WEBVTT 00:01.166 --> 00:03.233 align:left position:20%,start line:83% size:70% And now to our "NewsHour" Shares. 00:03.233 --> 00:08.000 align:left position:20%,start line:71% size:70% Seawalls help to protect developed shorelines, but they can also destroy crucial habitat. 00:08.000 --> 00:11.200 align:left position:10%,start line:83% size:80% One project in Washington state aims to fix that. 00:11.200 --> 00:14.766 align:left position:20%,start line:83% size:70% Ken Christensen of KCTS' EarthFix explains. 00:14.766 --> 00:19.766 align:left position:10%,start line:77% size:80% KEN CHRISTENSEN: The Seattle waterfront is changing right beneath your feet. 00:21.700 --> 00:24.100 align:left position:10%,start line:77% size:80% JEFF CORDELL, University of Washington: When you walk along Seattle's sidewalk, you will 00:24.100 --> 00:26.100 align:left position:10%,start line:89% size:80% be walking on glass panels. 00:26.100 --> 00:30.766 align:left position:10%,start line:77% size:80% KEN CHRISTENSEN: But look deeper, and you will see that the changes aren't for tourists. 00:31.500 --> 00:33.633 align:left position:20%,start line:89% size:70% They're for natives. 00:33.633 --> 00:37.733 align:left position:20%,start line:71% size:70% JEFF CORDELL: Their function is to provide light to help thousands and thousands of little 00:37.733 --> 00:39.833 align:left position:30%,start line:89% size:60% baby salmon. 00:39.833 --> 00:43.733 align:left position:20%,start line:71% size:70% KEN CHRISTENSEN: It's one feature of Seattle's new seawall, a $400 million infrastructure 00:45.800 --> 00:48.800 align:left position:10%,start line:77% size:80% project that's doubling as a really big science experiment, the biggest of Jeff Cordell's 00:50.100 --> 00:51.600 align:left position:40%,start line:89% size:50% career. 00:51.600 --> 00:53.433 align:left position:10%,start line:83% size:80% JEFF CORDELL: Nothing has ever been tried on this scale. 00:53.433 --> 00:57.533 align:left position:10%,start line:83% size:80% You're walking on foot after foot after foot of new habitat. 00:57.533 --> 01:02.533 align:left position:10%,start line:77% size:80% KEN CHRISTENSEN: Cordell wants to see if coastal cities can better coexist with fish. 01:04.533 --> 01:07.700 align:left position:10%,start line:77% size:80% For 80 years, Seattle's seawall was like most, a flat, concrete slab that held back the sea, 01:09.533 --> 01:13.200 align:left position:20%,start line:77% size:70% but destroyed shallow water habitat that many species thrive on. 01:13.200 --> 01:18.200 align:left position:10%,start line:77% size:80% Every spring, young salmon would migrate from Seattle's Duwamish River to the ocean, and 01:20.200 --> 01:23.766 align:left position:10%,start line:77% size:80% they're hard-wired to stay close to shore, which means they run right into this. 01:25.700 --> 01:29.666 align:left position:10%,start line:77% size:80% In the inky darkness under the pier, life can get confusing for a fish. 01:29.666 --> 01:33.466 align:left position:20%,start line:77% size:70% JEFF CORDELL: There's a good example of a shadow line from a pier. 01:33.466 --> 01:37.033 align:left position:10%,start line:77% size:80% And they don't want to cross the shadow line, so they just mill about here. 01:37.033 --> 01:41.800 align:left position:10%,start line:77% size:80% KEN CHRISTENSEN: The new seawall is supposed to make life easier, not only by providing 01:41.800 --> 01:46.400 align:left position:10%,start line:77% size:80% a naturally lit corridor for fish to pass through on their way to the ocean, but also 01:46.400 --> 01:51.233 align:left position:10%,start line:77% size:80% by featuring overhangs and rocky surfaces along the way for fish food to grow on. 01:51.233 --> 01:53.400 align:left position:20%,start line:83% size:70% JEFF CORDELL: Look at the brown scum here. 01:53.400 --> 01:57.566 align:left position:20%,start line:71% size:70% We love to see that, because that's where the little crustaceans grow that the juvenile 01:57.566 --> 01:59.000 align:left position:30%,start line:89% size:60% salmon feed on. 01:59.000 --> 02:01.433 align:left position:10%,start line:89% size:80% You can't count out brown scum. 02:01.433 --> 02:06.433 align:left position:10%,start line:77% size:80% KEN CHRISTENSEN: Most seawalls are still get built like Seattle's was back in the 1930s. 02:07.600 --> 02:09.633 align:left position:20%,start line:83% size:70% And construction is expected to increase. 02:09.633 --> 02:14.166 align:left position:10%,start line:77% size:80% JEFF CORDELL: There's going to be much more need for coastal infrastructure and a lot 02:14.166 --> 02:19.166 align:left position:10%,start line:77% size:80% more thinking about how we can best create habitat for the organisms that we're removing 02:19.633 --> 02:21.766 align:left position:40%,start line:89% size:50% it from. 02:21.766 --> 02:25.000 align:left position:20%,start line:71% size:70% KEN CHRISTENSEN: Once the seawall is complete, Cordell plans to begin a decade-long monitoring 02:25.000 --> 02:28.033 align:left position:10%,start line:83% size:80% project to figure out if it does what it's supposed to. 02:28.033 --> 02:31.933 align:left position:10%,start line:77% size:80% JEFF CORDELL: Even that brown stuff needs a good amount of sunlight to grow. 02:31.933 --> 02:36.433 align:left position:20%,start line:71% size:70% KEN CHRISTENSEN: If the experiment succeeds, the Seattle waterfront's biggest change could 02:36.433 --> 02:40.433 align:left position:10%,start line:83% size:80% be the change it inspires in seawalls around the world. 02:40.433 --> 02:43.866 align:left position:20%,start line:77% size:70% For the "PBS NewsHour," I'm Ken Christensen in Seattle, Washington.