Differences in the structures of fish assemblages inThalassia testudinum beds in Guadeloupe,French West Indies,and their ecological significance

The structures of fish assemblages in twoThalassia testudinum beds in Guadeloupe, French West Indies, one adjacent to mangroves and the other adjacent to coral reefs, were compared between January 1983 and May 1984. The aim of the study was to compare the influences of mangroves and coral reefs on the utilization of seagrass beds by fishes through examination of species composition, catch rate, size of fishes and temporal changes. The two fish assemblages were similar in terms of the number of species they had in common (nearly 44% of the total number of species collected) and the great abundance of juveniles. They both comprised species that usually inhabit other habitats, i.e., estuaries, open waters or coral reefs. Estuary-associated species (e.g. Gerreidae) were the most abundant species in the seagrass bed near the mangroves, while small pelagic species (e.g. Clupeidae) were the most abundant species in the seagrass bed near the coral reefs. The seagrass bed near the mangroves was preferentially utilized as a nursery area by small juveniles of various species (e.g. Clupeidae, Sparidae, Gerreidae, and at least one coral reef species,Ocyurus chrysurus). The abundance of these species varied frequently, suggesting successive arrivals and departures of juveniles over time. The seagrass bed near the coral reefs was characteristically utilized by fishes that are more able to avoid predation, i.e., fishes that forage over seagrass beds at night and shelter in or near the coral reefs during the day (large juveniles of coral reef species and adults of schooling pelagic species, respectively). The constant migrations of these fishes between the coral reefs and seagrass beds explained the relative stability of the structure of the fish assemblage in the seagrass bed over time. Thus, the two seagrass beds were not equivalent habitats for fishes. The distinct ecological influences of the mangroves (as a nursery for small juveniles) and coral reefs (as a shelter for larger fishes) on the nearby seagrass beds was clearly reflected by the distinct utilizations of these seagrass beds by fishes.     

The behavior of heterotypic resting schools of juvenile grunts (Pomadasyidae)

Resting schools of juvenile grunts (less than 12 cm length), composed primarily of Haemulon flavolineatum and H. plumieri, were studied from 1972 to 1976 on a series of patch reefs surrounded by seagrass beds on the northeast coast of St. Croix, U.S. Virgin Islands. Juvenile grunts form large inactive multispecies schools in reef areas by day. Repeated censuses over several years reveal that certain parts of the reef, particularly those with large formations of the corals Porites porites and Acropora palmata, are traditional schooling areas. When the fishes reach a size of about 15 cm, the H. plumieri form homotypic schools which roam the patch reefs but are no longer associated with particular formations of coral. In contrast, larger H. flavolineatum are uncommon on the patch reefs and they may move offshore to deeper water. The schools of juvenile grunts migrate some distance away (often 100 to 300 m) into seagrass-covered areas to feed on invertebrates at dusk each day. The routes which are followed into the seagrass beds are precise and persist over years. At dawn the grunts return to the reef on the same routes. Mass marking and release experiments show that juvenile grunts will move over long distances (approximately 3 km) to reach a home reef.     

Resource use by five sympatric parrotfishes in the San Blas Archipelago,Panama

Resource use by five sympatric species of parrotfish was quantified in the San Blas Archipelago of the Republic of Panama from March to August 1987. Detailed observations of parrotfishes on patch reefs and surrounding seagrass beds showed that they partition resources with respect to habitat, food and size, but not time. Although parrotfishes shared resources, the proportions of each resource used differed significantly among species. Scarus iserti (Bloch) scraped filamentous microalgae that grew from eroded coral pavement on lower slopes of patch reefs and in halos, the area of sparse vegetation surrounding reefs. Sparisoma viride (Bonnaterre) foraged on upper slopes of patch reefs where they mostly took bites from dead coral and associated algae. S. aurofrenatum (Cuvier and Valenciennes) had the broadest diet, which consisted mostly of seagrasses and macro- and microalgae that were attached to dead coral on lower reef slopes and in halos. Although S. chrysopterum (Bloch and Schneider) commonly occurred on patch reefs, it primarily foraged in seagrass beds that surround them. S. rubripinne (Cuvier and Valenciennes) was distributed most widely, ranging from seagrass beds to reef crests, where it took bites from seagrasses, dead coral and macroalgae. Juveniles of all species occurred on lower slopes or in halos where they scraped filamentous microalgae from coral pavement. As they matured, parrotfishes moved into other habitats changing access to different types of food. All of these parrotfishes fed throughout the daytime, and resource use did not differ between morning and afternoon.     

