In 6 bays of St. Croix, U.S. Virgin Islands, small (<3 cm), medium (3-5cm), and large (<5cm) fishes in lagoons and associated bank-barrier back-reefs were surveyed at 4-month intervals (in February, June, and October) from June 1999 through February 2001. Most recruitment took place during the summer. Overall, densities of small fishes were higher in lagoon patch reef and/or lagoon rubble than in the back-reef, and this indication that these lagoon habitats may be essential for fish populations is born out by substantially higher levels of recruitment of several species (but not all species) to these lagoon habitats than back-reefs. Differences among bays in attracting settling fishes and maintaining juveniles are evidently not influenced strongly by oceanographic processes. Preliminary analysis of experimental augmentation of lagoonal patch reefs suggests (1) that, overall, small and medium fishes use the artificial and natural patch reefs in a similar manner, thus indicating our habitat augmentation approach was appropriate; and (2) that habitat augmentation had no effect on densities of large fishes in adjacent back-reefs (compared to control sites). However, further collection of data is required for conclusive interpretation. Adventitious research associated with this project indicates:(1) Hurricane Lenny (November 1999) had little evident impact on the fishes under study, (2) long-spine sea urchins on St. Croix have begun to recover from the die-off of 1983-84, and (3) tagging juvenile fishes in nursery habitats is a feasible method for following fishes through ontogenetic habitat shifts.