Friday, August 5, 2016

Lake Union: The Human Impact

Dick Wagner, the Founding Director of The Center for Wooden Boats, explores the ecology of the lake destined to unite the saltwater and freshwater sides of the Ship Canal. This essay was originally published on the CWB blog Shavings.

Engraving of Lake Union, 1891. Courtesy University of Washington Special Collections.

Western Washington has a mystique. It’s a unique blend of snow-capped mountains, misty rain forests, waters everywhere (an inland sea, bays, lakes, rivers), whales, elk, salmon, and mild, mosquito-free climate. These diverse natural elements are entwined in a complex, self-sustaining order. The threads of its beautiful tapestry began to weave together about 13,000 years ago when the 3,000-foot-deep Vashon Glacier retreated. 

Unfortunately, after thousands of years of perfect primal coordination, this mixture of natural wonders is falling apart. A textbook example of why this is happening to our once perfectly-aligned environment is Seattle’s little Lake Union, now one of the most heavily-altered water systems in western Washington.

The Pre-industrial Lake

When the lake was at its prime, many shoreline plants were of value to the birds and fish and also the human inhabitants. Native tribespeople used Oregon grape for food, made dye from its roots, and an infusion of its bark for skin and mouth sores. They employed yarrow for hair wash, perfume, colds, stomach trouble, and as a general tonic. Skunk cabbage roots were an emergency food; the raw root is as hot as a pepper. It was also used as a blood purifier and for stomach and bladder trouble. Cabbage leaves were made into a healing poultice and also rolled into berry containers or drinking cups. The blossoms, when heated, were applied to rheumatic parts for relief. Springtime skunk cabbage was gobbled by the elk. 

Native healers drew on nightshade leaves to make a drink for liver and yellow jaundice. The juice from the berries thinned blood. A poultice of nightshade leaves was used for rheumatism, skin diseases and abscesses. Natives cooked lady fern and bracken roots and served them with salmon eggs. Nettle was peeled into thin strips and twisted into strong twine for securing bone and stone tool handles and duck nets. Spirea stems also were used to make twine. Pond lily roots were heated and applied to rheumatic body parts. 

When the wapato was lost, native peoples also was lost a cash cow that needed no cultivation. Wapato is the root of arrowhead, an edible tuber. Duwamish women felt for the roots with their bare feet while walking in the shallows, pulled them, and brought them back by canoe to the longhouse, where they were roasted. This “baked potato” was considered haute cuisine. The wapato by Lake Union was so plentiful that there was a surplus to trade with other native groups. Wapato was the chief part of the Duwamish economy for many generations.

The Era of Change

The first residents of Lake Union were about 100 Native Americans whom we call the Duwamish. In the basin of Lakes Union-Washington-Sammamish there were approximately 2,000 more Native Americans. Before the coming of European and American settlers, a roughly balanced relationship was maintained between plants, animals and humans. Today, about 500,000 people live around the lake and about a million live in the greater basin. A growing human population creates buildings, highways, bulkheads, docks, dams and parking lots that all challenge this region’s ecological equilibrium. The process of filling in a South Lake Union shoreline in 1962 forced a mountain up from the lake’s bottom - a mountain of muck. Now a red navigation buoy is moored to warn of the peak of the lake’s pinnacle only 10’ below the surface of the water.

The filling of Lake Union’s shoreline and building of docks and bulkheads began in 1870 and continued until 1967. Between the Fremont Bridge and University Bridge are 700 acres of water. It used to be 900 acres. The fill displaced shallow water which was an incubator, home, hotel and restaurant for a chain of plants and animals. Small fish, including minnows, salmon and trout fry, used the shallows to feed. The plants on and adjoining the lake included wapato, skunk cabbage, nightshade, cranberries, elderberries, smartweed, lady’s thumb, nettles, spirea, miralus, forget-me-nots, yellow mustard, water celery, pond lily, camas, Oregon grape, coltsfoot, yarrow, duckweed, cattail, willow, cottonwood, alder and Indian plum. 

Birds feeding in the shallows included killdeer, flycatchers, red-winged blackbirds, white-crowned sparrows, towhees, robins, black swifts, kingfishers, ospreys, Cooper’s hawks, chickadees, tule wrens, red-backed sandpipers, greater and lesser yellow-legs, great blue herons, goldfinches, bitterns, Virginia rails, and the herring, short-billed, ring-billed, California, and glacous-winged gulls. Nesting waterfowl were pied-billed grebes, mallards, coots, and cormorants, and meadowlarks. Migrating waterfowl, including red breasted mergansers, scaups, wood ducks, pintail, buffleheads, eared grebes, western grebes, common loons, bald pates, blue-winged teals, shovellers, green-winged teals, gadwalls, dowitchers, bald eagles, black-tailed plovers, whistling swans, and Canada geese, found food in the shallows, which also were home to frogs, tadpoles, turtles, snails, crawfish, mussels, dragonflies, damsel flies, nightjars, protezoans, mice, muskrats, weasels, otters, mink, and beavers.

