ABSTRACT
The juvenile stages of most reef ‚shes are dif‚cult to sample due to cryptic habitat associations with complex reef habitats. Traditional methods such as trawls are usually inef‚cient even over reef habitats with relatively small (<1 m) relief. Arti‚cial reefs offer an alternative method for the study of juvenile reef ‚shes as this information is essential in the effective management of benthic ‚sheries. If juvenile reef ‚shes can be attracted to arti‚cial reefs, it is possible to use arti‚cial reefs as part of the sampling method to study these important early stages. For example, the juvenile life stage of the recreationally and commercially important red snapper, Lutjanus campechanus (Poey 1860), from the northern Gulf of Mexico has received considerable attention because high mortalities during these stages are associated with later year classes. However, most abundance estimates of age 0-1 red snapper are based on trawl surveys, but as shown here, juvenile red snapper quickly become associated with reef structure during their ‚rst month or two of life, suggesting that juvenile abundance estimates using trawls may have both low precision and accuracy. Consistently high densities over several years of new recruits to arti‚cial reefs (even in years of low adult red snapper abundance) and the lack of any increase in new recruit densities (even after signi‚cant shrimp trawl bycatch reduction, in recent years) indicates that early postsettlement processes in¦uence subsequent red snapper year class strength. These conclusions are based on diver surveys of arti‚cial
CONTENTS
Abstract ............................................................................................................................................ 31 Introduction ...................................................................................................................................... 32 Methods ........................................................................................................................................... 33 Results ..............................................................................................................................................36 Discussion ........................................................................................................................................ 37
Early Recruitment to Structured Habitat .................................................................................... 37 Postrecruitment Population Regulation ......................................................................................40 Future Use of Arti‚cial Reefs in Fishery Management Questions ............................................. 41
Acknowledgments ............................................................................................................................ 42 References ........................................................................................................................................ 43
reefs as opposed to traditional trawl sampling. The increased use of sampling juvenile reef ‚shes with arti‚cial reefs as the “sampling tool” could provide new insight into the ecology and management of important reef ‚sh species.