A test of the senses: fish select novel habitats by responding to multiple cues

Habitat-specific cues play an important role in orientation for animals that move through a mosaic of habitats. Environmental cues can be imprinted upon during early life stages to guide later return to adult habitats, yet many species must orient toward suitable habitats without previous experience of the habitat. It is hypothesized that multiple sensory cues may enable animals to differentiate between habitats in a sequential order relevant to the spatial scales over which the different types of information are conveyed, but previous research, especially for marine organisms, has mainly focused on the use of single cues in isolation. In this study, we investigated novel habitat selection through the use of three different sensory modalities (hearing, vision, and olfaction). Our model species, the French grunt, Haemulon flavolineatum, is a mangrove/seagrass-associated reef fish species that makes several habitat transitions during early life. Using several in situ and ex situ experiments, we tested the response of fish toward auditory, olfactory, and visual cues from four different habitats (seagrass beds, mangroves, rubble, and coral reef). We identified receptivity to multiple sensory cues during the same life phase, and found that different cues induced different reactions toward the same habitat. For example, early-juvenile fish only responded to sound from coral reefs and to chemical cues from mangroves/seagrass beds, while visual cues of conspecifics overruled olfactory cues from mangrove/seagrass water. Mapping these preferences to the ecology of ontogenetic movements, our results suggest sequential cue use would indeed aid successful orientation to novel key habitats in early life.     

Appraisal of visual assessments of habitat complexity and benthic composition on coral reefs

Visual assessments of topographic habitat structure and benthos on coral reefs were appraised using quantitative data collected from 16 replicate surveys within each of 21 sites on Seychelles reefs. Results from visual assessments of reef benthos were similar to those obtained using techniques frequently used to assess benthic complexity and composition. Visual estimates of habitat topography were correlated with rugosity, reef height and holes of 10–70 cm diameter, whilst visual estimates of benthic composition were very similar to those obtained from line intercept transects. Visual estimates of topography correlated strongly with species richness of fish communities and explained 42% of the variation in these data. The relationship between visual estimates of topography and species richness is strongest with fish 10–30 cm total length (TL), abundance of fish within this size category also correlating positively with topographic visual assessments. Visual techniques are prone to observer bias, however with regular training they can be used to quickly provide a reliable and effective means of assessing habitat complexity and benthos on coral reefs.     

Hawksbill sea turtles in seagrass pastures: success in a peripheral habitat

Hawksbill sea turtles, Eretmochelys imbricata, are closely associated with coral reef and other hard-bottom habitats. Seagrass pastures are peripheral habitats for Caribbean hawksbills. With the decline in quality and quantity of coral reefs, seagrass habitats may become more important for hawksbills. We use data from a 30-year mark-recapture study of hawksbills and green turtles, Chelonia mydas, in the southern Bahamas to assess the quality of a seagrass habitat for hawksbills. Size distribution, residence times, and body condition index for the seagrass hawksbill aggregation are similar to those of hawksbill aggregations over Caribbean reefs. Somatic growth rates of seagrass hawksbills are in the upper range of those reported for reef hawksbills. Based on these parameters, peripheral seagrass habitats can support healthy, productive hawksbill aggregations. During the 30-year study, a sixfold variation in green turtle density in the study area did not affect the productivity or body condition of hawksbills.     

How well do sunken vessels approximate fish assemblages on coral reefs? Conservation implications of vessel-reef deployments

The amount of artificial habitat (termed ??artificial reef??, AR) in marine systems is rapidly increasing, yet the effect of most types of AR on reef communities remains unknown. We examined the role of well-established vessel-reefs in structuring coral reef fish assemblages by comparing assemblages on 7 World War II wrecks (>65?years old) to those on interspersed coral patch reefs of comparable size in a tropical lagoon. Fish abundance, species richness, diversity and feeding guild structure on wrecks were similar to natural reefs; however, species composition differed between the two reef types (R?=?0.189?C0.341, average dissimilarity: 67.3?C68.8?%). Despite being more species-rich and diverse, fish assemblages on larger wrecks were less similar to assemblages on their adjacent natural reefs than smaller wrecks. Wrecks may also have affected fish abundance on adjacent natural reefs, with reefs adjacent to larger wrecks supporting higher abundances than reefs adjacent to smaller wrecks. Our results indicate that increases in vessel-reef habitat may not greatly affect reef fish assemblage parameters, but may affect the relative abundances of particular species.     

