So – I’m asked to review a proposal to restore a small section of a local stream such that one mile of spawning habitat will be opened up to potential salmonids. Cool. Or is it? In developed and developing stream basins, restoring the physical habitat of creeks is sometimes no favour to salmonids looking to make it their new home. Although we place logs in the restored channel to provide shelter from predators and fast currents, plant native vegetation in the riparian zone in place of non-natives, add gravel and cobbles over sand and mud, and maybe work some sinuosity into a once-straightened section, there are to consider the things we cannot see. Huh? Well, often, despite the vast (and necessary!) improvements to the physical habitat of the stream, the chemical habitat may prove to be inhospitable to spawning salmonids and/or their offspring. By creating an attractive physical habitat in which to spawn, a highly sought-after trait among the often-desperate salmonids returning to urban/urbanizing areas, we are often spending tens of thousands of dollars per project only to create an environment that draws but cannot sustain them. We simply cannot develop land in our usual boorish manner and expect a few logs and native plants to keep our salmon around. These fish need cool clean water. That means no runoff from urban and industrial developments. It doesn’t have to be so hard.
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