Tires: Unstable Materials For Artificial Reef Construction

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\u27s. 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. Keywords: southeast Florida, recycling, habitat restoration

Site-Dependent Differences in Artificial Reef Function: Implications for Coral Reef Restoration

There is an increasing use of artificial structure in coral reef restoration (for references, see Spieler et al., this volume). Often artificial reef structures are chosen for a restoration project simply because they were used elsewhere. However, it is questionable whether the results obtained at one restoration site can be extrapolated to another. In recent years, several studies have examined the effect of artificial reef site selection on formation of associated fish, algae, and/or invertebrate assemblages (Alevizon et al., 1985; Blinova et al., 1994; Bombace et al., 1994; Caley and St. John, 1996; Chang, 1985; Haughton and Aiken, 1989; Hixon and Beets, 1989; Jara and Cespedes, 1994; Kruer and Causey, 1992; Lozano-Alvarez et al., 1994; Moffitt et al., 1989; Relini et al., 1994; Sherman et al., 2000; Sherman et al., 1999; Sogard, 1989; Spieler, 1998; Tomascik, 1991). Although not designed specifically as coral reef restoration projects, the results of these studies lend insight into the problems of restoration. This paper is an overview of recent literature on site selection intended for resource managers interested in using artificial reefs in coral reef restoration. To that end, we re-examined the data from several studies comparing similar artificial reef structures at different sites

Artificial Substrate and Coral Reef Restoration: What Do We Need to Know to Know What We Need

To use artificial substrate effectively in coral reef restoration certain basic knowledge is required: (1) what is the artificial substrate expected to accomplish relative to the goals of the restoration effort and (2) what are the expected interactions of the selected substrate’s composition, texture, orientation, and design with the damaged environment and the biota of interest. Whereas the first point is usually clear, at least in general terms, the second is not. In this review, we examine: the functions of artificial substrate in restoration and some of the physical (i.e., composition; surface texture; color and chemistry; and design in terms of profile, shelter, shading, size and configuration, settlement attractants, and stability) and environmental factors (i.e., temperature, light sedimentation, surround biota, hydrodynamics, depth, and temporal effects) affecting these functions. We conclude that until substantial additional research is accomplished, the use of artificial substrate in coral reef restoration will remain a ‘best guess’ endeavor. Areas requiring additional research are identified and some potentially promising lines of inquiry are suggested

Development of Embryonic Gill Vasculature in the Yellow Stingray, Urobatis jamaicensis

Corrosion casting was utilized to examine the development of gill vasculature in embryonic yellow stingrays, Urobatis jamaicensis (formerly Urolophus jamaicensis). The most marked changes in vascular configuration of the gills occur in the earliest castable stages of gestation. These changes included development of afferent external gill filament vessels and progression from paired dorsal aortae to a single fused dorsal aorta. Internal gill vasculature was found to nearly match that of an adult by the time the external gill filaments had fully regressed and yolk sac had been exhausted (\u3e47 mm disc width). Examination of embryo casts also revealed characteristics of the branchial vasculature not previously reported in adult specimens. These include the presence of pre-lamellar sphincters, intertrematic branches, afferent distributing arteries, which supply blood to many afferent filament arteries resulting in greater interconnection of the filaments, and observation that the afferent branchial artery in the first hemibranch supplies blood directly to afferent filament arteries on the dorsal half of this arch

Correlation effects in sequential energy branching: an exact model of the Fano statistics

Correlation effects in in the fluctuation of the number of particles in the process of energy branching by sequential impact ionizations are studied using an exactly soluble model of random parking on a line. The Fano factor F calculated in an uncorrelated final-state "shot-glass" model does not give an accurate answer even with the exact gap-distribution statistics. Allowing for the nearest-neighbor correlation effects gives a correction to F that brings F very close to its exact value. We discuss the implications of our results for energy resolution of semiconductor gamma detectors, where the value of F is of the essence. We argue that F is controlled by correlations in the cascade energy branching process and hence the widely used final-state model estimates are not reliable -- especially in the practically relevant cases when the energy branching is terminated by competition between impact ionization and phonon emission.Comment: 11 pages, 4 figures. Submitted to Physical Review

Hypothesis-based Restoration Study For Mitigation of a Damaged SE Florida Coral Reef: A Work in Progress

The United States Submarine Memphis (Figure 1) ran aground in approximately 10 meter depth on a coral reef off southeast Florida (Figure 2) February 25, 1993. Extensive physical damage to the reef substrate and injury to the coral community were attributed to the initial grounding and subsequent attempts to free the submarine from the impacted reef (Figures 3 and 4). The impact of the grounding was assessed, and the area of damage was determined through field and photographic studies. An impacted area of 2,310 m2 was assessed with 1,205 m2 having been totally destroyed (Figures 3 and 4). In 1997, the State of Florida was awarded a settlement of $750,000 by the Federal government for environmental damages caused by the submarine grounding. A plan to perform hypothesis testing of restoration techniques was developed and initiated. Using artificial reefs as experimental platforms, we are examining three restoration strategies: 1) the potential of enhancing coral recruitment through the use of coral larval attractants, 2) the effect of reef structure on the associated fish assemblages, and 3) the interaction between fish assemblages and coral recruitment and survival