Ultraviolet photosensitivity and feeding in larval and juvenile coral reef fishes

The ability of young coral reef fishes to feed using solely ultraviolet-A (UV-A) radiation during ontogeny was examined using natural prey in experimental tanks. Larvae and juveniles of three coral reef fish species (Pomacentrus amboinensis, Premnas biaculeatus and Apogon compressus) are able to feed successfully using UV-A radiation alone during the later half of the pelagic larval phase. The minimum UV radiation intensities required for larval feeding occur in the field down to depths of 90–130 m in oceanic waters and 15–20 m in turbid inshore waters. There was no abrupt change in UV sensitivity after settlement, indicating that UV photosensitivity may continue to play a significant role in benthic juveniles on coral reefs. Tests of UV sensitivity in the field using light traps indicate that larval and juvenile stages of 16 coral reef fish families are able to detect and respond photopositively to UV wavelengths. These include representatives from families that are unlikely to possess UV sensitivity as adults due to the UV transmission characteristics of the ocular media. Functional UV sensitivity may be more widespread in young coral reef fishes than in the adults, and may play a significant role in detecting zooplanktonic prey.     

Stable C and N isotope analysis elucidated the importance of zooplankton in a tropical seagrass bed of Santiago Island,Northwestern Philippines

The role of zooplankton in a tropical seagrass ecosystem was investigated in milkfish farms pollution-impacted and -unimpacted seagrass beds in Santiago Island coral reefs, Northwestern Philippines. The aim was to compare between the two sites: (1) abiotic factors and zooplankton community parameters, and (2) the trophic structure using C and N stable isotopes. Low water (98–119?mV) and sediment (–121 to ?138?mV) Oxidation Reduction Potential values indicated a reducing environment in the impacted site. Zooplankton in the impacted site showed the typical community response to eutrophication (low diversity, but high total abundance due to the dominance of the cyclopoid copepod Oithona oculata), generally few elevated δ¹⁵N values, but a significant shift towards depleted ¹³C due to the organic enrichment of fish-farm feeds. Apart from suggesting a highly complex food web with POM and zooplankton as main food sources in the unimpacted site, the Bayesian mixing model simulation generated reduced complexity in feeding interactions between basal sources, zooplankton, and fish including adults of a key fish species, Siganus fuscescens, in the impacted sites. In this study, C and N stable isotope analysis has clarified the importance of zooplankton as fish prey in a seagrass bed food web.     

Recruitment and ontogenetic habitat shifts of the yellow snapper (<Emphasis Type="Italic">Lutjanus argentiventris</Emphasis>) in the Gulf of California

We examined recruitment and ontogenetic habitat shifts of the yellow snapper Lutjanus argentiventris in the Gulf of California, by conducting surveys and collections in multiple mangrove sites and major marine coastal habitats from 1998 to 2007. Over 1,167 juvenile individuals were collected and 516 otoliths were aged to describe the temporal pattern of the settlement. L. argentiventris recruits in mangroves, where juveniles remain until they are approximately 100 mm in length or 300-days-old. Back-calculated settlement dates and underwater surveys indicated a major recruitment peak during September and October, around 8 days before and after the full moon. The majority of mangrove sites in the Gulf of California had a similar L. argentiventris average size at the beginning of the settlement season for the cohort of 2003; although there were significant differences in individual sizes at the end of the nursery stage. When sub-adults leave mangroves, they live in shallow rocky reefs and later become abundant in deeper rocky reefs. The density of migratory individuals (10–20 cm SL) decreased exponentially as the distance between a reef and a nearby mangrove site increased. This finding has important implications for local fishery regulations and coastal management plans.     

