K. Dodd: dynamics of Port Madison fish

Data from N end of Bainbridge and repeat trawl survey from Tom Quinn’s UW class (~20 trawls/year from 1991-2008, over 2nd weeend in May, 4 depths (10-70m)).  Time series started just after 1989 fish closure, so expected increase in catch rate over time, but that wasn’t the case.

Catch anomaly shows an actual catch that is higher than expected (based on number of trawls completed compared with historical average for that depth and location).  Catch anomaly decreases for rockfish and slendersole, but increased for english sole.  Some species show up episodially: 1990 pulses of shiner perch, mid90s pulse for Pacific hake, big tomcod pulse in 2000, and 2003-4 for walleye pollock.  No trend in ratfish.  English sole was most abundant overall.

It’s unclear why these declines have occurred.  WDFW has sometimes seen increases for the same species and years in other parts of Puget Sound.

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