. Artificial reef design: void space, complexity, and attractants. -ICES Journal of Marine Science, 59: S196-S200.The potential for enhancing fish abundance, species richness, and biomass on artificial reefs was examined by attaching floating attractants and manipulating structural complexity of small concrete reefs each approximately 1.3 m in diameter, 1 m high. Experimental design consisted of a comparison of fish assemblages among three treatments (10 replicate, hemisphere-shaped reefs each): 10-m floating line attached (Streamer); concrete block in the central void space (Block); and no floating line or concrete block (Control). Reefs were deployed on sandy substrate at 20-m depth off Fort Lauderdale, Florida, USA. Divers recorded fish census data on slates 18 times over 24 months. Species composition, numbers of individuals per species, and estimated total length (TL; by size class: <5, 5-10, 10-20, and >20 cm) for all fishes within 1 m of each reef were recorded. Size classes were used to calculate fish biomass. There was a significant difference among treatments. Block reefs had higher numbers of individuals, species, and biomass than Streamer or Control reefs (p<0.05). With one exception, Streamer reefs did not differ from Controls for any of the parameters investigated (p>0.05). These results highlight the importance of structural complexity in artificial reefs designed to enhance fish recruitment, aggregation, and diversity.

Small concrete artificial reef modules (hemisphere‐shaped, approximately 1.3 m diameter, 1 m high) were placed at two sites, eight modules per site. The sites were in 7 m and 21 m of water, 1.6 km apart, off the coast of southeast Florida, USA. The reefs were censused monthly for fish over a 19‐month period. Species, number of fish, and estimated total length of each individual were recorded by divers using SCUBA. After the monthly census, all fish were removed from the reefs with a piscicide. A total of 88 species were recorded in the study, with significantly greater diversity on the deep reefs (monthly mean of 7.6 versus 3.0 shallow, P < 0.001, anova). There were also significantly more biomass (calculated from length), and more large fish (>5 cm) on the reefs at 21 m than at 7 m (P < 0.001). There were more small fish at the shallow site (P < 0.05). Although it is not clear what variable(s) associated with the two depths is responsible for the differences, these results highlight the potential differences in artificial reef and ambient environment interactions within a localized area.

Artificial reefs of varied materials have been deployed worldwide to acquire large and diverse fish assemblages for both commercial and sport fishers, and SCUBA divers. Beginning in 1967, environmental resource managers and local fishers initiated a project to build an artificial reef using banded, but unballasted, waste automobile and truck tires offshore Broward County, Florida, USA. Estimates of the number of tires placed offshore range between 1,000,000-2,000,000. Since deployment, storm events and ocean currents have caused the bands to give way and the break-up of the reef. Over the years, many tires have washed ashore onto recreational beach areas. Tires that remain in the water continue to move with wave action and currents. Many of these remaining tires have already been forced up against the offshore edge of natural reef with numbers at individual sites estimated in the 100,000's. The objectives of this project were to examine the feasibility of removing the tires as well as gain subjective insight into the impact of the tires on natural habitat. Sixteen hundred tires were removed from the reef edge and recycled. The potential problems arising from the use of tires in artificial reef construction were apparent. Natural reef fauna was broken and buried providing a seascape resembling a junkyard. The shortsighted use of unstable material to construct artificial reefs is an issue facing many coastal areas. Disturbance of this unstable material has futher added to other natural and anthropogenic stresses suffered by the coral reef systems and the wildlife they support. Clearly, unstable materials, such as tires, are not suitable for artificial reef construction. If already deployed, tires should be removed to prevent physical damage to the natural habitat and reduce the related negative biological impacts, in turn, limiting economic loss to local communities benefiting from use of the natural reef.

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The yellow stingray, Urobatis jamaicensis (Cuvier) has been the subject of a multitude of diverse studies on its natural history, morphology, and physiology. We have attempted here to briefly review all the studies on U. jamaicensis both published and unpublished with the goal of providing comparative information for researchers working on related species as well as to highlight areas of research requiring further investigation in this one.