Estuarine Vegetated Habitats as Corridors for Predator Movements

Abstract: The spatial proximity of one habitat to another can strongly influence population and community dynamics. We investigated whether the proximity of intertidal oyster reefs to vegetated estuarine habitats, salt marshes, and seagrass beds, affects the abundance and community structure of benthic macroinvertebrates on reefs and predator-prey interactions between mobile predators and bivalves living on reefs. Benthic macroinvertebrate abundance was highest on reefs spatially separated from salt marshes. Macroinvertebrate species richness was highest on reefs separated from both salt marshes and seagrass beds. Comparisons of predation on juvenile bivalves transplanted to reefs for 7–12 days indicated that survivorship of clams was greatest on reefs spatially separated from both salt marshes and seagrass beds, whereas reef proximity to vegetated habitats did not affect the survivorship of oysters. The foraging behavior of blue crabs may explain patterns of macroinvertebrate abundance and clam survivorship among reefs with different proximity to vegetated habitats. In experiments conducted in 30-m² field enclosures, blue crabs had higher predation rates on hard clams transplanted onto artificial reefs adjacent to salt marshes or seagrass beds than on reefs separated from both habitats by unvegetated sand bottom. Thus, vegetated habitats appeared to act as corridors by facilitating the access of blue crabs to oyster reefs and enhancing the intensity of blue crab predation. Such an understanding of the effects of landscape characteristics of estuarine habitats on their value as habitats for estuarine organisms can be used to predict the consequences of habitat fragmentation on ecosystem function and to improve strategies for habitat and species conservation and restoration.     

Flux by fin: fish-mediated carbon and nutrient flux in the northeastern Gulf of Mexico

Seagrass meadows are among the most productive ecosystems in the marine environment. It has been speculated that much of this production is exported to adjacent ecosystems via the movements of organisms. Our study utilized stable isotopes to track seagrass-derived production into offshore food webs in the northeastern Gulf of Mexico. We found that gag grouper (Myctereoperca microlepis) on reefs as far as 90 km from the seagrass beds incorporate a significant portion of seagrass-derived biomass. The muscle tissue of gag grouper, a major fisheries species, was composed on average of 18.5–25% seagrass habitat-derived biomass. The timing of this annual seagrass subsidy appears to be important in fueling gag grouper egg production. The δ³⁴S values of gag grouper gonad tissues varied seasonally and were δ³⁴S depleted during the spawning season indicating that gag utilize the seagrass-derived biomass to support reproduction. If such large scale trophic subsidies are typical of temperate seagrass systems, then loss of seagrass production or habitat would result in a direct loss of offshore fisheries productivity.     

Fish assemblages in seagrass beds are influenced by the proximity of mangrove forests

Mangrove forests and seagrass beds frequently occur as adjacent habitats in the temperate waters of southeastern Australia. At low tide when fish cannot occupy mangroves they might utilise adjacent habitats, including seagrass. We first sampled small fish from seagrass beds close to and far from mangroves in the Pittwater estuary, NSW, Australia. Seagrass beds close to mangroves had a greater density of fish species than beds far from mangroves (close: mean 16.0 species net⁻¹, SE 1.0; far: 13.2, 1.3; P < 0.05). In particular, juvenile fish were in greater densities near to than far from mangroves (close: 5.3, 0.4; far: 3.1, 0.4; P < 0.05). We then sampled the mangrove forests during the high tide and seagrass beds during the low tide, in beds along a continuum of distances from mangroves. Multivariate analysis showed that fish assemblages differed with distance from mangroves, and the differences were attributed to the composition of the fish assemblage (i.e. presence/absence of fish species), not the abundances of individual species. In particular, fish that utilise mangrove forests at high tide were found in greater species densities and species richness in seagrass nearer to mangroves. A negative relationship was found between the density of mangrove-utilising fish species and the distance of the bed from mangroves (R ² = 0.37, P < 0.05). This confirms the important connectivity between mangroves and seagrass for fish in temperate Australian waters.     

Importance of macroalgal fields as coral reef fish nursery habitat in north-west Australia

