Saturday, April 14, 2012

Algae Problems

Qingdao, China- Eyepress
Until the rains of a few weeks ago, Bull Creek had lots of stringy algae, both in the shallows and floating in the deep pool.  I couldn't cast a lure without collecting it in the hooks.  We were concerned about this being pollution until we saw it in first and second order streams coming in from land without humans or cattle on it.

The picture above makes me realize we didn't know what an algae problem was.  This was taken from the site of the 2009 Olympic sailing regattas just before the races were to begin in the Yellow Sea.  They had 20,000 people and 1,000 boats mobilized to clean up this area of the ocean which encompassed one-third of the race course.

Algae blooms are caused by excessive nitrogen  and phosphorus combined with low flow or stagnant water warmed by the sun.  Although the nutrients often come from agricultural or urban lawn runoff, in our case we were seeing it also in the draws draining the national forest with neither factor in their watershed.

Our fisheries consultant from MDC felt the problem was stagnant low water conditions with dead plant material building up in the unseasonably warm weather.  Lacking a cast of thousands of Master Naturalists, we waited until a nice four inches of rain over two days flushed out the stream.  We are now back to normal.

And the Olympic regatta?  Two weeks later reported that it was cleaned up with efforts that included creating two 13 mile long barriers.  I am saving these instructions for the Conservation Department if we have another bloom.

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