The Restoration of Two Salmon Spawning Sites in Maple Creek, Port Coquitlam

Abstract

Maple Creek flows through Coquitlam and Port Coquitlam in British Columbia. It is a salmon-bearing stream in an urbanized watershed.  Maple Creek drains 128.2 hectares.

This report focuses on gathering data through physical, chemical and biological testing and analyzing the results.  Data was drawn from a census done on aquatic macro-invertebrates, fish trapping and water quality testing to support the installation of salmon spawning gravel at two sites.  This project is part of a multi decade restoration program outlined in the Allen Thomson Report 1997 for Maple Creek and the volunteer stewards.  The goals and objectives of the spawning gravel installation are to increase the quality and quantity of the gravel at the two sites where the returns have declined from historic norms.

Active spawning gravel installation creates habitat immediately and this will assist in increasing salmon populations.  The new spawning gravel will enhance biological function of the stream at these sites for salmon, invertebrates and other biological organisms.

Data from the weekly samplings was compared to BC Water Quality guidelines for aquatic life parameters.  Acceptable pH levels for salmon in freshwater streams is in the range from 7-9. Sustained levels below of 6 pH leads to mortality.  The pH levels met the acceptable parameters with the exception of one reading which was extremely low at 5.4.  As it was a manual reading and not a metered one it was considered by senior testers to be an anomaly. The downstream reading on that day also did not support the reading. Dissolved Oxygen results from weekly testing were within acceptable parameters given in the guidelines for aquatic health. Water temperature did not exceed the acceptable parameters.  Turbidity levels were within acceptable parameter as the stream visibility was consistent with minute amounts of sediment.

Aquatic macro invertebrate survey produced a variety of capture rates.  The most pollution intolerant macro invertebrates are the Mayfly nymph Ephemeroptera, the Stonefly nymph Pleeoptera and the Caddisfly Trichoptera or (EPT)taxa which were not predominant taxon in any of the sites sampled.  A marginal and acceptable site assessment were the final ratings.