Macroalgal fields are a feature of the shallow tropical benthos, yet their importance for coral reef fish population dynamics remains poorly understood. The abundance of fish recruits was recorded using underwater visual census at six macroalgal and 11 coral reef sites in the Montebello and Barrow Islands. Surveys identified 6,935 individual recruit fish from 105 species, 54 genera and 20 families. Of these, 1,401 recruits from 48 species, 31 genera and 14 families were observed in macroalgal sites. Sixteen of the 105 recruit species (15.2 %) were observed exclusively at macroalgal sites. Forty-two (87.5 %) of these species have been observed as adults on adjacent coral reefs. Species composition of fish recruits differed significantly between the two habitats. Corallivore, small omnivore and zooplanktivore recruits had significantly higher numbers in the coral sites, while the results clearly demonstrate that juveniles, within the genera Lethrinus and Choerodon, as well as large algal croppers, are predominantly found at macroalgal (74–100 %) rather than coral-dominated sites. High-canopy macroalgae cover was positively correlated with abundance of these taxa, particularly Lethrinids (r ² = 0.40). This study is the first to highlight the important attributes of tropical macroalgal fields and suggests that they have a similar role to seagrass meadows as essential juvenile habitat, thus warranting greater attention in conservation planning and ecological studies.     

A floating mid-water coral nursery as larval dispersion hub: testing an idea

The global decline in reef health has prompted the need for effective management methodologies, including the development of active restoration measures. One such approach is the ‘gardening concept’ that involves use of underwater nurseries where coral fragments are farmed before their transplantation into denuded reefs. Here we document enhanced sexual reproduction in colonies of the coral Stylophora pistillata cultured in mid-water floating nursery situated in nutrient enriched water, near the fish farms in Eilat, Red Sea. We found that after 2 years of nursery, the average number of oocytes per polyp in farmed colonies was ca. 35% higher than in corresponding naturally growing colonies. Small branches in the nursery developed gravid colonies that released equal (or more) numbers of planula larvae as compared to similar size, 5-year old naturally growing colonies. These nursery-borne planulae possessed more zooxanthellae and contained more chlorophyll per larva. While settled and metamorphosed in equal rates compared to planulae originated from reef-grown colonies, the nursery borne planulae developed faster growing young colonies. We estimate that a coral nursery could generate, during the reproductive season, tens of millions of planula larvae and therefore should be regarded as a ‘larval dispersion hub’ that can be used as a management tool for natural recruitment enhancement.     

Spatial and temporal variation in coral recruitment on the Great Barrier Reef: Implications for dispersal hypotheses

Over 15 000 coral recruits were counted on settlement plates from three mid-shelf reefs and six fringing reefs in the northern section of the Great Barrier Reef during two summers (1986 and 1987) and one winter (1987). The density of coral recruits on some settlement plates from a fringing reef was up to 4.88 cm^–2, the highest value ever reported. Mean density of recruits was greater on fringing reefs (81.1 recruits/settlement plate) than on mid-shelf reefs (15.6 recruits/settlement plate), but there was greater spatial variation in abundance of recruits between the fringing reef sites. Other differences between the mid-shelf reefs and the fringing reefs were that different taxa were dominant, and that settlement orientation differed, with mid-shelf recruits settling preferentially on horizontally oriented surfaces and fringingreef recruits preferring vertical surfaces. Of the three midshelf reefs, Green Island reef recorded the highest recruitment rate for each of the two summers, despite having a depauperate adult coral population following predation by the asteroidAcanthaster planci. This suggests that coral larvae frequently travel between reefs. In contrast with an earlier study, there was no consistent difference in abundance of recruits between forereef and backreef locations. Overall, the results indicated great spatial variation in the availability of coral larvae, both on the scale of whole reefs and within-reef habitats.     

Discarded queen conch (<Emphasis Type="Italic">Strombus gigas</Emphasis>) shells as shelter sites for fish

Within the Caribbean millions of queen conch (Strombus gigas Linnaeus) are harvested each year and shells discarded randomly or as middens. Fish use of discarded conch shells was investigated in four different habitat types: sand, seagrass beds, mangrove forests, and coral reefs. The study was carried out in the waters off South Caicos, Turks and Caicos Islands (TCI), between October 2003 and January 2004. The density of discarded shells was greatest near coral reefs; however, the percentage of shells occupied by adult fish was higher in isolated shells on sand and in mangrove habitats. Juvenile fish also showed a preference for sheltering in conch shells relative to other microhabitat types on sandy plains and in mangrove and seagrass habitats. Differences in use of single shells by fish in different habitats were attributed to differences in piscivore abundance and habitat complexity. Although not all isolated shells were occupied by fish, all conch middens deposited by fishermen had fish inhabitants. Examination of fish use of conch middens in three habitat types and conch piles of one, three, and five shells constructed on sand found both fish diversity and abundance increased on conch middens of increasing size. This study suggests that disposal of conch shells as large middens in habitats of low complexity will increase the amount of shelter present and may enhance fish populations in these habitats.Communicated by J.P. Grassle, New Brunswick     

