Abstract.- Research and com- 

 mercial trapping data show variation 

 in recruitment to the fishery for 

 spiny lobster Panulirus marginahis 

 at Maro Reef, relative to Necker 

 Island which is 670 km to the south- 

 east. Recruitment to the fishery at 

 Maro Reef is shown to be highly cor- 

 related with the difference in sea 

 level 4 years earlier between French 

 Frigate Shoals and Midway Islands. 

 Geosat altimeter data indicate that 

 the relative sea level between French 

 Frigate Shoals and Midway is an in- 

 dicator of the strength of the Sub- 

 tropical Counter Current. Mechan- 

 isms linking the Subtropical Counter 

 Current with larval advection and 

 survival are discussed. The sea level 

 index provides a forecast of recruit- 

 ment 4 years later to the fishery at 

 Maro Reef. 



Variability In spiny lobster 

 Panulirus marginatus recruitment 

 and sea level In the Northwestern 

 Ha\A/allan Islands* 



Jeffrey J. Polovina 



Honolulu Laboratory, Southwest Fisheries Science Center 



National Marine Fisheries Service. NOAA 



2570 Dole Street, Honolulu, Hawaii 96822-2396 

 Joint Institute of Marine and Atmospheric Research (JIMAR) 



University of Hawaii, Honolulu. Hawaii 96822 

 Department of Oceanography. School of Ocean and Earth Science and Technology 



University of Hawaii, Honolulu, Hawaii 96822 



Gary T. Mitchum 



Joint Institute of Marine and Atmospheric Research (JIMAR) 



University of Hawaii, Honolulu, Hawaii 96822 

 Department of Oceanography, School of Ocean and Earth Science and Technology 



University of Hawaii, Honolulu, Hawaii 96822 



Significant correlations between com- 

 mercial landings or recruitment esti- 

 mates and one or more environmen- 

 tal indices are commonly reported in 

 the fisheries literature, but few have 

 served as accurate predictors of fu- 

 ture population levels (Drinkwater 

 and Myers 1987). However, such cor- 

 relations can lead to the formulation 

 or support of hypotheses regarding 

 the factors responsible for population 

 changes. For example, an inverse 

 correlation between the survival of 

 Pacific mackerel Scomber japonicus 

 to age 1 and the strength of the Cali- 

 fornia Current, and the lack of corre- 

 lation between survival and plankton 

 biomass, have been offered as evi- 

 dence that advection, rather than 

 starvation, controlled survival of the 

 planktonic stages of this species 

 (Sinclair et al. 1985). 



Correlative studies on lobsters sug- 

 gest that population size results from 

 changes in survival and advection at 

 the larval stage, but in at least one 



Manuscript accepted 20 May 1992. 

 Fishery Bulletin, U.S. 90:483-493 (1992). 



' Contribution 2820 of the School of Ocean and 

 Earth Science and Technology. University of 

 Hawaii; JIMAR Contribution 91-0243. 



instance, density-dependent mechan- 

 isms after postsettlement may damp- 

 en this variation (Pollock 1986). Fluc- 

 tuations in sea-surface temperature 

 appear to result in changes in larval 

 survival and catches 6 years later for 

 the clawed lobster Homarus ameri- 

 canus in Maine (Fogarty 1988). Vari- 

 ation in the strength of the Leeuwin 

 Current, which may be linked to El 

 Nino Southern Oscillation (ENSO) 

 events, is suggested as a cause of 

 variation in the number of larvae re- 

 turned to the coast and subsequent 

 recruitment to the fishery for the 

 western rock lobster Panulirus 

 argus (Pearce and Phillips 1988). 

 Changes in recruitment levels of the 

 California spiny lobster P. interrup- 

 tus to the northern portion of its 

 habitat may be episodic, influenced 

 by large-scale, interannual El Nino 

 events (Pringle 1986). Variation in 

 postlarval recruitment in the South 

 African rock lobster Jasus lalandii 

 is thought to arise from changes in 

 the paths and velocities of extensive 

 offshore currents, which eventually 

 return larvae to the coast. However, 

 density-dependent phenomena influ- 



483 