When creatures lose their usual places for food, nesting, hibernation or refuge, they leave. There are no more meadowlarks around Lake Union because there are no more meadows. Fortunately, even though the salmon population has dramatically declined in Lake Washington, there are still enough near-shore habitats for the Lake Union sockeye fry to linger for a year. My litmus test is that the great blue herons and kingfishers still hang out in the shallow areas for a good meal of young sockeye. On the other hand, a litmus test was not needed in 2008 to prove that the waterfowl population, both permanent and migrating, was virtually wiped out on Lake Union. The only birds now seen are a stunningly reduced number of Canada geese, mallards, coots, seagulls, kingfishers, blue herons, and cormorants. The weasel and mink are gone. There are small numbers of muskrats, otters and beavers. 

In the late 1960s our child’s first words were “quack quack.” Mallard talk on Lake Union now is virtually lost, but not forgotten. 

In the beginning Lake Union’s connection to Puget Sound was Ross Creek at the north end, which emptied into Salmon Bay, an inlet of the Sound. The 8’ to 20’ flood tide pushed up the creek to its mouth where the Fremont Bridge now stands. The brackish water of the creek and Salmon Bay was an environmental adjustment for the salmon coming home from the ocean to spawn in the lake’s freshwater streams and also for the salmon fry waiting to grow big enough to swim in the Pacific Ocean. Native legends refer to whales entering Lake Union through a hidden tunnel. In fact, any of them could have done it simply riding the tide into the lake. It’s probable that fish-eating orcas would be tempted to ambush the home-coming salmon at the mouth of Ross Creek.

When the Ballard Locks were completed in 1916, a convenient connection between the lake and the Sound was provided for boaters. There was no more transition between saltwater and freshwater. This was an inconvenient connection for salmon and even the whales. In addition, road and trolley tracks were installed on fill around the lake. Salmon spawning streams were redirected into pipes as their outlets were filled and bulk-headed; these pipes were barren of the pebbles needed for fertile eggs to be laid.

As the lakeside developed, the shallows disappeared. Bright street lights were installed. The sounds of motor vehicles, seaplanes, trolleys, sawmills and boatyards replaced the calls of birds. The forests around the lake were logged off. This cut-and-build development expelled the nesting places and sealed off the sand and gravel that was the habitat of small fish, frogs, salamanders and turtles.

Because of the Locks and because the logged lake basin allowed stormwater to drain into the lake, it was deliberately lowered two-and-a-half feet each fall and raised the same amount each spring. The change of depth had an impact on remaining marshlands. In addition, during our rainy season, the stormwater pipes overflowed and added street and sidewalk dirt and trash to the lake. The lakeside didn’t have a sewer system installed until 1967. Because of the steady flow of the Cedar River through Lake Union, the streams in pipes and the underwater springs, the lake was relatively clean. The crayfish were so prevalent in the lake that they were commercially fished through the 1970s. Crayfish will not live in toxic waters.

There was little or no direct human predation of the plants and animals of Lake Union but new species introduced to Lake Union caused unexpected impacts. The Norway rat was the scourge of the shoreside. They ate the bird eggs in the marshland nests. The rats came from Europe via trade vessels. Carp came from Asia via Europe. They root up the shallow water plants and roots that were food for waterfowl. There are now 24 non-native fish that have been introduced to the lake, including smallmouth and largemouth bass, which eat juvenile salmon. The non-native Eurasian watermilfoil dominates much of the shoreline and the non-native Himalayan blackberries have smothered many historic waterside plants.

Lake Union Today

What Lake Union was we will never see again. Even if there was a skunk cabbage farm on the lakeshore, the elk wouldn’t dare try to cross the congested traffic to get a nibble. What we can achieve is a lake sustained to the best possible state of ecologic balance. 

How can we go about this?

We can crusade against the further building of lake-edge bulkheads and roads. We can advocate for the removal of all non-native plants and against the introduction of non-native fish. Then, seed-by-seed, drop-by-drop, bird-by-bird, fish-by-fish, Lake Union can recover some of the elements that were integral parts of its Northwest mystique. 

Lake Union Dry Dock, Courtesy of Puget Sound Maritime Historical Society.