Relative intensity of predation on the French grunt, Haemulon flavolineatum, during diurnal, dusk, and nocturnal periods on a coral reef

Established hypotheses state that the rate of predation on coral reef fish should be highest during crepuscular periods (dawn and dusk) intermediate diurnally, and lowest nocturnally. We examined the relative risk of predation on juvenile French grunts (Haemulon flavolineatum Desmarest) during diurnal, dusk, and nocturnal periods on the fore- and back-reef at Teague Bay, U.S. Virgin Islands in July and August 1996. Tethering-devices recorded the exact amount of time between attaching a prey fish to its tether and subsequent predation on the prey fish. As tethering of prey usually inflates the actual rate of predation, times from our tethering devices were used to establish only the relative predation risk among treatments. During 3-h diurnal and nocturnal tethering experiments, relative predation was significantly higher during the nocturnal period, and differences between side of reef were not significant. In 30-min tethering experiments, which included all three time periods, the relative predation risk was significantly higher during dusk and nocturnal periods than during the diurnal period. Relative predation was not significantly different between the dusk and nocturnal periods, or between side of reef during any time period. The unexpected finding that the diurnal period had the lowest relative risk of predation indicates that the timing of predation events on reefs, as well as the adaptive reasons for nocturnal larval settlement, may need to be re-examined. Received: 11 February 1997 / Accepted: 21 October 1998     

Trophic ecology of coral reef gobies: interspecific,ontogenetic, and seasonal comparison of diet and feeding intensity

In fishes, a small body size may facilitate cost-effective exploitation of various primary and secondary food resources, but may pose difficulties associated with digestion of plant material and finding sufficient food in a foraging area potentially restricted by a high risk of predation. We examined the trophic ecology of five common, small-bodied coral reef fish from the family Gobiidae. For each species, we determined diet composition, feeding bite rate, foraging substrate, and feeding behaviour, and examined whether diet composition and feeding bite rate changed ontogenetically and seasonally. The five species showed a diverse range of trophic modes: Amblygobius bynoensis and Amblygobius phalaena were herbivores, Valenciennea muralis was a carnivore, Asterropteryx semipunctatus a detritivore, and Istigobius goldmanni an omnivore. Both the herbivores and detritivore supplemented their diet with animal material. The consumption of a wide range of dietary resources by the two smallest species with the most restricted mobility (A. semipunctatus and I. goldmanni) may ensure energy requirements are met within a restricted foraging area. There was a significant difference in mean feeding bite rate among species, with carnivore > herbivore > omnivore > detritivore. None of the species exhibited an ontogenetic shift in diet composition or increase in feeding bite rate, indicating that (1) postmaturation growth is not facilitated by a higher quality diet or increased feeding intensity following maturation, and (2) their small body size does not preclude herbivory. The herbivores had the highest gut:fish length ratio, which may facilitate plant digestion. While diet did not change seasonally, the mean feeding bite rate was significantly lower in winter than summer for four of the study species.     

A link between biologically imported particulate organic nutrients and the detritus food web in reef communities

Previous work with planktivorous fishes has shown that they import particulate organic and inorganic material to reefs in the form of fecal pellets, which, in part, are deposited in crevices on the reef where these fishes shelter during their inactive period. Since these feces do not accumulate in fish shelters, we predicted that some of the feces could be rapidly consumed by reef detritivores. We examined the attractiveness of fish feces to potential reef detritivores by placing traps baited with planktivorous fish feces, along with unbaited control traps, in crevices on rocky reefs at Santa Catalina Island, California, USA, between June 1982 and November 1983, and on coral reefs at St. Croix, U.S. Virgin Islands, during June 1983. Significantly more animals (the majority being crustaceans) were trapped in the baited traps compared to the unbaited controls on both reefs. There was also a significant association between the presence of trapped animals and fish feces at Santa Catalina Island (p = 0.009); this association was not quite as strong in St. Croix (p = 0.069). The consumption by shrimp of feces marked with carmine particles and, in turn, the predation on these shrimp by a reef fish demonstrates the links between this type of imported particulate organic and inorganic material and the food web of the reef community.Please address all correspondence and requests for reprints to Dr. Miller at California State University, Long Beach