666 



Fishery Bulletin 102(4) 



and 720, although areas of high catch, do not appear on 

 the satellite composite because the mainland shore was 

 excluded from light detection. Further, much activity 

 was evident around Santa Barbara Island (block 765). 

 Although this block represented 4.0 million kg (18th 

 out of the 127 blocks), it did not rank highly enough for 

 inclusion in Fig. IB. 



Analysis of temporal trends in the fishery showed 

 peaks in landed catch for the bight in the fall and 

 winter quarters (Oct-Dec and Jan-Mar, respectively; 

 Fig. 3A). There was a near absence of catch during 



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1992 1993 1994 1995 1996 1997 1998 1999 2000 



Quarter 



Figure 3 



Time series of market squid fishery data in Southern California 

 Bight, by calendar quarter (Jul-Sep 1992 to Jan-Mar 2000). 

 The Jan-Mar quarters are marked by dashed vertical lines. 

 (A) Landings are in kg (blocks 651-896, 1032-1035). (B) Mean 

 ±SE nightly fishing effort, in estimated number of squid vessels. 

 (C) Landings per unit of effort (LPUEl: summed landings (kg) 

 on satellite nights were divided by summed effort (estimated 

 number of squid vessels) on the corresponding nights. 



most of 1997-98 (Fig. 3A), which corresponded to the 

 strong El Nino event during this period (Fig. 4). Effort 

 data revealed surges in the Oct-Dec quarters before 

 the 1997-98 El Nino (Fig. 3B). The Oct-Dec quarter 

 of 1998 signalled a resumption of fishing effort follow- 

 ing El Nino, but effort levels for 1999 and early 2000 

 were lower than pre-El Nino levels. Interestingly, squid 

 abundance, as measured by landings per unit of effort 

 (LPUE), showed a rapid increase from the El Nino lows, 

 and squid abundance for 1999-2000 reached the high- 

 est values of the time series (Fig. 3C). 



Analysis of boat locations along the Channel 

 Islands revealed a shift over the course of the 

 fishing season. Compiling the satellite data to 

 yield composite images in multiyear sets, we 

 found that fishing activity in October consis- 

 tently included the north shore of Santa Cruz 

 Island (Fig. 5, A,C,E). In contrast, fishing ac- 

 tivity in March showed considerable reduction 

 along the north side of Santa Cruz Is., but activ- 

 ity continued along the island's southern shore 

 (Fig. 5, B,D,F). Composite images for December 

 and January were also examined for all of the 

 multiyear sets. December marked a transitional 

 stage from the activity in October to reduction 

 of fishing in March along the northern shores. 

 In all multiyear sets, the December lights along 

 northern Santa Cruz Island were more scat- 

 tered and less dense than those in October. 

 January images were very similar to those for 

 March. Although data from March 1993-95 in- 

 dicated little fishing activity, a composite image 

 for January 1993-95 was very similar to that 

 for March 1999-2000: light banks occurred off 

 southern Santa Cruz, southeastern Santa Rosa, 

 and around Anacapa, but were virtually absent 

 from northern Santa Cruz and Santa Rosa. 



Water temperatures around Santa Cruz Is- 

 land did not consistently differ between north- 

 ern and southern waters. March sea surface 

 temperatures, measured by satellite, were very 

 similar for the island's northern and south- 

 ern shores (Table 2). April sea surface tem- 

 peratures, measured at CalCOFI stations, were 

 slightly warmer to the northeast of the island 

 (Table 2). Temperatures at 75 meters, however, 

 were nearly identical for the two CalCOFI sta- 

 tions (Table 2). 



Discussion 



The satellite images and landings data corrobo- 

 rated spatial and temporal patterns of fishing 

 activity for the market squid. For the period 

 1992-2000, both data sets indicated intense 

 harvesting along the Channel Islands of Santa 

 Rosa, Santa Cruz, Anacapa, and Santa Cata- 

 lina. The satellite images captured additional 

 information, such as fishing activity being 



