settlement is to a large degree passive and succeeds only because currents 

 carry larvae over reefs, then the process can be considered somewhat stochastic; 

 if, however, searching and testing behaviors, such as vertical movements in the 

 water column (as observed in many invertebrate reef plankters; see McFarland 

 and Ogden, this volume, for specific references), are widely utilized by larvae 

 to identify suitable substrates on which to settle, then recruitment can be 

 considered as an active determined process. However, even if fish larvae do 

 actively 'search' for specific substrate as they settle from the plankton, or 

 soon after, their success in establishing themselves can be negatively affected 

 by the presence of previously settled juveniles (Shulman, et a! . , 1983). As a 

 result, even if the act of settlement is deterministic for each larva, the 

 overall success of individual recruits is infused with a large element of 

 chance (e.g., being in a current that favors transport to native habitat, 

 arriving in a region of native habitat at the appropriate time of day to avoid 

 predation, actually finding an appropriate and 'empty' settlement site within 

 the native habitat). In a very real sense, therefore, settlement can be viewed 

 as partly determined and partly stochastic. Because we remain largely ignorant 

 of the details of the settlement process, and because recruitment is central to 

 understanding coral reef fish community structure (see Helfman, 1978, for review), 

 generalizations about the proximal and ultimate causes of the high species diver- 

 sity of fishes associated with coral reefs remain, at best, first approximations. 



Although innumerable problems require solution to understand recruitment 

 dynamics in coral reef organisms, it was generally concluded that rapid progress 

 would result by focusing attention on four general areas: (1) the timing and 

 dynamics of reproduction: where, when, and how often; (2) investigation of the 

 fine scale horizontal, vertical, and diel distribution of larvae over a time 

 frame that spans reproduction through recruitment; (3) coincident fine scale 

 measures of local current regimes (at varied depths); and (4) descriptive and 

 experimental investigations of the behaviors of larval coral reef organisms. 

 Furthermore, it is not enough to study only one species, although individual 

 researchers will be hard pressed to examine more than one at a time. 



Because of the necessary broad scope of recruitment studies, the research 

 will involve planktologists , fish biologists, invertebrate biologists, 

 behaviorists, and physical oceanographers. As a result, interdisciplinary 

 collaborations will be a requirement in understanding and solving tropical 

 recruitment processes. 



LITERATURE CITED 



Blaxter, J. H. S., and J. R. Hunter. 1982. "The Biology of the Clupeoid 

 Fishes." Adv. Mar. Biol. 20:1-223. 



Brothers, E. B., C. P. Matthews, and R. Lasker. 1976. "Daily Growth Increments 

 in Otoliths From Larval and Adult Fishes." Fish. Bull . 74:1-8. 



Brothers, E. B., and W. N. McFarland. 1981. "Correlations Between Otolith 

 Microstructure, Growth, and Life History Transitions in Newly Recruited 

 French Grunts ( Haemulon f lavol ineatum (Desmarest), Haemulidae). " _I_n: R. 

 Lasker and J. Blaxter (eds.), Early Life History of Fish, H_. Rapp. P-V. 

 Reun. Cons. Int. Explor. Mer. 178:369-374. 



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