Lesson 1: How to build a fish nursery
June 12, 2008 · Updated 10:44 AM
The Port Orchard shoreline may not be fish-friendly, but fish are coming anyway.
A recent analysis found a half dozen fish species including the endangered Chin-ook salmon regularly brave narrow culverts, concrete bulkheads and pollution to spawn on Port Orchards beaches and in local streams.
However, the city isnt willing to let the fish do all the work and take all the risks. Officials plan to use the analysis report to find ways to make a borderline bad shoreline habitat much more hospitable to fish.
With a few changes here and there, we could drastically improve the habitat, said city planner Rob Wenman.
According to the report, first distributed at the Oct. 14 Port Orchard City Council meeting, nearly every inch of Port Orchards waterfront has been altered in some way over the years.
The report particularly emphasized the problems caused when the expanding city filled in much of the shoreline area facing downtown and extended extensive piers that allowed even more over-water development.
Very little of the Port Orchard shoreline is natural and not hardened, the investigators said in the report.
The issue of hardened shoreline is a key one in Port Orchard. According to the report, bulkheads installed to protect buildings and roads contribute to erosion and make it nearly impossible for a fish-friendly environment to form.
The report said fish particularly bait fish like surf smelt and juvenile migrating salmon like shade, preferably from trees and other natural vegetation, and gravel-bottomed beaches with gently sloping grades. Bulkheads are vertical structures and do not erode naturally to recharge pebble deposits.
Lisa Berntsen, who co-authored the report and presented it at the council meeting, said it would take little more than a few truckloads of gravel a year to make many parts of the citys shoreline prime spawning sites again.
The report also took an in-depth look at the citys two major salmon streams Ross Creek and Blackjack Creek.
The research team didnt find many signs of fish in Ross Creek and blamed a too-small culvert that allows water from the creek to travel under Highway 166. The culvert, the scientists said, backed up silt until the mouth became too shallow for spawning.
Even upstream, the team found few places fish such as trout and salmon could spawn.
The constant influx of gravel to the creek appears to continually fill in the (spawning) pools as they form, analysts said in the report.
Blackjack Creek, fares much better, fish-wise. According to the report, the teams were surprised to see hordes of fish using the stream to spawn a report done back in 1987 had found the creek had too much silt to allow eggs to survive. As it turns out, the biologists wrote, the fish have been doing their own housekeeping since then.
Large numbers of spawning fish appear to be keeping the substrate (gravel) clean, they said in the report.
It is unknown yet how much the city intends to do to improve Port Orchards shorelines. Many of the reports recommendations replacing bulkheads, rebuilding beaches, cleaning up pollution and garbage are costly propositions. However, Wenman said the report is mostly intended to serve as a starting point not necessarily a to-do list.
It sets a baseline of where we are with shorelines today, he said.