.
194X - Hunting outlawed on Union Bay.
1948 - The rest of Ravenna Creek is diverted into the sewer system.
1963 - The original 520 Bridge was constructed.
1972 - Union Bay Natural Area created.
1972 - DDT outlawed.
1973 - Leaded gasoline phase out begins.
2006 - Part of Ravenna Creek is restored and it is reconnected to Union Bay.
2014 - 2016 Arboretum Creek is scheduled to be daylighted.
What is next is up to us.
This is cool!
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