Puget Sound’s beloved orcas are at risk of extinction and scientists say one key step to rescuing them is boosting oceangoing runs of chinook salmon, the biggest, fattest and most nutritious kind of salmon and the killer whales’ main food source. But legislators seeking to open up more than 1,000 miles of prime inland spawning areas that are currently blocked to the fish by culverts are struggling to find a funding source. What is blocking all those fish? Culverts. These are the pipes and tunnels that pass under roads throughout the state, allowing water to flow downstream. It turns out that many old highway projects in the state were poorly engineered where they intersect with salmon-bearing streams and as a result can block the fish in a variety of ways.