CalCOFI Reports, Vol. 27, 1986 - California Cooperative Oceanic ...

LAVENBERG ET AL.: SOUTHERN CALIFORNIA NEARSHORE ICHTHYOPLANKTONCalCOFI Rep., Vol. XXVII, 1986TABLE 1Coordinates of Stations Occupied During 1982-1984Transect Station N. Latitude W. Longitude(CalCOFI line) (m)Ormond Beach 8 34'07.5' 119"16.6'(84.7) 15 34"07.0' 119"11.0'22 34'06.6' 119'1 1.7'36 34'06.0' 119"12.8'75 34O04.5 ' 119°11.9'Playa del Rey 8 33'57.0' 1 W27. I '(86.8) 15 33'57.0' 118'27.9'22 33'56.9' 118'28.6'36 33'57.0' 118'30.1 '75 33T7.2' 118"34.0'Seal Beach 8 33"42.4' 118'04.3'(88.4) 15 33O41.2' 118"04.8'22 33'39.6' 118"05.1'36 33O37.3' 118'05.7'75 33'34.8' 118"08.9'San Onofre 8 33'21.7' 117'33.8'(90.9) 15 33'20.9' 117"34.1'22 33'20.4' 117'34.7'36 33'19.9' 117'35.0'75 33'1 8.5' 117'35.6'(Schlotterbeck and Connally 1982; Barnett et al.1984). Net retrieval rates were about twice thoseemployed from August 1979 to July 1980 (Phase I1sampling as described by Brewer and Smith 1982),but replicates were not combined, i.e., the nets filteredabout 6-8 m3 of water per meter of depth. Proceduresand assumptions for processing fish eggs and larvaewere the same as those described by Brewer and Smith(1982), except that no aliquots were taken. Sampleswere 100% sorted from either the port or starboard sideof the bongo plankton sampler.Species of the genus Parafabrux are not separable atall stages (Butler et al. 1982) and have therefore beentreated together as a single taxon. However, progresshas been made in the identification of Paralichthyscafifornicus larvae', and the abundance of this speciesas reported here is for the first time uncontaminatedwith that of the similar Xystreurys fiolepis.Areal EstimatesThe transects sampled during this project areassumed to be representative of the coastal zone shorewardof 75 m in the Southern California Bight. Thus anestimate of the magnitude of ichthyoplankton populationsin the narrow band of nearshore waters along thecoast can be based on data from these transects.'Carlson-Oda, D. Description of the early life hlstory of the California halibut,Purulichrh~s culifornicus, with comparisons to other members of the familyBothidae. Abstract presented at CalCOFI annual conference, 1985.TABLE 2Dates of Collection, Cruises 1-52Cruise no. Month and year Cruise no. Month and yearMonthly programs ( 10 transects) (20 transects)1 June 1978 15 August 19792 July 1978 16 September 19793* August 1978 17 October 19794 September 1978 18 November 19795 October 1978 19 December 19796* November 1978 20 January 19807 December 1978 21 February 19808 January 1979 22 March 19809* February 1979 23 April 1980IO March 1979 24 May 198011 April 1979 25 June 198012* May 1979 26 July 198013* June 197914* July 1979Bimonthly program (4 transects)34 February 1982 (January 30)35 March-May 1982 (31-11)36 June 198237 August 198238 October 198239 December 198240 February 198341** March 198342 April 198343 June 198344 August 198345 October 198346 December 198347 February 198448 April 198449 June 198450 August 198451 October 198452 December 1984*Collections not worked up**Nonstandard cruiseThe Apple Graphics Tablet was used to determinethe areas bounded by depth contours on NationalOcean Survey bathymetric maps (nos. 1306N- 15, - 16,-19, and -20). The maps were juxtaposed, and acomposite made that had 10-m intervals out to 100 m.The 75-m contour was drawn in (Figure 1). We drewthe 20 sampling transects approximately perpendicularto the 75-m contour, then drew lines perpendicularfrom the midpoints between the intersections. Thelatter set of lines defined 20 blocks, centered on thetransects, on which all areal determinations werebased. Block 1 (CalCOFI line 80.8 off Cojo Bay) wasbounded on the northwest by a line extending fromPoint Conception perpendicular to the 75-m contour,and block 20 (CalCOFI line 94.7 off Imperial Beach)55