1 00:00:01,166 --> 00:00:03,233 And now to our "NewsHour" Shares. 2 00:00:03,233 --> 00:00:08,000 Seawalls help to protect developed shorelines, but they can also destroy crucial habitat. 3 00:00:08,000 --> 00:00:11,200 One project in Washington state aims to fix that. 4 00:00:11,200 --> 00:00:14,766 Ken Christensen of KCTS' EarthFix explains. 5 00:00:14,766 --> 00:00:19,766 KEN CHRISTENSEN: The Seattle waterfront is changing right beneath your feet. 6 00:00:21,700 --> 00:00:24,100 JEFF CORDELL, University of Washington: When you walk along Seattle's sidewalk, you will 7 00:00:24,100 --> 00:00:26,100 be walking on glass panels. 8 00:00:26,100 --> 00:00:30,766 KEN CHRISTENSEN: But look deeper, and you will see that the changes aren't for tourists. 9 00:00:31,500 --> 00:00:33,633 They're for natives. 10 00:00:33,633 --> 00:00:37,733 JEFF CORDELL: Their function is to provide light to help thousands and thousands of little 11 00:00:37,733 --> 00:00:39,833 baby salmon. 12 00:00:39,833 --> 00:00:43,733 KEN CHRISTENSEN: It's one feature of Seattle's new seawall, a $400 million infrastructure 13 00:00:45,800 --> 00:00:48,800 project that's doubling as a really big science experiment, the biggest of Jeff Cordell's 14 00:00:50,100 --> 00:00:51,600 career. 15 00:00:51,600 --> 00:00:53,433 JEFF CORDELL: Nothing has ever been tried on this scale. 16 00:00:53,433 --> 00:00:57,533 You're walking on foot after foot after foot of new habitat. 17 00:00:57,533 --> 00:01:02,533 KEN CHRISTENSEN: Cordell wants to see if coastal cities can better coexist with fish. 18 00:01:04,533 --> 00:01:07,700 For 80 years, Seattle's seawall was like most, a flat, concrete slab that held back the sea, 19 00:01:09,533 --> 00:01:13,200 but destroyed shallow water habitat that many species thrive on. 20 00:01:13,200 --> 00:01:18,200 Every spring, young salmon would migrate from Seattle's Duwamish River to the ocean, and 21 00:01:20,200 --> 00:01:23,766 they're hard-wired to stay close to shore, which means they run right into this. 22 00:01:25,700 --> 00:01:29,666 In the inky darkness under the pier, life can get confusing for a fish. 23 00:01:29,666 --> 00:01:33,466 JEFF CORDELL: There's a good example of a shadow line from a pier. 24 00:01:33,466 --> 00:01:37,033 And they don't want to cross the shadow line, so they just mill about here. 25 00:01:37,033 --> 00:01:41,800 KEN CHRISTENSEN: The new seawall is supposed to make life easier, not only by providing 26 00:01:41,800 --> 00:01:46,400 a naturally lit corridor for fish to pass through on their way to the ocean, but also 27 00:01:46,400 --> 00:01:51,233 by featuring overhangs and rocky surfaces along the way for fish food to grow on. 28 00:01:51,233 --> 00:01:53,400 JEFF CORDELL: Look at the brown scum here. 29 00:01:53,400 --> 00:01:57,566 We love to see that, because that's where the little crustaceans grow that the juvenile 30 00:01:57,566 --> 00:01:59,000 salmon feed on. 31 00:01:59,000 --> 00:02:01,433 You can't count out brown scum. 32 00:02:01,433 --> 00:02:06,433 KEN CHRISTENSEN: Most seawalls are still get built like Seattle's was back in the 1930s. 33 00:02:07,600 --> 00:02:09,633 And construction is expected to increase. 34 00:02:09,633 --> 00:02:14,166 JEFF CORDELL: There's going to be much more need for coastal infrastructure and a lot 35 00:02:14,166 --> 00:02:19,166 more thinking about how we can best create habitat for the organisms that we're removing 36 00:02:19,633 --> 00:02:21,766 it from. 37 00:02:21,766 --> 00:02:25,000 KEN CHRISTENSEN: Once the seawall is complete, Cordell plans to begin a decade-long monitoring 38 00:02:25,000 --> 00:02:28,033 project to figure out if it does what it's supposed to. 39 00:02:28,033 --> 00:02:31,933 JEFF CORDELL: Even that brown stuff needs a good amount of sunlight to grow. 40 00:02:31,933 --> 00:02:36,433 KEN CHRISTENSEN: If the experiment succeeds, the Seattle waterfront's biggest change could 41 00:02:36,433 --> 00:02:40,433 be the change it inspires in seawalls around the world. 42 00:02:40,433 --> 00:02:43,866 For the "PBS NewsHour," I'm Ken Christensen in Seattle, Washington.