Joggers on Marsh Island, cyclists on the Dawson Trail and commuters on the 545 know them well: those sunbathing turtles lined up on fallen logs below the freeway, necks stretched out, watching the world go by, seemingly satisfied and so, so smug.
After the dredging and dumping of the 520-Arboretum shoreline in the 1960s, the red-eared slider turtle has emerged as the dominant reptile in the man-made world of Lake Washington. They have done well in the aquatic environment of the freeway with its many basking areas and turtle food habitat of plants, insects, amphibians and fish. Red-eared sliders are native to the American South and likely came here as pets, then released into the wild and forced to compete with our western pond turtles – of which few, if any, now remain.
Ancient as red-ears are, these turtles have evolved into fast movers. They are called sliders for their ability to evade predators by quickly sliding off rocks and logs and into water where they can hold their breath for hours. Unlike other turtle species, they can’t breathe under water, nor can they through their cloaca, however, what they lack in underwater butt breathing they make up with on-the-ground toughness. Here’s a red-ear talking trash to a heron:
Soon we’ll find out just how tough these turtles are. Along with plans for the expansion of 520, WSDOT is planning to demolish the Arboretum ramps and regrade the adjacent shoreline area into new wetlands – again. The plan is to move 28,000 cubic yards of earth. That’s enough to completely cover the existing 1.5 mile 520 floating bridge with 6-inches of dirt — or two-way topsoil, if you prefer.
Standing up to herons is one thing. Standing up to bulldozers is another. Will the red-eared sliders survive another man-made wetland? Come back in 50 years to find out.