Temperature Monitoring

The Temperature Monitoring program has been operating in the Mattole since 1995.  Small monitoring devices called temperature “loggers” (pictured below) are placed in nearly every fish-bearing tributary of the Mattole River for the dry season, and also in the mainstem.  The loggers record the water temperature every hour for nearly six months.  In 2009 temperature loggers were placed for the first time at the USGS flow monitoring stations in Petrolia and Ettersburg.

A snorkel survey is conducted at each of the logger placement sites in the spring and again in the fall to compare the fish populations at the beginning and end of the monitoring season.  This information is compiled in a database and used to deduce long-term and short-term changes in the Mattole, and to guide habitat restoration planning.

Did You Know?

The maximum water temperature salmon can survive is 68F.  In many places in the Mattole River water temperatures can reach over 75F in late summer!

Temperature Monitoring Reports

2000 Report
2001 Report
2002 Report
2003 Report
2004 Report
2005 Report
2006 Report
2007 Report
2008 Report