ROTHLISBERG and MILLER: LARVAL I'AXDAI.l <S JORDAS1 OFF OREGON 



quent upwelling, reaching deeper water over habitat 

 suitable to settling. 



Application to all years uniformly of Gotshall's 

 (1969, 1972) instantaneous mortality for juvenile P. 

 jordani on the bottom ignores the certain variation in 

 that mortality. Despite this limitation, the estimate of 

 larval survival derived from the analysis was similar 

 to estimates from our 2 yr of intensive plankton sam- 

 pling. We are aware of the dangers of a comparison 

 based on only two spawning seasons, but the com- 

 parison is in the correct direction, and it is all we have. 

 Although there are limitations, comparison of egg 

 numbers with numbers of first fishery recruits shows 

 promise for identifying conditions critical in es- 

 tablishing year class strength. Higher resolution 

 could be obtained if annual estimates of early benthic 

 mortality were made, perhaps using the Pacific hake, 

 Merluccius productus, as a biological sampler. 



ACKNOWLEDGMENTS 



This study was part of the Early Life History Pro- 

 gram conceived and directed by J. J. Gonor, W. 

 McNeil, W. G. Pearcy, and I. Pratt. Additional dis- 

 cussions and manuscript reviews were received from 

 C. Bayne, R. Olson, D. Staples, and C. Warren. Cap- 

 tain T. LaScota and the crew of the RV Cayuse, along 

 with L. Brixius, M. Halsey, R. G. Lough, and W. T. 

 Peterson, gave valuable assistance with collection of 

 samples at sea. From the Oregon Department of 

 Fisheries and Wildlife, J. Robinson gave insight into 

 the biology of P. jordani and provided unpublished 

 survey data, and M. Hosie initiated and supervised 

 the drift bottle program. W. Gilbert assisted with 

 analysis of drift bottle and wind data. N. Hall and I. 

 Somers gave valuable assistance with manuscript 

 preparation. This work was sponsored (in part) by 

 the Oregon State University Sea Grant Program, 

 supported by NOAA Office of Sea Grant, U.S. 

 Department of Commerce, under Grant No. 04-3- 

 158-4. 



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471 