The Yellow Stingray, Urobatis jamaicensis (Chondrichthyes Urotrygonidae): A Synoptic Review

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

Marine Biological Monitoring in Broward County, Florida: Year 2 Annual Report

A study has been undertaken to monitor Broward County, Florida (southeast Florida) coral communities, reef fish assemblages and sedimentation rates in relation to possible effects from a proposed extensive beach renourishment (restoration) project. Coral communities and reef fish assemblages will be monitored at a total of 23 stations distributed offshore Broward County. This monitoring effort will characterize and quantify populations of scleractinian (stony) corals, octocorallian (gorgonian) corals, sponges, and reef fishes. In addition, sediment traps located at each station will be sampled and analyzed. This document reports the data collected during the second year of this project. Coral communities and fish assemblages were monitored at each of the 23 sites between September and October 2001. In addition, sedimentation analysis for the January, March, May, July and September 2001 collections were conducted. For September/October 2001, mean (± 1 S.D.) stony coral density for the 23 sites was 2.62 ± 1.85 colonies/m2. Mean stony coral coverage was 2.39 ± 3.96%. Mean gorgonian density was 7.91 ± 8.01 colonies/m2 and mean sponge density was 14.09 ± 6.93 colonies/m2. First Reef sites had greater mean stony coral coverage but lower gorgonian and sponge density than Second and Third Reef sites. First Reef coral cover was much lower than the Third Reef when the First reef site, FTL4, was removed from the analysis. FTL4 had much greater stony coral cover than the mean cover for the remaining First Reef sites (19.95% compared to 1.45%). Shannon-Weaver Diversity Indices performed on the overall transect data resulted in values of 1.45 ± 0.53 and 1.72 ± 0.44 for cover and number of species respectively. Overall evenness was 0.77 ± 0.14 for number of species and 0.64 ± 0.21 for cover. There was no significant difference determined between the January/February 2001 site visit data and the September/October 2001 site visit data for mean stony coral density and cover. Mean octocoral density also did not differ significantly between these site visits, but mean sponge density was significantly less in September/October 2001 than in January/February 2001. Stony coral density, stony coral coverage, gorgonian density and sponge density data collected from the 18 monitoring sites established in 1997 and visited yearly from 1997 to 1999 were analyzed. No significant difference in yearly mean stony coral density, mean stony coral cover and mean gorgonian density was determined. Mean sponge density did show significant differences with 1998 sponge density greater than 1997. Trends in fish density were similar to those trends identified within the coral community transects. The greatest density of fishes occurs on the Third Reef followed by the First and Second. A difference in richness was seen amongst the three Reefs with the First Reef having the lowest number of species. The differences noted in abundance, density, and richness between the data collected in January/February 2001 and in September/October 2001 confirm previous reports of temporal differences in the fish assemblage offshore Broward County (Spieler 1998). The First Reef had a statistically higher rate of sedimentation than both the Second and Third Reefs when data from January-September 2001 were pooled. Pooled site data showed that January 2001 and May 2001 samples had the greatest sedimentation rates. The grain size for sites on the Third Reef was significantly smaller than both the First and Second Reefs. When site data were pooled, January 2001 had a significantly larger mean grain size than the other four sampling intervals in 2001. Data collected and analyses completed during this monitoring project will be used to help evaluate effects from the proposed beach renourishment project

Presence of Juvenile Blackfin Snapper, Lutjanus buccanella, and Snowy Grouper, Epinephelus niveatus, on Shallow-water Artificial Reefs

The inshore environment of Broward County, Florida consists of three reef tracts, each separated by sand substrate, running parallel to the coastline in sequentially deeper water. A wide variety of artificial reef designs have been deployed in Broward County, many lying in sand flats between the reeftracts. From 1995 through 2002, over 1,100 visual fish censuses (predominantly point-counts) were completed on the three natural reeftracts in water depths from 3 m to 30 m and over 1,100 censuses were done on artificial reefs at depths of 7 m to 23 m. Curiously, the juvenile stages of two deeper-water species of the snapper/grouper complex, the blackfin snapper (Lutjanus buccanella) and the snowy grouper (Epinephelus niveatus), appear to prefer artificial reefs located in the sand flat separating the second and third reeftracts to nearby natural reef areas. Five hundred and forty blackfin snapper have been recorded in 64 visual censuses and nine snowy grouper have been observed in seven counts on artificial reefs. Despite the large volume of visual census data collected thus far, these two species have never been recorded on nearby natural reef tracts. The reasons for this unanticipated observation is unclear but it provides an excellent launch-point for an examination of juvenile habitat requirements, natural availability of these requirements, and the potential for artificial substrate to be used in managing these species