Latest DFG survey shows Delta Fisheries continue to court extinction: historical lows for striped bass and splittail

The California Department of Fish and Game has released the results of their annual Fall Midwater Trawl of pelagic (open water) species in the Delta.  The results continue to demonstrate an estuary in collapse.  The study, which produces indices of “relative abundance,” has been conducted since 1967.  The collapse of Delta species mirrors the decline of salmonids.  Sacramento River fall-run Chinook salmon, numbering some 750,000 in 2002, dropped to 90,000 in 2007 to 66,264 in 2008 and to a dismal new low of 39,530 in 2009, before rebounding slightly this year.

Results of the 2010 Fall Midwater Trawl reveal that:

  • Striped bass populations continue to collapse.  The 2010 index of 43 showed a 40% decline from last year’s historical low of 70.  The index was 12,473, as recently as 1983.
  • Splittail populations also matched their historical low.  The 2010 index was 0, compared to last year’s index of 1.  The splittail index was 281 in 1998.
  • Delta smelt continued to be found at near record low numbers.  The index of 29 was only slightly higher than last year’s 17.  In 1993, the index was 1,078.
  • Longfin smelt rebounded slightly to 191 from last years abysmal index of 65.  Of course, in 1982 the index reached 62,905.
  • Threadfin shad numbers also increased slightly to 120 from last years record low of 13.  In contrast the index was 15,267 in 1997 and 14,401 in 2001.
  • The American shad index increased from last years 624 to 683; still the fourth lowest since records have been kept.  As recently as 2003, the index was 9,360

MidWater Trawl Graphs,    Midwater Trawl Numbers

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