Polovina et al.; Application of satellite altimetry to simulate transport dynamics of Panulirus marginatus 



141 



35'N 



C Necker 



35'N 



30'N 



25'N 



20'N 



15'N 



10'N 



35'N 



30'N 



25'N 



20'N 



15'N 



10'N 





30'N 



25'N 



20'N 



15'N 



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165'E 170'E 175'E 180" 175'W 170'W 165'W 160'W 155'W 150'W 145'W 



35'N 



30'N 



25'N 



20'N 



15'N 



10'N 



165'E 170'E 175'E 180' 175'W 170'W 165'W 160'W 155'W 150'W 145'W 



Figure 7 (continued) 



west to the southeast to Necker and then southwest. 

 Necker's persistent spiny lobster population and fish- 

 ery appear to be the result of its location where it both 

 receives larvae from banks to the northwest and south- 

 east and also has a high retention of its own larvae. 

 Only 670 km to the northwest, Maro's retention rate 

 was only about one-half that of Necker, and although 

 it contributed larvae to Necker, it did not receive any 

 substantial contribution of larvae from Necker. This 

 finding explains why recruitment at Maro remained 

 depressed once the spawning biomass at Maro and 

 other banks to the northwest were depleted, even 

 though there was a substantial spawning biomass at 

 Necker. However, it raises questions. Why were Maro 

 and other northern banks so productive during the 



1980s? Was the transport regime in the 1980s differ- 

 ent, so that Maro and northern banks lost fewer larvae 

 to the southeast and perhaps even received consider- 

 able larvae from Necker? Alternatively, because the fish- 

 ery began only in the late 1970s, was recruitment al- 

 ways so weak at Maro and at other northern banks 

 that the collapse at the end of the 1980s represented 

 simply a response to overfishing an unexploited popu- 

 lation? Although we cannot answer these questions, 

 the results suggest that if the transport regime observed 

 during 1993-96 persists, increased recruitment to Maro 

 and other banks to the northwest may require an in- 

 crease in the spawning population at Maro and other 

 northern banks. Research on a similar species of spiny 

 lobster, P. argus, in the Bahamas found physical trans- 



