in South San Francisco Bay stations nearest the Project site has been about one fish per hectare (Table 4.C-2); data courtesy of CDFW's San Francisco Bay Study and the Interagency Ecological Program for the San Francisco Estuary). The catch rate is somewhat less than abundance per se, because of inefficiencies in the sampling gear. However, longfin smelt are an open water species and would be expected to be even less abundant near shore, where the CDFW trawling vessel could not venture. This expectation is borne out by the CDFW beach seine program, which ran from 1980 to 1986 and consisted of monthly sampling at eight South Bay Stations (Orsi 1999). This effort yielded only 7 specimens of longfin smelt, at a time when longfin smelt were approximately six times as abundant in South Bay as they are now (Table 4.C-3).
TABLE 4.C-2
AVERAGE MONTHLY CATCH (FISH PER HECTARE) OF LONGFIN SMELT
(ALL LIFE STAGES COMBINED) AT CDFW SOUTH BAY OTTER
TRAWL STATIONS*, 2001-2011
101 102 103 104 105 106 107 108 140* 49.2
4.6
2.1
8.5
2.4
5.1
8.4
56.9
4.8
19.5 0 1.1 1.1 2.4 0 105.4 18.6 0 15.1 0 0 0 4.1 7.5 12.0 14.7 4.2 7.5 0 0 4.0 2.5 0 1.1 7.0 2.9 0 0 0 0 0 0 0 11.8 0 0 0 5.9 0 0 0 0 0 0 0 0 0 0 0 0.8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.8 0 3.1 0 0 2.0 0 0 4.4 12.4 0 8.1 0.8 2.4 9.5 3.9 0 4.8 20.8 0.9 8.2 0.4 1.0 2.1 1.3 1.0 11.5 11.5 1.0 * Station 140 was added to the program in 1988. TABLE 4.C-3
AVERAGE MONTHLY CATCH (FISH PER HECTARE) OF LONGFIN
SMELT (ALL LIFE STAGES COMBINED) AT CDFW SOUTH BAY
OTTER TRAWL STATIONS*, 1980-1986
Month 101 102 103 104 105 106 107 108 Jan 28.2 14.6 1.3 8.0 10.4 4.5 48.6 392.6 Feb 74.4 5.7 2.5 37.1 55.1 4.9 214.9 42.3 Mar 876.0 0 0 0 0 2.0 24.6 7.3 Apr 8.2 8.6 5.9 0.9 3.1 4.5 0 6.1 May 11.3 1.9 2.0 27.4 9.0 0 0 1.8 Jun 15.6 0 0 1.8 0 0 3.8 7.2 Jul 0 0 0 0 0 1.1 1.0 0 Aug 0 0 0 0 0 4.8 0 0 Sep 5.4 0 0 0 0 8.0 0 0 Oct 0 0 0 0 2.2 17.4 0 6.3 Nov 3.8 4.7 1.0 0 0 0 0 3.8 Dec 30.3 8.2 1.4 10.4 17.4 35.9 63.2 110.6 Total 88.5 3.6 1.2 6.9 8.1 6.4 29.3 49.6 * Data courtesy of CDFW's San Francisco Bay Study and the Interagency Ecological Program for the San Francisco Estuary.